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post #1 of 46 (permalink) Old September 23rd, 2018, 00:50 Thread Starter
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SSM Build in the Works

Hey all, I'm Chris and I currently run a 2006 S2000 in STR (my wife also drives with me). I haven't been to Nationals in 5 years now for budget, family, or other reasons but I know this is definitely my sport. The ND Miata has taken CS and STR by storm and many S2000 owners have jumped ship to the ND1 in STR showing the ND chassis' promise; not sure if the S2000 is dead in STR now (especially since mine's not a CR) but with the ND2 coming out in 2019 it's not looking good. I picked up my 1992 MR2 back in September of 2017 and have been slowly working on it trying to get it to start. Original plan was to put a 2GR-FE in it and running it at SCCA Track Night events for fun until the whole STR issue mentioned above the past couple of months. I saw Martin Valent's car and that sparked a huge interest in building an SSM MR2 and with the 2018 rule change allowing engines from different manufacturers it got my wheels turning.

I considered sticking with the 2GR until I found out I'd need to be in the 400-500 whp range to be competitive meaning it would need forced induction. I then started thinking about a K24 turbo swap which then led me to the SSM rulebook for minimum weights. Unless I build a K20 instead of a K24 I wouldn't be near the minimum weight that would be allowed with the 3S-GTE. After speaking with I believe Martin at TM Racing it sounds like sticking with the 3S is the way to go and speaking with a local MR2-autocrosser in Texas about jumping into SSM he said he'd probably go with the ATSRacing "formula" for hitting the 450whp mark.

I'll give my story up until now in the post below but in short I'm looking to figure out a couple of things up front here in regards to car setup.

1992 MR2, 5S-FE, S54, t-tops
Non-PS, Non-ABS

Present concerns...
1. Do I need PS? I haven't driven the non-PS rack yet but I'm guessing it's too slow for autox.
2. Is ABS essential for autox and track events or is non-ABS adequate? I'm looking into Wilhelm's docs on BBK and proportioning valve combos.
3. Fuel tank is in a sad state. Should I replace with OEM for now or go straight to fuel cell?
4. Are there any other concerns about the chassis I have now for being competitive? I figure t-tops can be removed or replaced with lightweight panels.
5. Before I do any suspension refresh, are there certain subframes or components I need to swap to?

Build plans...
- Fix or replace fuel tank with OEM or fuel cell.
- Research and find any grounding issues. I read there's a huge concern with grounds & fires.
- Get the car running with the 5S-FE
- Clean & Refresh the suspension components
- Purchase Swaybar Reinforcement Mounts
- Fix the dash separation issue
- Fix the cancer issues
- Get a 3S-GTE to swap in, probably run that in the car for a while and save funds to rebuild to 450 whp (oversimplified for sure)
- Get the E153 transmission, axles, & rear turbo hubs
- Research on the gearing needed (Camry gearset?)
- Aero... that'll be fun
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post #2 of 46 (permalink) Old September 23rd, 2018, 00:54 Thread Starter
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Prologue aside, here's a bit of history on the car thus far...

I purchased this 5S-FE from a friend whom was starting to sell off project cars in case he had to PCS to a different location. He bought the car not running & he tried to put a new battery in and said it fried the fusible link on the positive cable. It was definitely fried so I installed a new fusible link and started checking for shorts to ground and found one on the positive battery cable. Tracing wiring diagrams it led me to the brake pedal fuse which was still intact surprisingly. There's a plastic pad on the brake pedal that presses against the switch to turn the rear brake lights off which was no longer there. I bought a new plastic pad and that fixed that closed-circuit. That allowed me to connect the battery and get dash lights, brake lights, etc working but the car wouldn't crank over. I think my friend might have put the battery in backwards by accident but he thinks he put it in correctly, we may never know.

The engine harness was an absolute mess from the guy my friend purchased it from. The harness was cut, separate power wires ran through the grommet to the injectors, damaged connects, etc. I cut my losses and purchased a used 5S-FE harness from eBay, removed the old, swapped over connectors, started installing it and wondered why the alternator wires stopped short... the previous owner had swapped in a 5S-FE from a FWD platform where the alternator sits on top rather than on the lower backside. THAT's why the alternator wiring was extended... since I didn't want to spend another $60 on an alternator bracket + $60 on the tensioner pulley from eBay I decided to extend the harness to the alternator as well. All is good now, I go to crank it over and it does! No start though... air is good, compression is good (210psi across all cylinders), spark is good, fuel... no fuel. Jumped the priming wires and nothing. Checked the power wires going to the pump and there's 12V. I even cracked open the banjo bolt to the fuel filter in case it was clogged but no fuel when attempting to prime. Last test is I sprayed starter fluid into the throttle body and the car was trying to start so the fuel pump is dead.

That leads me to where I am now. I've dropped the fuel tank and WOW what a mess it is inside after the car sat for over 2 years. Fuel smells like old varnish and the tank is definitely cruddy inside. I got a quote for $175 minimum to clean and line my current tank from a local radiator shop and I've reached out to people in Texas for used ones from a running car. This has also led me to consider installing a fuel cell in the frunk.
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post #3 of 46 (permalink) Old September 23rd, 2018, 22:14
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The manual steering is about 10-15lbs lighter, but the ratio is terrible, I think it's like driving a bus. The PS rack has a quicker ration: I've converted mine to power steering, and you can change the pinion to make that rack quicker still.

I don't think ABS is essential, and I think it would be nice if you could do something a bit more modern, but the original system is pretty archaic.

I'd probably repair or replace the stock tank. It's nice that it's in the center of the car so the weight distribution doesn't change from full to empty.

The chassis' are all quite similar. There were some suspension changes in 1993 to make it a little less snappy, (I think Honda did something similar from the AP1 -> AP2). I don't think it really matters too much which one you have if you are going to change all the other components out. Some people may have different personal preferences.

There are a few variations of the E153, and you'll have to do a little math with the tire diameters and rev limit that you are planning to use to see at what speeds you'll end up with in gear and compare that with the length of the courses you are running to see if it's worth a change. I would highly recommend a proper LSD though, the optional viscous diff does basically nothing.
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post #4 of 46 (permalink) Old September 25th, 2018, 00:05 Thread Starter
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Cheers, thanks immorality for the tips. It sounds like PS is the way to go based on rack ratios and I do like how you can change to a quicker pinion, that's with the Mk3 pinion in the Mk2 rack, right?

Interesting notes on the fuel tank. It'd be about a 40 lbs difference from full to 1 gallon left with an 8 gallon fuel cell which I guess might somewhat affect the balance. I just read this afternoon someone mentioning that the plastic baffle at the bottom of the tank would get damaged from typical tank restoration linings. I'm not sure how true that is but someone concerning if I want to repair my current one; I'd rather swap in a good used condition tank given the status of mine.

Yeah, Honda changed the subframe on the S2000 and widened the wheel stagger between the two chassis to tone down the playful rear end. It sounds like Toyota did a similar swap on the crossmember regarding toe in/out on bump/rebound respectively on the early model vs just toe-in on the later model. Sounds like it's potentially better to keep the early model and adjust with suspension arms/links.

Good to know on the transmission variations, thanks. That sucks to hear about the viscous diff; I'm still running my OEM torsen in the S2000 as well as several others that are in the top STR spots.
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post #5 of 46 (permalink) Old October 5th, 2018, 18:37
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The VLSD works well on a street car, but I suspect with the power you'll be making and the grip you'll produce in SSM, you'd be best off with an aftermarket LSD. I've heard good things about the Quaife before. I'm sure there are other options too.

I used to autox these cars in Stock class on R-tires back in the day. My 93NA was a manual steering no-ABS car. My 93T has the works. For an autocross car, especially with a lot of power, I'd recommend the PS and the ABS. I've found the ABS to be quite good actually, even though it's only a 3-channel system. It doesn't suffer from the ice-mode stuff a lot of modern systems can have. For the steering, I thought I heard years ago that there was an aftermarket steering quickener and it was only for the PS rack OR only for the manual rack... and I forget which it was. Perhaps a look at some past SSM build threads will reveal answers. Either way, I recommend that option, PS or not. When you have to correct a slide, it'll be a lot easier with a flick of the wrists than being all elbows etc. Since you come from the S2k, even the faster of the two SW20 steering racks is going to feel really slow to you.

The cool thing about the OEM tank is that you can run it pretty low without fuel starving. The *really* cool thing about it is that where it's located, handling balance will change very little as the fuel level changes. With a fuel cell in the frunk you will want to keep the fuel level more constant at events which means more frequent small fill-ups.

Regarding power and turbo sizing, I'd put some thought into achieving quick spool and linear response. That's going to be worth more on an SSM MR2 than an extra 30-50hp, IMO. Off the top of my head I've heard the GT28RS is a solid choice for reasonable power, quick spool and driveability. I've also heard EBCs offer quicker spool and more stable boost control than MBCs.

Regarding subframes and suspension updates, Alex Wilheilm has done a lot of maths on this and sells (or did?) some arms that might be of interest to you. He'd be a good person to talk to.

The funny thing is, in the case of the SW20 and the AP1/AP2, when the suspension, wheels and tires were updated for the mid cycle refresh, oversteer came less readily but when it did come, it was much more sudden. The early cars are loose but easier to control in that transition between neutral and oversteer. Just an interesting anecdote. I've owned a couple 93 MR2s and an '04 S2k, and driven early models of both cars on tracks.

Good luck with the build! I love seeing SSM MR2s, and I think it's a competitive platform. I want to do a "simple" 2GR SSM MR2, in my dreams.

'93 Turbo | SCCA C-Stock

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post #6 of 46 (permalink) Old October 8th, 2018, 19:11
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Since you don't have an engine already, you might want to give the 2GR some more thought as a starting point for SSM. It may be "only" about 280-290whp out of a stock motor as swapped, but the power band and linearity helps offset that a LOT. Not saying that 290whp is "enough" for a serious SSM build, but it's a very good start. From there, adding a little boost could get you to whatever number you want while still having a better power band than you are going to get out of a 4 cylinder. No replacement for displacement and all that It's not quite as straight forward to boost one, a lot more custom work would be required, but it can be done. Personally I like autocrossing my 2GR swapped car WAY more than I did my built 3s that had an extra 100hp.

Like others have said, definitely go for the power steering rack, with the quick ratio pinion (word on the street is it's the pinion from the Spyder rack). There is no quick ratio option for the manual rack, and (in my opinion), heavy steering just makes it hard to be smooth.

ABS, I can go either way. My current car doesn't have it, and I don't really miss it. But it does make it easier to drive to the limit, provided it works correctly. I did at one point experience some "ice mode" like symptoms on mine, but I'm not sure if it was due to dirty sensors or just the way it works. Overall, I wasn't a huge fan of the ABS in my 91t... I did retrofit a 93+ ABS ECU into that car, which improved it quite a bit.

Like Randy said, keep the OEM tank. You can run it down to almost nothing without starving, and the location is perfect. If you want to drop weight, maybe cut it in half (or cut both ends off and keep the center 1/3 out where the pickup is) and weld up the ends. Might have to get custom to re-mount it in the stock location, but if it's an autocross only car and you don't mind having a 4 gallon tank, it could work well I think.

Personally, I have never driven a 93+ car. I have done a lot of work to tame the 91 without neutering it, and in my admittedly biased opinion, that's the way to go.


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post #7 of 46 (permalink) Old October 9th, 2018, 17:51 Thread Starter
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Originally Posted by BryanH View Post
For the steering, I thought I heard years ago that there was an aftermarket steering quickener and it was only for the PS rack OR only for the manual rack... and I forget which it was. Perhaps a look at some past SSM build threads will reveal answers. Either way, I recommend that option, PS or not. When you have to correct a slide, it'll be a lot easier with a flick of the wrists than being all elbows etc. Since you come from the S2k, even the faster of the two SW20 steering racks is going to feel really slow to you.

The cool thing about the OEM tank is that you can run it pretty low without fuel starving. The *really* cool thing about it is that where it's located, handling balance will change very little as the fuel level changes. With a fuel cell in the frunk you will want to keep the fuel level more constant at events which means more frequent small fill-ups.

Regarding power and turbo sizing, I'd put some thought into achieving quick spool and linear response. That's going to be worth more on an SSM MR2 than an extra 30-50hp, IMO. Off the top of my head I've heard the GT28RS is a solid choice for reasonable power, quick spool and driveability. I've also heard EBCs offer quicker spool and more stable boost control than MBCs.
...
Good luck with the build! I love seeing SSM MR2s, and I think it's a competitive platform. I want to do a "simple" 2GR SSM MR2, in my dreams.
Much appreciated on the info. It sounds like from my research there are two options for MK2 Power Steering racks. Option 1 is getting the pinion from a MK3 power rack and Option 2 seems to be a custom pinion made by a company which I'm not sure if they're still producing or not.

It's sounding like the consensus is to stick with the OEM despite how much of a pain they are to find it non-rusted condition. Definitely agreed on quick spool over added power, I can definitely appreciate that given the application of the sport.


Quote:
Originally Posted by Alex W View Post
Since you don't have an engine already, you might want to give the 2GR some more thought as a starting point for SSM. It may be "only" about 280-290whp out of a stock motor as swapped, but the power band and linearity helps offset that a LOT. Not saying that 290whp is "enough" for a serious SSM build, but it's a very good start. From there, adding a little boost could get you to whatever number you want while still having a better power band than you are going to get out of a 4 cylinder. No replacement for displacement and all that It's not quite as straight forward to boost one, a lot more custom work would be required, but it can be done. Personally I like autocrossing my 2GR swapped car WAY more than I did my built 3s that had an extra 100hp.

Like others have said, definitely go for the power steering rack, with the quick ratio pinion (word on the street is it's the pinion from the Spyder rack). There is no quick ratio option for the manual rack, and (in my opinion), heavy steering just makes it hard to be smooth.

ABS, I can go either way. My current car doesn't have it, and I don't really miss it. But it does make it easier to drive to the limit, provided it works correctly. I did at one point experience some "ice mode" like symptoms on mine, but I'm not sure if it was due to dirty sensors or just the way it works. Overall, I wasn't a huge fan of the ABS in my 91t... I did retrofit a 93+ ABS ECU into that car, which improved it quite a bit.


Like Randy said, keep the OEM tank. You can run it down to almost nothing without starving, and the location is perfect. If you want to drop weight, maybe cut it in half (or cut both ends off and keep the center 1/3 out where the pickup is) and weld up the ends. Might have to get custom to re-mount it in the stock location, but if it's an autocross only car and you don't mind having a 4 gallon tank, it could work well I think.

Personally, I have never driven a 93+ car. I have done a lot of work to tame the 91 without neutering it, and in my admittedly biased opinion, that's the way to go.
Hey Alex, I've been watching your stuff for a while and I've definitely had the suspension geometry fix kit on my short-list for mods for my car. Thanks for doing the legwork on all of that. Regarding the 2GR, man I really like the sound of that engine but when I found out I would need around 450 whp to be competitive in SSM with this car that kind of put the 2GR out of the running since it would also require boost and push the minimum weight of the car 337 lbs more than the 3S. NA 2GR would only be 22lbs heavier, minimum-weight wise. The original purpose of the MR2 I got was to be a fun HPDE machine which the 2GR would work perfectly for as you've found but the whole SSM crept in, hehe.

I attached a minimum weight chart I made not long ago. It 'should' be correct for the 2018 rulebook.

The next question is how much of a pain is it going to be to get the PS rack, pump, reservoir, frunk wiring harness, and steering sensor, yay... I also read you have to relocate a mounting tab for the PS rack.
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post #8 of 46 (permalink) Old October 9th, 2018, 21:56
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Much appreciated on the info. It sounds like from my research there are two options for MK2 Power Steering racks. Option 1 is getting the pinion from a MK3 power rack and Option 2 seems to be a custom pinion made by a company which I'm not sure if they're still producing or not.

It's sounding like the consensus is to stick with the OEM despite how much of a pain they are to find it non-rusted condition. Definitely agreed on quick spool over added power, I can definitely appreciate that given the application of the sport.

Hey Alex, I've been watching your stuff for a while and I've definitely had the suspension geometry fix kit on my short-list for mods for my car. Thanks for doing the legwork on all of that. Regarding the 2GR, man I really like the sound of that engine but when I found out I would need around 450 whp to be competitive in SSM with this car that kind of put the 2GR out of the running since it would also require boost and push the minimum weight of the car 337 lbs more than the 3S. NA 2GR would only be 22lbs heavier, minimum-weight wise. The original purpose of the MR2 I got was to be a fun HPDE machine which the 2GR would work perfectly for as you've found but the whole SSM crept in, hehe.

I attached a minimum weight chart I made not long ago. It 'should' be correct for the 2018 rulebook.

The next question is how much of a pain is it going to be to get the PS rack, pump, reservoir, frunk wiring harness, and steering sensor, yay... I also read you have to relocate a mounting tab for the PS rack.
There is some debate as to if the old V-Max pinion was anything other than a reconditioned Spyder pinion. Seems that they are very similar at any rate, if not identical. But I haven't compared them. I have a V-Max from back in about 2006, just repeating what I have read regarding the Spyder option.

Regarding weight, do you think it's actually possible to get a 3S based car down close to minimum weight within the SSM rule set? My car is about 2600 (1/4 tank of gas, no driver), and while I haven't gone totally nuts with weight reduction, that's with no A/C, light weight seats, fiberglass hood, no abs, and a few other little things that drop a few lb here and there. There are certainly other things to lose a bit more, but to drop another 250lb (to get down to 2350ish) seems tough. But I am definitely interested in talking SSM legal weight reduction...

Doing the power steering swap, you can relocate a mounting point if you want, but I didn't bother. The rack ends up a bit off center, I built a travel limiter for the RH side to even out the steering angle left to right. You lose a bit of steering angle, but the up side is my tires don't rub at full lock any more (so, I lost travel that I didn't really "have" to begin with). Can probably find all the parts in one place from someone parting out a car.


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post #9 of 46 (permalink) Old October 9th, 2018, 23:24 Thread Starter
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There is some debate as to if the old V-Max pinion was anything other than a reconditioned Spyder pinion. Seems that they are very similar at any rate, if not identical. But I haven't compared them. I have a V-Max from back in about 2006, just repeating what I have read regarding the Spyder option.

Regarding weight, do you think it's actually possible to get a 3S based car down close to minimum weight within the SSM rule set? My car is about 2600 (1/4 tank of gas, no driver), and while I haven't gone totally nuts with weight reduction, that's with no A/C, light weight seats, fiberglass hood, no abs, and a few other little things that drop a few lb here and there. There are certainly other things to lose a bit more, but to drop another 250lb (to get down to 2350ish) seems tough. But I am definitely interested in talking SSM legal weight reduction...

Doing the power steering swap, you can relocate a mounting point if you want, but I didn't bother. The rack ends up a bit off center, I built a travel limiter for the RH side to even out the steering angle left to right. You lose a bit of steering angle, but the up side is my tires don't rub at full lock any more (so, I lost travel that I didn't really "have" to begin with). Can probably find all the parts in one place from someone parting out a car.
I'm not 100% sure and I'm only going based off of info I've collected thus far. Whether it's true or not is another thing... I saw a FS post of an SSM MR2 with a claimed weight of 2550 lbs and "min weight of 2397 lbs is acheivable" (https://www.mr2oc.com/45-auto-x/3304...sm2-turbo.html). Otherwise, most weights I hear are like you mentioned 2600+ so I am quite curious myself to know how Randy planned to achieve just shy of 2400 lbs.
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Nice weight chart, but any K series motor isn't going to be allowed in SSM unless the rules changed to allow other swaps from other manufacturers.

Also, I have a Quaife (torsen style) differential in mine and it made a HUGE difference. I would highly recommend it!
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post #11 of 46 (permalink) Old October 10th, 2018, 15:51 Thread Starter
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Nice weight chart, but any K series motor isn't going to be allowed in SSM unless the rules changed to allow other swaps from other manufacturers.
Yep! This year they introduced allowing engines from other manufacturers and it costs you a +150 lbs minimum weight penalty.

16.1 D.1.
Any block that is not sourced from a car of the same brand will be assessed a 150-lb. weight adjustment in addition to all weight calculations in Appendix A. Brands that exist as marketing aliases for the manufacturer will be recognized as equivalents. Swaps involving brands related only at a corporate level are not recognized as equivalents and will be subject to the weight adjustment referenced above.
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Oh man. This thread has me thinking bad thoughts about wrecking my RSX and putting the motor in the MR2... again.
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post #13 of 46 (permalink) Old November 18th, 2018, 11:22
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Any more progress on this? Sounds interesting.

I would say the K20 with a 6 speed would probably make it pretty easy to hit that min weight. The K20 block is quite a bit lighter than a B series, which is obviously lighter than a 3S block. The K series trans is also a lot lighter than an E153. I think they're about 85-90 lbs from memory, while the E153 is like 120+ right?
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post #14 of 46 (permalink) Old November 18th, 2018, 21:38 Thread Starter
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Any more progress on this? Sounds interesting.

I would say the K20 with a 6 speed would probably make it pretty easy to hit that min weight. The K20 block is quite a bit lighter than a B series, which is obviously lighter than a 3S block. The K series trans is also a lot lighter than an E153. I think they're about 85-90 lbs from memory, while the E153 is like 120+ right?
I'm currently stuck waiting to get an OEM fuel tank, pump hanger, and level sender from MR2heaven over in California; with all the fires happening though it's hard for them to work on the cars outside so I'm patiently waiting while they stay safe over there. I tried using electrolysis on the fuel tank I removed from my car and it showed promise but after the thought of running several more passes on it and then rushing to clean with acid, metal prep, then POR-15 seal it before flash-rusting occurred got me to ordering a rust-free one to not deal with that hassle. I attached a couple of photos of how it looked originally cleaning it and then first pass with the electrolysis.

Aside from that, it's going to be a slow-burn build given budget/schedule but also for figuring out the easiest path ahead from those that have paved it before me. The question I'm trying to figure out is if the car can be lightened any further than the K20 turbo's minimum weight of 2515 lbs, if it can then it might be worth sticking with the 3S-GTE to close in on the minimum weight of 2365 lbs; anything to get me anywhere near the SSM Miata at 2070 lbs will help. If I run the K20 turbo, I'd need to figure out rules-wise if I can run an air-to-water setup into the trunk or if there's an issue cutting a "firewall" unless it's only between the driver and engine.
Attached Images
File Type: jpg bad_pump.JPG (687.1 KB, 8 views)
File Type: jpg bad_fuel.jpg (757.8 KB, 4 views)
File Type: jpg bad_tank.jpg (349.7 KB, 4 views)
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post #15 of 46 (permalink) Old November 20th, 2018, 10:23
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I think a K20+turbo MR2 can feasibly get a little lighter than 2515 under SM rules, but I doubt the 3S car can get down that light as Alex W said.


I don't know if I'd completely discount the 2GR. It's a 280-290 rwhp engine with bolt-ons and light tuning. If you actually pushed the development a little more on the engine side with cams, maybe shave the heads, I could totally see getting quite a bit more than that. It won't have that top end rush of a 4 banger turbo setup, but in my experience, a true 400+ rwhp setup on a 2L is going to not be the most punchy thing coming right off slower corners. On a track, yes, the turbo 4 will definitely be faster than the 2GR, but on the average ~70 mph max speed autox course, I don't know. I think the extra speed you gain on straights might be offset with the small amount of lag coming out of the corners.

If you do go with a turbo setup, I would STRONGLY recommend an EFR 7163 T4 twin scroll for your setup. Light weight package (aluminum CHRA + IWG + recirc valve) will really drop some weight off the turbo system as a whole, and it'll belt out 500+ rwhp at full chat, and it responds like a ~250-300 rwhp Garrett due to the lightweight turbine wheel. There's nothing else that comes close. (I can hook you on one if you decide to go down that road, hit me up privately)

I wouldn't go into the trunk for an air-water setup. You're adding too much intake tract length. Just do a tiny, but good air-water core (the eBay ones actually have a ton of pressure drop), and do a small reservoir that's insulated and you put ice in for every run. You can put a small heat exchanger in the stock location for street driving that you can block off with a valve for autox usage (you'd be warming the cold water up), but small amounts of water volume really drive more weight in a hurry. Probably worthwhile to remove any bits like that for serious competition on a prepped car.


Most people say the S54 is a ticking time bomb at higher power levels, but I wonder if they could get through a season? It'd save a ton of weight over an E153 + turbo axles. Some people seem to get by for a while on 2GRs with them, so 2GR + S54 might end up being realistically the lightest engine setup you could put in there from a rules + actual lower weight limit you can achieve.

I'll be trying to follow the build - as it's interesting to try to compete with modern iron with an older car.
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post #16 of 46 (permalink) Old November 20th, 2018, 11:04
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Most people say the S54 is a ticking time bomb at higher power levels, but I wonder if they could get through a season? It'd save a ton of weight over an E153 + turbo axles. Some people seem to get by for a while on 2GRs with them, so 2GR + S54 might end up being realistically the lightest engine setup you could put in there from a rules + actual lower weight limit you can achieve.
I have no personal experience on this, but the general word on the street is that it's hard launches (and higher power levels) that will kill an S54. Might hold up fine for normal street use or even road racing, but autocross, I don't know...


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post #17 of 46 (permalink) Old November 20th, 2018, 16:46
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True, shock loads are much more likely to smoke a gear stack that's on the edge vs. steady state accel.

How much do you reasonably think you could get a 3S-GTE equipped SW20 per SM rules? 2550 lbs? 2500 lbs? I imagine you could go a little light weight on the brakes that would be more autox focused, that's probably good for a solid 15 lbs there over a more track oriented brake setup. All composite panels. Can you do anything to the bumper beams? SM rules seem a little vague there (they mention "front and rear bodywork" not sure if that includes bumper beams, you could make some out of aluminum and probably drop 15-30 lbs depending on how heavy the SW20 ones are). Really lightweight exhaust? Probably not worth much, but it's weight that's far back.

On that note, isn't the 2GR about 30-40 lbs lighter than the 3S-GTE?
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post #18 of 46 (permalink) Old November 21st, 2018, 09:26 Thread Starter
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Quote:
Originally Posted by DefSport View Post
I think a K20+turbo MR2 can feasibly get a little lighter than 2515 under SM rules, but I doubt the 3S car can get down that light as Alex W said.

I don't know if I'd completely discount the 2GR. It's a 280-290 rwhp engine with bolt-ons and light tuning. If you actually pushed the development a little more on the engine side with cams, maybe shave the heads, I could totally see getting quite a bit more than that. It won't have that top end rush of a 4 banger turbo setup, but in my experience, a true 400+ rwhp setup on a 2L is going to not be the most punchy thing coming right off slower corners. On a track, yes, the turbo 4 will definitely be faster than the 2GR, but on the average ~70 mph max speed autox course, I don't know. I think the extra speed you gain on straights might be offset with the small amount of lag coming out of the corners.
I'm all ears to hear the potential for a 2GR but it would have to make upwards of 450 whp. Coming from 270 whp that seems like quite a longshot without forced induction.

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If you do go with a turbo setup, I would STRONGLY recommend an EFR 7163 T4 twin scroll for your setup.
Thanks on that info. I definitely prefer faster spool setups that are torque-ier down low rather than laggy "all up top". I chose the Fiesta ST over the Focus ST for that reason as a daily driver a while back (suspension was much tighter and not as bumbley as well); unfortunately had to get rid of that car for a bigger CX-5.

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I have no personal experience on this, but the general word on the street is that it's hard launches (and higher power levels) that will kill an S54. Might hold up fine for normal street use or even road racing, but autocross, I don't know...
No personal experience either but from what I've read it can "handle it" but the thought of powering 450 whp through a set of Hoosier A7 doesn't sound good for it.
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post #19 of 46 (permalink) Old November 21st, 2018, 09:59
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How much do you reasonably think you could get a 3S-GTE equipped SW20 per SM rules? 2550 lbs? 2500 lbs? I imagine you could go a little light weight on the brakes that would be more autox focused, that's probably good for a solid 15 lbs there over a more track oriented brake setup. All composite panels. Can you do anything to the bumper beams? SM rules seem a little vague there (they mention "front and rear bodywork" not sure if that includes bumper beams, you could make some out of aluminum and probably drop 15-30 lbs depending on how heavy the SW20 ones are). Really lightweight exhaust? Probably not worth much, but it's weight that's far back.

On that note, isn't the 2GR about 30-40 lbs lighter than the 3S-GTE?
Tough to say. I haven't gone crazy with the weight reduction on my car, but I have certainly done some. It's about 2600 with the 2GR and a 1/4 tank of fuel. 3S, yeah, probably 30-40lb more sounds about right from what I remember. It's going to depend on the turbo and intercooler. There are a lot of little areas I could lose some more, some of them cheap some of them not so much...

I'm pretty sure you aren't supposed to touch the bumper bars. Front you could lose some... the rear is actually plastic from the factory and relatively light already.

Brakes, can get about 10lb lighter than stock with my ultralight kit. Can probably get a bit lighter than that if you really got custom with smaller rotors.

Can definitely lose some weight off the exhaust (on my car). The Berk is like 30lb just for the muffler. Should be able to easily drop half of that, maybe more (depending on how much muffler you put on it).

I know Eric Hux has his K-swapped car down in the 2250 range (NA), but I don't know if it would be SSM legal. It should be close though, it has the full interior. Honestly I don't know how he did it, I mean, the K series is light, but that's a big difference.


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post #20 of 46 (permalink) Old November 21st, 2018, 13:49
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I run my 2GR MK2 in SSM. It's around 2650 without me in race trim.(no carbon fiber or aero) It will be tough to be nationally competitive without ~400hp. I have an e153 with a 3.6 final drive for more mph in 2nd gear. I can't imagine an s54 lasting very long on hoosiers.
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