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Discussion Starter #1
So I am a new MR two on her I have a 91 turbo it’s been well-maintained but it has a lot of mileage on it I’m going to turn off the boost and add supporting mods for the stock engine but inevitably I know that I will have to do a motor swap my options are Jen 53SGTE or perhaps someone could tell me something that would be just as reasonable as that with my transmission and wiring harness GEN five motor doesn’t seem too expensive to put into the car.
are there any other engines that people have experience with like K series that would perhaps make more power for a relative cost?
 

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Depends entirely on your budget and mechanical skill level. What are your goals? Is this a weekend driver, track toy, race car? How much power do you want? Power costs cubic dollars, especially when you start getting a 3sgte much past the 300whp mark. Tuning is especially expensive to get right.

By far the easiest route is to rebuild your existing engine so that you know it's fresh. Anything coming from Japan is suspect on quality until proven otherwise, no matter how many compression test videos they make.
 

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I'd tend to agree with a feasibility check on the possibility of a rebuild before anything else.
...are there any other engines that people have experience with like K series that would perhaps make more power for a relative cost?
If you're contemplating a radical K series engine swap, then you might also consider a 2GR swap as well. While the installation is more involved than a 5th gen 3S swap, it's arguably similar in complexity to a K swap except the V6 swap has a lot more documentation & support for it.
 

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Discussion Starter #4
Thanks for the reply guys I was trying to just figure out where I can make power on technically a stock engine so basically if I was to get a fifth GEN engine dropped into the car it wouldn’t be a ton of money I would be doing the work myself my mechanical abilities are very high I could basically do anything down to rebuilding the engine and trans n’The reason that I wanted the fifth GEN was to update the ignition and computer system to OBD two I just figured overall it would run better and be easier to tune
I would like to see somewhere in the 350 to 400 hp range with bolt ons which is why I didn’t know if the fifth GEN could hold that kind of power or if a K swab could hold a power with stock internals and my goals are to have a weekend/Road car race car with a roll cage that I can bring up to the race track and drive on the road course
 

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A K series head is way ahead of any 3S head, you'll make more power with less work on a honda engine. So it's either spend most of your energy and time adapting a k24 or building and finding someone to tune a 5th gen with very little documentation and experience.

You also have to consider a K series can be found in practically any junkyard and parts a plentiful, gen5 was a very limited run and never sold in the US. Just depends on how much of a Toyota purist you are and how bolt in of a swap you want.
 

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If a track car is your goal you really should consider the 2GR as well. Turbos on the track are trouble.
 

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...so basically if I was to get a fifth GEN engine dropped into the car it wouldn’t be a ton of money I would be doing the work myself my mechanical abilities are very high I could basically do anything down to rebuilding the engine and trans n’The reason that I wanted the fifth GEN was to update the ignition and computer system to OBD two I just figured overall it would run better and be easier to tune
Once you start modifying the internals it really doesn't matter what revision 3sgte you start with. I'd be more inclined to remove and rebuild what you have including forged internals and cosmetic head gasket amoung other improvements if you like (head studs, gen 3 oil pump, turbo upgrade, fuel rail, FP & injectors, etc). It will be as reliable as anything else depending on your skill level with engine work. Many of us track our cars and drive back and forth to the events.
BTW you can't really tune the stock ECU. Best to look at an aftermarket EMS and use that from the start. Will defintely help achieve your goals with room for further improvement.

Jim
 

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Discussion Starter #8
Once you start modifying the internals it really doesn't matter what revision 3sgte you start with. I'd be more inclined to remove and rebuild what you have including forged internals and cosmetic head gasket amoung other improvements if you like (head studs, gen 3 oil pump, turbo upgrade, fuel rail, FP & injectors, etc). It will be as reliable as anything else depending on your skill level with engine work. Many of us track our cars and drive back and forth to the events.
BTW you can't really tune the stock ECU. Best to look at an aftermarket EMS and use that from the start. Will defintely help achieve your goals with room for further improvement.

Jim
Thanks for the reply yeah the more I look the more it seems like just building a 3SGTE would be the way to go can you suggest pistons and rods and should I overbore to 87 mm? How about the crank can I use the stock crank I’m really trying to achieve like 450 wheel horsepower that’ll be more than fast enough for me
 

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Go watch Project Binky episode 30 (Well, watch the whole series). That'll give you an idea about how to build a 550 crank horsepower 3SGTE. Expect to spend 10k on parts and machining, 12 if you have someone else do all of the blueprinting and building.
You'll also need all of the supporting mods, especially for track use. Massive intercooler and radiator, oil cooling, and a trans cooler. It's also an amount of power that will be almost useless on a track unless you have a few years of experience. 180 crank hp on my AW11 is plenty to get into some serious code brown situations.
Properly done, you'll be in at least 20k before you have a track ready, 450whp SW, assuming you do all of the work yourself.
 

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Reading between the lines I'd guess the track running is a casual thing and nothing your going for to win any trophys. If your like many of us the goal would just be a good fun car to drive on road and do occasional friendly track events. For this build you would only need forged pistons and rods with no overboring required. The rest of the engine is quite capable of supporting 400whp but moreso you would want it to be responsive. Once you go beyond this is gets much more expensive, exponentially.

Apart from the increased power don't neglect the brakes and suspension. Spending some time and money on these will cut track times down more than the whp.
 

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It's also highly likely, I've found, that you are overestimating your power needs. I find that most owners I know personally, when they reach the ~300whp point, find that to be the perfect amount of power in the SW chassis. Maybe I'm wrong, because I don't know you personally, I've just seen this a few dozen times. Our car doesn't weigh 3500lbs like a lot of modern ~400whp cars. 300whp is a easily attainable goal on a healthy 3S-GTE with the right supporting mods. I'd just build what you have for what you need.
 

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It's also highly likely, I've found, that you are overestimating your power needs. I find that most owners I know personally, when they reach the ~300whp point, find that to be the perfect amount of power in the SW chassis. Maybe I'm wrong, because I don't know you personally, I've just seen this a few dozen times. Our car doesn't weigh 3500lbs like a lot of modern ~400whp cars. 300whp is a easily attainable goal on a healthy 3S-GTE with the right supporting mods. I'd just build what you have for what you need.
Mr Negative has some very positive points. These cars are light, sub 1300kg (2870lb) which is tiny vs most cars these days. Internet power figures vs actual real world cars are completely different. 300whp for these cars is getting up there for useable reliable power. Anything more needs quite a bit more money and work and then you start getting into turbos that have too much lag and you only have the large power for 1000rpm right at the top making the car terrible to drive everyday and not as fast as something that makes power for longer in the lower RPM. A fast street car has power down lower in the RPM and might not have the peak power but you put that against a car that makes peak power up top only and you will leave it for dead. On a track where the RPMs are normally higher, sure the car with peak power higher up might be faster but then it depends on the track too. Some tracks are tight and won't suit a car that has no low down power.

Reading between the lines I'd guess the track running is a casual thing and nothing your going for to win any trophys. If your like many of us the goal would just be a good fun car to drive on road and do occasional friendly track events. For this build you would only need forged pistons and rods with no overboring required. The rest of the engine is quite capable of supporting 400whp but moreso you would want it to be responsive. Once you go beyond this is gets much more expensive, exponentially.

Apart from the increased power don't neglect the brakes and suspension. Spending some time and money on these will cut track times down more than the whp.
These are also valid points.
 

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If a track car is your goal you really should consider the 2GR as well. Turbos on the track are trouble.
Is it really the turbo that's the problem? Or people either underbuilding the cooling system, cutting corners on plumbing, or some other workmanship issue? I feel like turbos just introduce more failure points, so it really highlights when someone has been a bit careless on the build or the has a line resting on the turbine housing, or has forgotten to tighten down a bolt or fitting etc.

Turbos do introduce more failure points, but I don't feel turbos are horrible for track usage. That was the common opinion in the 90's, but turbo tech was generally much less advanced than today, and most of the issues that were experienced back then could probably be mostly narrowed down to the open loop, primitive EFI systems of the time. Closed loop modern EFI stuff closes a lot of the risk of a turbo setup with GOOD hardware and GOOD installation methods.

I've tracked a lot of turbo and NA cars, and blown up lots of stuff on both. It almost seemed to kinda scale with the relative complexity and number of failure points, which does mean I had a few more exhaust sealing/fastener problems on turbos - even blew up a Garrett GT CHRA once. But I also blew up some NA engines over the years or blew head gaskets etc. Mostly it was pushing a factory setup a bit hard and not having enough cooling etc.

It's also highly likely, I've found, that you are overestimating your power needs. I find that most owners I know personally, when they reach the ~300whp point, find that to be the perfect amount of power in the SW chassis. Maybe I'm wrong, because I don't know you personally, I've just seen this a few dozen times. Our car doesn't weigh 3500lbs like a lot of modern ~400whp cars. 300whp is a easily attainable goal on a healthy 3S-GTE with the right supporting mods. I'd just build what you have for what you need.
Agree with this. A 400 rwhp 3S powered SW20 is going to be pretty rowdy, and definitely a more visceral experience than say a 400 rwhp stock C7 Corvette etc. You definitely wouldn't track a setup like that for more than a few laps at a time, as it'd be very tough to keep it cool for longer.
 

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Is it really the turbo that's the problem?
Yes and no. You are correct that with enough work a turbo car can be reliable on the track (mine actually was before the swap), but it's a lot more work to make it so. I spent years getting it to that point. Just more to go wrong. Not saying it can't be done, just harder. Probably the biggest challenge on the MR2 is getting enough of an intercooler into it. And if you don't, then you end up with heat soak issues where it's great for a couple laps and then power starts to fall off. My 2GR just works. My Turbo always kinda felt like it was on the ragged edge.

Beyond that, the power band, power linearity, and responsiveness make it so much easier to drive fast on the track.
 

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Yes and no. You are correct that with enough work a turbo car can be reliable on the track (mine actually was before the swap), but it's a lot more work to make it so. I spent years getting it to that point. Just more to go wrong. Not saying it can't be done, just harder. Probably the biggest challenge on the MR2 is getting enough of an intercooler into it. And if you don't, then you end up with heat soak issues where it's great for a couple laps and then power starts to fall off. My 2GR just works. My Turbo always kinda felt like it was on the ragged edge.

Beyond that, the power band, power linearity, and responsiveness make it so much easier to drive fast on the track.
True, and I largely agree with that. But I'd counter that an SW20 doesn't make the best dedicated track car by most logical measures. The chassis is not "super cheap" and readily available, parts are drying up, and it was mostly a one off vehicle with very little crossover to other vehicles. But we still love 'em and spend lots of time and effort on them.

I think the reason most NA engines are more reliable, is that people tend to do less shoddy modifications to them. There's only so much stuff you can touch, and a lot of that is defined by the factory. As in, replace the intake manifold, well, the interface flange and fasteners have been defined by lots of engineering hours and OEM validation testing. Do a completely custom turbo setup? Yea, once you're off the exhaust manifold flange, it's all custom/fabbed stuff, and most people do it poorly or just plain wrong.

Pre-turbo exhaust stuff is generally tough, and will punish you if you don't use the appropriate fasteners etc. - I'll give you that.

I hear you on the intercooler situation - but I think it speaks to just having good cooling. You could just as easily cook the oil taking a stock-ish car out with turned up boost on a hot day. The IC is a tougher one to solve, but that's what you've got to do to track something for extended periods of time.

I will counter that I don't think anybody is accusing a Porsche GT2 as not being a very reliable car to pound around on a racetrack. It's just engineering and attention to detail that separate a basketcase with a very reliable track car.

I too struggled with turbo engine reliability early on in my track years... until I figured out where I was being stupid and fixed that. After that, the thing was actually really reliable outside the cheap Garrett plastic bearing housing grenading.
 

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Water to air with a healthy radiator in the front is about the only way to get enough intercooling into an MR2 for track use. Reliability for a track car is relative. It's a car that will always need 10x more attention to maintenance than anything on the street, and will immediately punish you for not having your system up to snuff.

In any case, I'd wager that taking a 400+ whp SW20 onto a track without much experience is a way to do one (maybe two) or three things... 1: Not learn much because of being afraid of the car. 2: **** your pants when you spin the car because you hit a bunch of boost mid corner 3: Wreck a perfectly good SW20.
 

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Water to air with a healthy radiator in the front is about the only way to get enough intercooling into an MR2 for track use. Reliability for a track car is relative. It's a car that will always need 10x more attention to maintenance than anything on the street, and will immediately punish you for not having your system up to snuff.

In any case, I'd wager that taking a 400+ whp SW20 onto a track without much experience is a way to do one (maybe two) or three things... 1: Not learn much because of being afraid of the car. 2: **** your pants when you spin the car because you hit a bunch of boost mid corner 3: Wreck a perfectly good SW20.
Agreed. My S13 240SX was a downright handful on sticky street tires, no aero downforce and ~320 rwhp (~2500 lbs with a full gas tank). Adding R-comps and aero calmed it down quite a bit, to the point that it started becoming a bit more like a momentum car which was a fun change of pace (granted a momentum car that could lap with a modded C6 Z06). But that's coming from someone with thousands of laps under their belt.

I find most new drivers are absolutely unprepared for driving a car with little to no driver aids fast on track. No ABS, no traction control etc - it's a steep learning curve - but it'll also make you a better driver. That was the norm 20+ years ago, as very few cars people were tracking were fancy enough to have that stuff so you learned to drive the car yourself. I've been more than a little thankful for sophisticated driver aids in modern cars while sitting in the passenger seat instructing on track, but it really does keep the driver from learning. I've even had lots of drivers swear up and down that what they were doing was fine, as the car didn't "feel bad." They were just used to the computer sorting things out with wrong steering/brake/throttle inputs when nearing the limit, so that felt natural. I guess it's like being accustomed to overly compressed MP3s and streaming radio when that's what you grew up listening to vs. cassettes and CDs...

Enough old man rant - OP - pick whatever engine makes you happy and ticks all the boxes. But I'd definitely say if you're not really experienced behind the wheel, don't figure you need more than 250-300 rwhp to have lots of fun with an SW20 on track. In fact, 300 rwhp driven in anger would likely scare 99.999% of the people on this forum.
 

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I will counter that I don't think anybody is accusing a Porsche GT2 as not being a very reliable car to pound around on a racetrack. It's just engineering and attention to detail that separate a basketcase with a very reliable track car.

I too struggled with turbo engine reliability early on in my track years... until I figured out where I was being stupid and fixed that. After that, the thing was actually really reliable outside the cheap Garrett plastic bearing housing grenading.
And there in lies the problem.
For engineering nerds like you and me, attacking the idea of a turbo track car as a problem to solve can be fun, challenging, and rewarding.
For the average car enthusiast, it's just going to be expensive, frustrating, and demoralizing.

That's why if someone says they want a motor suggestion for a track car, I will say 2GR 99% of the time. That and, as you and others have said, 300whp is really plenty of power for a track car unless you REALLY know what you are doing.
 

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And there in lies the problem.
For engineering nerds like you and me, attacking the idea of a turbo track car as a problem to solve can be fun, challenging, and rewarding.
For the average car enthusiast, it's just going to be expensive, frustrating, and demoralizing.

That's why if someone says they want a motor suggestion for a track car, I will say 2GR 99% of the time. That and, as you and others have said, 300whp is really plenty of power for a track car unless you REALLY know what you are doing.
I wonder how many of us are actually engineers? :ROFLMAO:
 
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