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New Turbo kit wastegate problems, laggy..

7K views 78 replies 7 participants last post by  tksmr2 
#1 · (Edited)
Hello,

I have have PTE dbb 5858 turbo kit from RacerX on my 93T with the following

Greddy Pex with KO racing 3" bpipe
Walbro 255
CRW axle cages
Berk SMIC
Tial MVS
Top mount manifold-vband
3" downpipe, re-routed..
NO MBC ( I do have a TurboXS MBC, but have to run just on wastegate for now, so mbc is out of the equation)

I had it all put on and then took it for a test drive. It's really super laggy and if I floor it I can get into boost, but it's real laggy and only gets to about 3psi.

So, I tore everything back apart to make sure I didn't leave anything like a rag in the ports in the head to manifold, intake manifold , or intercooler piping. I ran compressed air through the exhaust manifold and everything seems fine.

Put it back together, and of course I'm still having problems. Thinking maybe I messed up the diaphram when I put the springs in and it pinched.. possibly?? I should have checked that, but didn't.


I ran compressed air to the wastegate port and the valve is working fine. I ran compressed air to it on the car, working fine. The fire ring is indeed installed 100% for sure as I checked that too.


I also re ran the vacuum line several different ways to the MV-S and nothing changed. I also put a block off screw at the top side port of the wastegate and that didn't help either. I have the top port vented just like the instructions say. I'm at a loss, so I'm seeking help on here. Thanks!




This line is going to the 'air' port on the side of my wastegate.




Shows the connection at my 'air' port from that 5/16" hose that is show in the pic above. I have a metal vac line connecting the 5/16" hose to the metal line to the vac line leading to the waste gate.




pic showing the vac line off the stock intake manifold to the stock BPV.




I also ran the vac line from the intake manifold straight to the wastegate, and that didn't help. I ran the vac lines in several other configurations, and nothing helped. So, I either got some mystery item stuck in my piping somewhere, the wastegate is faulty or I have the vac lines somehow hooked up wrong. But, how do I know for sure the wastegate is faulty other than buying another one?



Thanks!!
 
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#44 · (Edited)
Actually there is a leak. I just didn't drive the car enough for it to start dripping to the ground. It's very small leak at my return line on the oil pan fitting.. I tell you what.. I'm sick and tired of trying to get that sealed up. I'm going to try and torque the two 12mm nuts down a bit more to see if I can get it to stop leaking. If not.. ...

I'm off to Toyota tomorrow to get Fipg b/c Right STuff an other junk I've tried just isn't working out.

I know it's best to remove the oil pan and just have that dang thing welded on, but knowing my luck I could never get the pan to seal up if I did that.

Funny thing is that super thin metal gasket on the GEN3 hose fitting for the return line sealed up fine, but RTV won't do crap to seal that thing. Maybe I should just buy another Return line gasket, or try and reuse the old GEN3 one.. but I doubt that will work.


On a side note... I'm boosting again. That red hose worked out with the Tbolt clamps. But, knowing my luck... something else bad will happen tomorrow.. I think I'm done doing big jobs like this on my car after this.. I should just stay away from working on it other than general stuff.
 
#45 ·
Just starting to get used to the new power band. Drove the car at night last night about 30 minutes away from home, and it made the round trip.

Just seems as though it's a bit harder to get into the sweet spot b/c of the lag. But, once I get to it, the car actually feels a bit faster than what I remember it being with the CT20b.

Now, I'm more anxious to get rid of this SMIC, and get a re-plunum and EMS, Cams, fuel.
 
#48 ·
Yea.. but what's the point in having an EMS when you are below 300whp with CT20b?

It's not like I"m the first person to slap an aftermarket turbo on a GEN3 without a tune. Just running at lower boost. As long as my AFR's are under 12.
 
#51 ·
better safe than sorry is the way of thinking. he got a 5858 so his goals are higher than 450. thats why people have build plans

Set your goal, then get the necessary components, starting with the safest first. I have the map for the 5858cea and i can tell you, it does push much more cfm above 17psi than a ct20b at the same boost levels.
 
#52 ·
Turbo's do NOT "push" CFM, they incease the density of the air by increasing the pressure. CFM is 100% dictated by the engine and and exhaust flow restriction (i.e., the VE of the engine). No matter what turbo you put on a car (assuming that the compressor is "big Enough" for the job), if an engine flows say 190CFM, then it will flow 190CFM. Again, MFR (Mass flow rate) is where power comes from and MFR is the density increase (which density is a product of temperature, pressure and humidity and nothing more) times the volumetric flow rate. So whether you run a CT20b or a 5858, at XXpsi and XXXcfm, the MFR will be virtually the same and thus the power will be virtually the same.

As I said before, its just a matter of the 5858 having more "potential" then the ct20b but other then the increase if VE from the increase in flow from the bigger turbine of the 5858, the power at a give PSI will be the same. Now once you surpass a give MFR that the turbo is "capable" of, then the the "real" difference is seen.


All in all just cause a turbo "can" move xx (or xxx) lb/min doesn't mean that its going to on a particular engine. The engine is what ultimately dictates what it will flow based on what the engine will except at XXpsi of boost.
 
#53 ·
Thanks fellas.

My goals are actually 400whp on 93 and 475whp on E85.. That might be pushing it a bit on the stock bottom end though, so I may back off a little. And, this is all taking into account that I'll have the supporting mods for this, of course.

I think I'll be fine with the little bit of lag. I'm just not used to it yet. Just have to put a little more effort into driving the car harder to keep the RPM ranges up, as before I was used to babying it, and still getting some spool in the lower RPM range, even if I got caught in too high of a gear, it would still spool a bit.

Long term goals may be a built motor, but at this point, things have changed, and I don't see that happening. I've actually been swayed away from built motors, and would rather not go down that route.

I know the turbo is slightly over-sized for my goals, but it's what I have, and I decided to put it on b/c everyone told me at the time it would be a good choice based off everyone that used the 5857.

Worst case is that I can slap on a slightly smaller turbo to my vband manifold and use that instead.
 
#54 ·
The 5858 is not a bad choice for those goals, just not the best. You could make those goals on a GT3071/S252 with faster spool. The 5858 really comes into it's own at 500whp+.
 
#57 ·
Texas,

Yes.. I figure If I get to the point were I just don't like the spool, and never surpass the 500whp mark, then I can consider the GT3071/S252 or whatever is better at that time. I'll just sell the 5858 to someone that is looking for more power.
 
#60 ·
He is spot on, many people think bigger is better when it isn't. Intake manifolds and particularly porting the head are 2 good examples.

They always think that bigger is better and open it up but in reality you often want to actually make the ports smaller (unless going for very high power that is naturally).

The old one makes the ports smaller for a good portion of his builds and makes record setting power out of basically everything he does.

It seems so backwards but it works. Velocity > Flow in the priority of things.

It is not tuned yet right? Also are the cams degreed? Both of those can have a big impact on spool.
 
#62 ·
The cams I have are not installed yet. I'm waiting to get the EMS before the cams are installed. So, stock ECU and stock cams now..

Gen 3 S1 Cams

Intake - 268 Duration 10.5mm Peak Lift
Exhaust - 268 Duration 10.2mm Peak Lift
 
#64 ·
So, by me not having a tune and the stock cams, is at least part of the reason the lag is so lousy right now. but, I don't know what to compare this to b/c I've only owned small turbos, and superchargers before. So, all of that stuff spooled super fast, where this setup has zero power down low until you get into boost..

Again, I knew this setup was not ideal, but I have a fairly limited cash flow like a lot of people. I will get to my desired goal.. but will just take me longer. :)
 
#65 ·
The cams might help spool they might not. They will for sure give you more power though and that will make the power band much more enjoyable.

The tune should help spool some and power as well.
 
#66 · (Edited)
Ok my tial mvs gate is still not working . I overboosted tonight to 18.4 psi. I can run a quick burst of compressed air to the gate and can clearly hear the valve functioning. I dont have any vac leaks .. the valve ring is installed. Not sure what is going on but car is sitting until i figure it out.

I took off the vac hose from the compressor housing and put air to it and can hear the valve inside functioning.



 
#71 ·
The springs rating doesn't seem to matter much. A few guys on here had overboost issues but when they tested the wastegate found that the springs were actually not allowing it to open until higher then rated pressure. The wastegate was actually working perfectly all along.

They lowered the springs and the boost dropped.

In other words I would try testing what the actual opening pressure of the wastegate is before you chase phantom issues.
 
#72 ·
Seems that thats a lot though (11.x to 18.x) seem like a lot for the springs to be off. A couple psi at best I could understand but 7?.... If that is the case, thats pretty poor quality on Tial's part. Maybe that's why I've always like the few different Turbosmart gates I've used over the years. All of them were pretty much dead on with controlling boost (i.e., a 14psi spring configuration controlled boost to dead on 14psi (+/- a point or two)).

I do agree though, it wouldn't hurt to actually check the wastegate function pressures with a small pressure supply (like a bicycle pump) or even a compressor with an pressure regulator that will go down to a few psi.

OP, Just dont be alarmed if and when you test it to find some leaking around the valve stem. This is normal but it should be very minor / little though. There is no seal on the stem of the valve where it goes up in to the diaphragm housing and they have to expansion clearance between the stem and the guide so they will leak a little around the stem.
 
#73 ·
IIRC Josh was using a ~15-17psi spring combo but was getting ~28-30psi of boost. So it would not be the first time.

I think it has more to do with mislabeling then part quality personally. It also seems to effect dual springs more then singles.
 
#75 · (Edited)
Thanks Everyone!


So, If I hook up my compressor inline with a pressure regulator, set to 10, 11, 12psi, or set it really low, and gradually raise the pressure until it functions, then I know were my spring pressure is on my gate, right?

Okay, it seems like I'll have to experiment with some of the lower boost springs.

I'm kind of fed up with it b/c it's no easy task to remove that gate, and I'm pretty sure I stripped one of allen heads last time I was tightening it down in a super small space were I had to use a 2 ft extension.

Anyway, I'm going to call Tial and talk to them. I'm pretty certain it's got to be the springs, even thought what I have in there now certainly should not be boosting 18.4 psi.. Heck it might go a bit higher that that, but I haven't held the car at peak boost yet, and won't until I get this sorted out.

On a side note.. I didn't have my clevis adjusted correctly ,and thought I hit fuel cut last week when I miss shifted b/c I had my release point on my clutch up way too high... So, that would make sense. I didn't check peak boost on my gauge after that boost hit, but I thought I saw 18 sometime that night as well.

Live and learn I guess. I thought the springs were pretty accurate from what I read online, but again.. I should have known better to believe much of anything from an on-line search.
 
#77 ·
I'm going to put either the yellow or red spring in next time. It'll hopefully cut off boost before 12psi, and then if it's too low, I can always hook up my MBC to raise it if I desire to do so.


Yellow spring is 7.25 psi.
 
#79 ·
Few problems.


Need to change out the wastegate spring ,so I putted around this weekend only boosting to about 5 or 6psi at most.

Anyway, my car is now chugging at low rpms/very light throttle b/t 1,500 to 3,500rpm. If I'm boosting it seems perfectly fine.

I do have a fluttering sound/exhaust leak at my hotside were the downpipe connects via a v-band connection. I tried numerous times to get that thing to seal up, but still having issues, so going to put a Vband gasket on it. But, could a exhaust leak like that cause the chugging issues? I was told that it was my knock sensor and pulling timing.

My ignition components are all good/newer.

My next step is to get meth kit on this, and run really low boost off the wastegate until I get an EMS for this thing and put the 1,100 ID's in.

The car scares me now being the way it is. The chugging at low RPMS.. I'm thinking is the O2 sensor getting bad readings.. thus causing the problem at low rpms.. but I'm not 100% sure that's the case until I can get the exhuast sealed up in that spot.
 
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