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Help! Car dont wanna make Power...

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Evo-Jr

15+ Year Contributor
121
2
Mar 23, 2006
brooklyn, New_York
Hey guys. After going crazy and spending so much money trying to built this new set up, now the car is not doing what it suppose to do. I dont wanna lip up the car on fire :cry:

This is what i have:
2.3 Stroker, Wiseco 9:1 piston,0.20 Manley I beam,Eagle 100mm crankshaft,Kiggle main girdle,ACL bearings, Fluidampr Damper, Bshaft remove,ARP head studs,3 angle valve job,Custom sheet metal intake manifold,SI dual springs and retainers,SI nitride valves,272/264 HKS,T4 tubular manifold, Precision turbo billet wheel 6268,ACT 6 puck,ACT 2900 pressure plate,Fidanza flywheel,AEM wideband,3" downpipe,FIC bluemax 1450,Walbro pump in tank and bosh 044 inline,MAF, DSM link v3 full..

Took the car to get tuned at a shop in PA, the guys at the shop work all day trying to figured out the problem.. The car only made 433 and 343 torque.. For some reason the car wasnt making boost, only about 23psi on C16.. They though it was the wastegate or the boost controller, they swap both with parts from the shop and nothing. After swapping the parts they gaved it another try and then they said the clutch was slipping which it cant be possible because is brand new, then they said it might be the cams or that my turbo is holding back! 6262sp journal bearing T4 .68 v-band...

Really dont know what to do at this point :banghead: I dont wanna go and spend money that i dont really have on parts that i might not need.. Can someone please help out on this one, im clueless :confused:

Please guys, very confused....
 
  1. How new is the clutch?
  2. Do you have a catalytic converter?
  3. Did you try removing the vacuum line from the wastegate completely (capping the other end off) and seeing how much boost you could build?
  4. What type of MAF are you using?

:dsm:
 
The clutch has about 500 miles, install everything new.. We try everything with the wastegate and noting.. At one point we found a small leak by throttle body and fixed and the car made another 2 psi, but no power gain.. I dont have a catalytic converter, straight 3 inch with a flex.. Im using the 3"gm maf, with the gm maf cable from DSM Link...
 
the clutch has about 500 miles, install everything new.. We try everything with the wastegate and noting.. At one point we found a small leak by throttle body and fixed and the car made another 2 psi, but no power gain.. I dont have a catalytic converter, straight 3 inch with a flex.. Im using the 3"gm maf, with the gm maf cable from dsm link...

ive seen some ebay flex couplers colapse and not make power... And boost..
 
I was going to say try dropping the DP, for testing purposes, to see if you can build more boost. A good friend and tuner were stumped when a DSM running an FP RED could only build 18psi with the wastegate completely disconnected. It was a collapsed catalytic converter creating a restriction in the exhaust which seems to be the case with your setup as well. Its really the only thing that makes since unless you've got a pre-turbo exhaust leak somewhere or your BOV is opening at 23psi and regulating boost on its own. Have you checked the BOV too?

:dsm:
 
I was going to say try dropping the DP, for testing purposes, to see if you can build more boost. A good friend and tuner were stumped when a DSM running an FP RED could only build 18psi with the wastegate completely disconnected. It was a collapsed catalytic converter creating a restriction in the exhaust which seems to be the case with your setup as well. Its really the only thing that makes since unless you've got a pre-turbo exhaust leak somewhere or your BOV is opening at 23psi and regulating boost on its own. Have you checked the BOV too?

:dsm:

We try that to, took off the downpipe and even check the flex and everything was fine.. Now the blow off valve was never check, as mad of fact. They relocate my blow off valve because it was on the wrong place according to them.. They put it right by the intercooler, and that I think about it could it be because now is facing tours the floor? Maybe is not opening because the air from the fan that they use to cool off the car? Just saying, don't know!

ive seen some ebay flex couplers colapse and not make power... And boost..

LOL is not an ebay flex pipe, is the turbo one from Vibrant :thumb: only good parts go on my car.. For nothing anyways because is not making power :ohdamn:
 
Do a BLT up to 30psi and watch the bov, see if its opening or not.

:dsm:

Going to try that! Since you mention the BOV a few times, i keep thinking that it could be it... I never seeing a BOV install the way they did my, is right by the IC facing the floor.. I could be wrong, i really dont know much about this things :nono:
 
I know you've got a new clutch but what kind is it? Not saying you went for a cheapy but I've had new clutches slip on me before because I gave the clutch a little to much credit for being able to handle a load....I turbocharged a 90' Mazda Miata with a 1.6....it made 94rear wheel hp stock and on a t25 set to 13psi with a front mount and a few other mods it made 178 rear wheel at 5200rpm before a brand new Weighted CenterForce Dual Friction clutch started slipping on the dyno.......Had to swap to a 1.8liter flywheel and an ACT clutch and back to the dyno with no other changes yielded 203 rear wheel and just over 190lbs ft of torque......sure she's not slipping on the dyno?........you can typically hear the engine run away from the the wheel speed when you watch the dyno runs.....
 
I know you've got a new clutch but what kind is it? Not saying you went for a cheapy but I've had new clutches slip on me before because I gave the clutch a little to much credit for being able to handle a load....I turbocharged a 90' Mazda Miata with a 1.6....it made 94rear wheel hp stock and on a t25 set to 13psi with a front mount and a few other mods it made 178 rear wheel at 5200rpm before a brand new Weighted CenterForce Dual Friction clutch started slipping on the dyno.......Had to swap to a 1.8liter flywheel and an ACT clutch and back to the dyno with no other changes yielded 203 rear wheel and just over 190lbs ft of torque......sure she's not slipping on the dyno?........you can typically hear the engine run away from the the wheel speed when you watch the dyno runs.....

The clutch is an act 6 puck, act pressure plate n fidanza flywheel... We know for sure it wasn't slipping on the dyno because we were on top of the car to make sure it didnt slip.. Really don't know what's going on with this car, very upset.. After spending close to 8k, and this car no performing the way it suppose to! Not cool at all
 
I noticed you have a .68 housing....is that the hot side? have you tried going to a slightly more relaxed hot housing to reduce the back pressure the system can develop due to hot side a/r?
Try going to a .73 or a .82.......it'll be a little more laggy but peak power will be higher because the housing will flow better......I have a car I'm building for a friend with a PE6262 (dual ball bearing) and we are using a much larger housing than .68 so we can get close to the flow capability of the turbo (700hp)
have you tried swapping housings? cause the rest of your set up sounds like its bad-ass.....
 
I noticed you have a .68 housing....is that the hot side? have you tried going to a slightly more relaxed hot housing to reduce the back pressure the system can develop due to hot side a/r?
Try going to a .73 or a .82.......it'll be a little more laggy but peak power will be higher because the housing will flow better......I have a car I'm building for a friend with a PE6262 (dual ball bearing) and we are using a much larger housing than .68 so we can get close to the flow capability of the turbo (700hp)
have you tried swapping housings? cause the rest of your set up sounds like its bad-ass.....

Hey thanks for the complainment! I'm sure this car could make crazy HP.. A friend also told me about the hot side, yes my hot side a/r is 68... I was told to try 82 a/r but I don't know where to get it from! I would need a t4 82 a/r with a v-band hot side, that's what i have now.. If anyone could tell me where to get it from? And which one should i buy? it would be a nice father day gift :) Thanks a lot
 
Last edited:
Yea I'm pretty confident that swapping out your hot housing could fix the boost issue....a .68 should give you great mid range torque and with 9.0:1 comp you could get that thing spooled pretty quick considering its size but unless your only wanting about 375-400hp your gonna choke off the engines ability to breath....
Is it climbing up really quick at first then kind of dragging itself up to 7500? Cause if your spinning the engine up to 8k I can see this thing pulling strong up to 6k-6500 and then dragging itself up to the upper limit.....
 
Yea I'm pretty confident that swapping out your hot housing could fix the boost issue....a .68 should give you great mid range torque and with 9.0:1 comp you could get that thing spooled pretty quick considering its size but unless your only wanting about 375-400hp your gonna choke off the engines ability to breath....
Is it climbing up really quick at first then kind of dragging itself up to 7500? Cause if your spinning the engine up to 8k I can see this thing pulling strong up to 6k-6500 and then dragging itself up to the upper limit.....

Yep, I'm going to try swapping to a bigger hot side, but they only make 81a/r for my t4... I'm confused on which one to order because they have different size Trim! Can any one tell me which one would work on my turbo?
 
Posted right off of Garrett's website, I figured I'd copy paste rather than trying to word it differently. Changing the A/R of your hotside is only going to effect turbo responsiveness and airflow, neither having to do with the amount of boost you can run. Switching to a bigger hotside is going to make your car feel like a turd, especially since you can only run 23psi.

Garrett said:
Turbine A/R - Turbine performance is greatly affected by changing the A/R of the housing, as it is used to adjust the flow capacity of the turbine. Using a smaller A/R will increase the exhaust gas velocity into the turbine wheel. This provides increased turbine power at lower engine speeds, resulting in a quicker boost rise. However, a small A/R also causes the flow to enter the wheel more tangentially, which reduces the ultimate flow capacity of the turbine wheel. This will tend to increase exhaust backpressure and hence reduce the engine's ability to "breathe" effectively at high RPM, adversely affecting peak engine power.

Conversely, using a larger A/R will lower exhaust gas velocity, and delay boost rise. The flow in a larger A/R housing enters the wheel in a more radial fashion, increasing the wheel's effective flow capacity, resulting in lower backpressure and better power at higher engine speeds.

When deciding between A/R options, be realistic with the intended vehicle use and use the A/R to bias the performance toward the desired powerband characteristic.

Here's a simplistic look at comparing turbine housing geometry with different applications. By comparing different turbine housing A/R, it is often possible to determine the intended use of the system.

:dsm:
 
Isn't flow capability somewhat relative to turbine speed? If your turbo's flow capabilities restrict the engine's ability to produce the additional volume needed to effect turbine speed, (since boost thresh hold is set about by a combination of flow,velocity and heat) why would it not make more boost if the hot housing is too close in relation to the turbine itself?

Like if you put your thumb over a water hose at a given rate of flow of course you can make the water come out at a higher velocity, but if you release your thumb slightly the water velocity is reduced until flow rate is increased to cause the same effect..
in this case the engine would represent the water and the turbo would represent the thumb...
A larger hot housing should allow for full flow potential of the engine to be exerted...with extra flow on hand you should get more flow overall, which in turn will create more power and would allow for the engine to create more boost (albiet later in the power band)

or am I missing something?

it kind of sounds like Garrett is saying the same thing take a look.....

This provides increased turbine power at lower engine speeds, resulting in a quicker boost rise. However, a small A/R also causes the flow to enter the wheel more tangentially, which reduces the ultimate flow capacity of the turbine wheel. This will tend to increase exhaust backpressure and hence reduce the engine's ability to "breathe" effectively at high RPM, adversely affecting peak engine power.

Conversely, using a larger A/R will lower exhaust gas velocity, and delay boost rise. The flow in a larger A/R housing enters the wheel in a more radial fashion, increasing the wheel's effective flow capacity, resulting in lower backpressure and better power at higher engine speeds.


If the engine is outflowing the turbine then the turbine will not spin faster but rather hinder the engines ability to create higher exhaust flow.....since the engine cant produce the higher flow rates this limits turbine speed ....

if they switched waste gates and the car still only makes 23psi and the exhaust is proper with low restriction what else could limit boost pressure other than engine flow being effected by poor cam timing or bad ignition timing (barring a faulty boost controller)

I'm not being an ass by the way I just don't want to be giving poor advice to someone if I am mistaken about the way A/R effects pressure and flow....
 
There's no way you're outflowing a T4-flanged 6262 with your setup.

You have to be experiencing some sort of wastegate issue- any idea what spring(s) were in the gates you were using? If it's a 7psi spring, there's your problem.
 
I could totally see a spring causing that......whats the most you've seen a T4 flanged 6262 with .68 housing on it? just curious..... I've seen problems with out flowing .68 housings before but that was also on a T3 housing.....I over looked the fact he was running a T4 housing....
 
I called precision today to find out which turbine housing would work, he told me there's no way i need a bigger housing.. A t4 flange with a 68a/r is way bigger then the t3 with 68a/r.. In other worlds i dont need to go bigger... The problem is some where else, im going to check the spring on the wastegate.. But then even when the shop put a tial 44 wastegate the car didnt make a different :hmm: so dont even know if i should take my apart.. I have the old turbonetics delat gate, that thing is great.. For some reason i wanna believe that it might be the cams and springs like a few people had told me, but i also seeing people here on the forum with little upgrate on cams and they making way more power then i did :cry: That is sad! I dont wanna spend $1000 dollars in cams and springs and then that wont even fix the problem :banghead:
 
I called precision today to find out which turbine housing would work, he told me there's no way i need a bigger housing.. A t4 flange with a 68a/r is way bigger then the t3 with 68a/r.. In other worlds i dont need to go bigger... The problem is some where else, im going to check the spring on the wastegate.. But then even when the shop put a tial 44 wastegate the car didnt make a different :hmm: so dont even know if i should take my apart.. I have the old turbonetics delat gate, that thing is great.. For some reason i wanna believe that it might be the cams and springs like a few people had told me, but i also seeing people here on the forum with little upgrate on cams and they making way more power then i did :cry: That is sad! I dont wanna spend $1000 dollars in cams and springs and then that wont even fix the problem :banghead:

Ive been having boost issues for a long time and have tried just about everything
Proof: http://www.dsmtuners.com/forums/hangout/335300-somthing-isnt-meshing-right-my-car.html
Another: http://www.dsmtuners.com/forums/turbo-system-tech/404680-slow-spool-bad-boost-recovery.html

Maybe those can give you a few more ideas that might work for your problem. I just bought the FP beehive/retainer kit and I'm picking up another set of FP2's this weekend. We wont be putting them in till the 18th though if you can wait for the results it might save you some money. The new theory with my problem is that I have a messed up set of cams that would need to be dagreed to work and that I may have valve float...so once again I'm throwing money at the problem since we cant find it. I really hope one of the things I've tried solves your problem so you dont fight this thing for 2 yrs like me.

What are your compression numbers? One of the reasons the local guys think its my cams is because my compression is so low (145 on a built motor with less than 3k on it and most of that was properly breaking in the new TRE Tranny). They think the cams are opening the valves at the wrong time releasing the pressure in the cylinders. My leakdown test was good also.
 
Have you done a compression test? I know its a new engine, but you never know.
 
But then even when the shop put a tial 44 wastegate the car didnt make a different :hmm: so dont even know if i should take my apart..
Consider the possibility that their gate could have also contained a 7psi spring. :hmm:

You need to at least remove the cover and see what spring setup your gate contains. If it's too light, there's no way you're going to achieve consistent boost above 20psi.
 
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