Ok the set-up
1988 10th AE
1993 rotors with streetported motor.
T04B 60-1 .96 .70trim 4"inlet. Undivided set up, 42mm racegate wastegate.
HKS cast manifold full 3" exhuast single
550/1600's walbro 255 parrallel fuel system.
Tuned by steve kan.

Problem:
No boost response. Turbo will not produce full boost below 5000-5500rpm?

On the printout I hit 408.8rwhp and 304.6 torque at 7200rpm The torque and hp intersect's at 5300rpm.
I only produce 140rwhp at 4000rpm. No matter what we did nothing would increase the boost response. I even took the boost line to the wastegate off to see if it would respond anybetter. Nothing.


Also turbo makes no difference if I run 15psi or 19psi. Same max power.


Any ideas.

I know its not supposed to respond like stock but this is awful. The only thing this does is pull nice top end.

 

Ok here is a word doc of the file.

My friends KKK turbo which is way bigger then mine on the same dyno partially tuned pulls more torgue/hp and produces boost way earlier?

 

And we're all waiting on the turbine A/R...?


-Ted

 

how is your air fuel ratio around 4000? perhaps your secondary injectors are not staging properly. i would think that steve kan would have that figured...

who built the turbo? perhaps the clearance between the compressor wheel and the housing is too loose causing cavitation. you do have good peak hp. mid range does suck however.

howard coleman

 

I figured for the people that could answer the question the T04B 60-1 .96 .70
would mean .96A/R .70 trim.

Sorry.

 

I think the A/F is 11 or 12s all the way through. I could be wrong I thought steve told me 11's. It was a busy tuning day and I'm sure a few things slipped by me. The secondarys cannot be felt. Nice tune for cruising. The staging is set at bar 12.


Turbo is from Turbonetics. Brand new. The wheels spun by hand but seemed to be a little stiff like when I spun it by hand it only spun for a second. I am going to take the air intake off soon to check it again.

Yup the top end is nice but I really need to fix that bottom end

It was suggested to me that it might be the magniflow silencer/resonator/muffler thing would be a restrictor for spool up.

 

Wastegate vent to air or back in to exhaust? Reason I ask is when (if you can) hear the wastegate open? Make sure it's closed before you start. Wondering if it's paritally open at low boost. Could the flange or gasket interfering.

Might want to disconnect the silencer at the mid-pipe and see if back pressue/something clogged down stream of the DP.

Edit: And my favorite reason, a leaking BOV. Spring not strong enough to resist the boost.

 

Good points thanks.
-Vented to exhaust
-Steve Kan said WG was opening. I myself did not hear it or do not know what to hear
-once I get some money I will remove the mid-pipe (resonator thing?) and see if that makes a dif.
-I tighten the BOV even more. This was one of the first things that was done

O ya this is going throught the Greddy V-spl FMIC but I don't think that should be an issue.

Thanks.

 

What's the ignition timing at those points?



-Ted

 

WG stuck partially open?

 

This is a long shot...
What's the compression numbers on the engine?


-Ted

 

PM me your email and I will send you a snapshot of it since I do not know how to post it.

Its around 32deg @ 2500rpm and up until bar11 and 30deg @ bar 12, 28deg @ bar 12.

At 2000 around 12 to 16 then 22degs.

Its really different to how I had the car before.

 

No idea. New motor by a good builder. I could check that in a few days only.

 

Would not know? How can you tell? Its a 10psi spring since thats what the car builds with boost controller off.

Its a new WG as well.

 

I had a similiar problem, turned out to be a restricted muffler. Just for fun try dropping the exhaust after the dp and give it a quick run. P.S. will sound like a top fueler.

mike

 

Straight through muffler.

There is a silencer magnaflow muffler in the downpipe?

Anyhow I can't imagine it being any louder. It cleared out the dyno shop

 

It was just a thought. It doesnt sound like its in your tuning, just another idea is your throttle plat opening all the way.

 

dp

 

I think so. If not I would think it would suffer from high end no?

Down pipe is nice and mandrel bent. Don't think the issue is there. 3" DP.

I'm beginning to think I might have wrong spring in it. It would be nice if that was the case but I have the silver spring from turbonetics which should be 10psi spring.

I was looking at the wastegate and the shaft has a washer. This is sitting in the middle of the shaft???

 

Ok. I pulled the air intake off and spun the turbine blade by hand. At first it was sticky. After which it spun freely.

when I push on the shaft and spin it it binds and is harder to spin. there is really nothing for shaft movement.

Its almost like if the exhaust housing is in boost it might be binding the wheel?

Also the turbonetics deltagate racegate Wastegate has a washer on the shaft. this is in the middle of the shaft. Is this normal.

Also for a 42mm it seems to spike enough......

 

Ian, I doubt very much its your WG spring. I was running a 14.5 spring, and my response was better than yours even at a measly 10-12 psi.

Then again, I do have an undivided turbine and manifold...

Also, correct me if I'm wrong, but wouldn't a WG spring that is closer to your target boost, allow you to make boost quicker and hold boost better?

 

target for the street is 10psi. Drag etc 15+.

I think it is the WG spring not full closing since when I popped it off it looked to be out. I still could push it in with my finger.

We will see when I take her for a spin again.....

 

Hmmm. Well get it figured out. 10 and 15 eh?
I will be running 14.5 to 18 until the engine lets go

I'm working on a few things suggested to me by Chris Ng to fix my ignition problem...I'll keep you updated.

 

Does the wastegate have a separate valve seat (looks like flange or a ring)? Make sure the valve is pressed into the seat (to close the wastegate flow path) when everything is bolted together. You can take the wastegate off and see if it looks like the valve is holding shut (valve marks on seat? or all carbon?). You can put the valve and the seat together and make sure that the valve will actually touch the seat when things are together. There are a fair number of questions on here about the order in which the wastegate valve, seat, gasket, and flange go together, so it might just be that yours is not assembled correctly.

EDIT: I went and looked at a picture of the wastegate on turbonetics.com. it looks like the valve seats against the body of the housing, so it is probably not just an assembly error. However, I am still curious -- if you remove the wastegate from the car, is it clear that the valve can close by being pressed into a valve seat (either built into the WG housing or a separate piece)?

-Max

 

Well called Turbonetics after a compression check and looking at my vacuum gauge. Figured if it pulls the same vacuum as stock set up it should be fine.

Compression was around 85 to 95psi! Even bounces as far as I could tell.

Anyhow I told Turbonetics that by me pushing on the turbine wheel it feels like its binding.

They told me I cooked the turbo! Done. Kaput. 900km on a full turbo system.

Anyhow car is going away!!!!!!!!!!!!!!!!!!! For some time! I can't assume its any good driving around like this. I quit!

Maybe my oils lines were no good??