Dyno numbers don't mean anything. Take your car to the track and calculate your hp from your ET and MPH. You should probably be able to hit 11.3-11.5 with your setup, depending on weight or given that is stock weight.

 

But do you KNOW that you don't have one? If you're using an MBC, then that is a terrible torque curve for a 3076. On racegas @ 28psi that torque curve should be virtually flat all the way to redline ... maybe a small taper towards the end. My suspicions:

1.) Boost leak - pressure test the whole system to 30-35psi
2.) Tuner doesn't know what he is doing - is this being tuned with stock ECU?
3.) eBay IC is getting heat soaked - look at Buschur's IC numbers on his website if you want proof

Most likely a combination of (1) and (2), with (3) thrown into the mix.

l8r)

 

Also, what are your wideband AFR's at WOT?

 

Seems off.

Scorke

 

its hard to say because the graph doesnt have a reference, but it looks as though your boost has dropped down to around 24-25 psi by redline. this would account for your torque dropoff in the higher rev's. right where this turbo would shine above a stocker, locate your source of boost taper & you will find your lost/missing power.

nobody "thinks" they have a boost leak, they can be silent & unnoticeable, even more so on a properly set up OEM ECU as they are quite good at corrections on the fly

a good way to spot a boost leak if you have a laptop but dont have access to a boost leak tester is to watch your short term fuel trims. at idle the values will go positive as the vacum sucks in unmetered air & the computer compensates........ the trims will go negative as you enter boost & the metered air escapes


another possibility, though unlikely is that your HAFE manifold setup did not get cleaned up prior to install. did you do the install yourself? did you port match the transitions? (primarily manifold-turbo, & o2-collector area) while the HAFE setup is very nice, the cleanup on their castings leaves something to be desired. when i got my setup it took roughly 2 hours of grinding to get all my transitions smoothed out with no large steps or protrusions.

seeing as you have boost taper & your using a MBC i would say that is your primary problem. if you still have problems after fixing your boost taper you may want to check the exhaust path for flow restrictions & take a grinder to any spots that do not match up well, also clean up the step in the o2 collector where the exhaust stream from the wastegate feeds back in

 

A 3076 on c16 and high boost will lose 200 ft lbs of tq or so from peak to redline, the turbo cannot support the amount of air an engine wants at 30 psi and 6k+rpm.

Scorke

 

we tuned a 30R stock block ix not too long ago...25psi 93 made 386/300

a similar50 trim car made 403/330 at 22.5 psi..

cb

 

NVM looked at teh graph looks about dead on for pump gas, for race gas that is miles off.

Scorke

 

on a 2.0 or 2.3?

On a 2 liter, if the OP were to hold 28 psi to a 7500 RPM redline (assuming 90%VE), then the turbo would have to flow ~49lb/min, which a 3076 should have no problems accomodating. At 100% VE it would be ~54lb/min.

l8r)

 

Just because something is "based" on the best intercooler out (for example, some Ebay units look like the AMS intercooler, which has been copied) doesn't mean the actual core is even remotely in the same universe quality-wise.

There have been numerous examples of Ebay cores getting heat-soaked after back-to-back runs.

 

Before you had your VSR on your car and headwork done what was peak tq, at what RPM and at redline.

I know on my 30R on a 2.3 i dropped over 220ft lbs of tq I belive on c16, on the 2.0 and c16 it was over 150 ft lbs, wit a 440 ft lbs peak and finishing below 300 ft lbs at 8k.

Scorke

 

You should be very disappointed.

1. Get some Cosworth 272 Cams. Big turbo with no cams?!?!?
2. Kick your tuner to the curb.
3. Go to RRE and get dyno and re-tuned

You should be around 430 AWHP and 380 AWTQ (+/-) with C-16 and 28 psi.

 

I remember you posting that you were going to Harmon on SCE and everyone said it was a bad idea...looks like they were right. As stated above try someone else such as Tuning Technologies, Dr. G at RRE, or one of the other favs in socal. My suspicion other than the issues already raised is that it is the tuner. Also, before you do it, add the cams like I suggested before :-)

 

You should have looked at his "Pd1" posts before trusting him to tune your car. Tripping over dollars to save pennies on tunes is mine blowing. It is the most important part of the modding equation.

Get some cams.

 

So before we attack the tuner right away...lets examine some of the other aspects of this car shall we?

We have a stock diverter valve..check

Assuming its even an MR it doesnt mean its going to hold against the extra cfm that a 3076 produces versus a stock turbo at the same psi

HAFE + 3076= SBR...right?

What 3076 (compressor cover), which turbine housing, which A/R, how much turbine backpressure is being produced and the subsequent increase in EGT's and therefore knock potential even on C16.

Stock Cams...check

Sorry no matter what the stock cams arent good enough at high rpm scavenging to make good power with a big turbo. I have personally seen this more than once, including a recent dyno day. Stock cams and a White Rabbit vs. BC280's on a stock turbo. One had to be on 104 and 27psi to match the other running pump and 24. Even then the other car was 13whp higher. Those 2 cars were 8's, but the idea remains the same.

Ebay Intercooler...hmmm well...what does the internal fin design look like compared to stock. Several of the ones I have seen are smaller and therefore turn into a stop sign at high rpm.

C16...check

Did it come from a sealed pail or was it pumped out of a drum?

I am interested in the specs on the turbo more than anything.

Is is it a little rich for C16, yeah to me it is. I run 11.7 on pump and would be in the 12-12.2 range for race gas but thats me.

So before the hating begins, lets examine some of the other details to see what the cause of the malfunction is.

JB