Question for the turbo gurus

[Stroked87]

Took my car to the track for the first time since the turbo build last night, car seemed to run ok considering that it has no tune and still needs a good fuel system. During the testing I was changing the amount of boost with a manual dial-a-boost from completely all the way down to full boost in increments, however I saw absolutely no change in my E.T.s or MPH but the turbo did get noticeably louder every time. What would cause this?

As far as the specs of the motor, it has the following:

Engine:
302 Summit Block
Eagle 347 Stroker Kit
Dart Pro 1 CNC Heads
FMS X303 Cam
Cartech "Breadbox" Intake

Turbo System:
60 mm turbo
Tial 44mm Wastegate
Manual Adjust Boost Controller

Let me know if/what more info you may need....

[Daniel6718]

why would you even consider running your car untuned without a fuel system to keep up?

how is the wastegate plummed?

[Doug Hatton]

You saw no change in ET or MPH, but you did observe an increase in boost?

[black50]

no tune and no fuel system..

You are just asking for bad trouble...You were probably leaning way out which is why you saw no et decrease, and you are very lucky you didnt blow that motor

[shumpertdavid]

invest in a good wideband, not the crappy a/f gauge, so you can monitor your rich lean status. as stated above you're asking for trouble with no tune.

[Misfire]

no tune and no fuel system..

You are just asking for bad trouble...You were probably leaning way out which is why you saw no et decrease, and you are very lucky you didnt blow that motor

unless you were running rich at lower boost you are just burning it up.

[Stroked87]

You saw no change in ET or MPH, but you did observe an increase in boost?

Correct, although I am not sure that I even saw an increase in boost. Seemed that even after turning it to full boost I only saw about 9lbs.

[greenbullitt]

thats an awfully small turbo for that displacement

[turbostang]

you have a few problems, but I'll start on the easy stuff -

First, is the boost controller hooked up right? (bottom of gate should be to vacuum source - between throttle blade and engine, top to pressure source and boost controller)

Second, What spring is in the gate?

Third, the most glaringly obvious problem is the turbo. It's too small. My guess, it will make about 450-500HP and be done.

Now, it gets worse, if this is a "china" turbo, it's not even a 60MM and that 450-500HP drops to more like 375-450 on a good day.

The last reason will explain low boost and no gains in ET. Even if the tune is jacked, you should have noticed gains and blown it up at elevated boost levels.

What did it run?

[1bad91]

On a side note, Fransisco308 has a really nice precision unit that would make nice hp on your setup. You should hit him up.

[greenbullitt]

On a side note, Fransisco308 has a really nice precision unit that would make nice hp on your setup. You should hit him up.

i dont think his is big enough for that motor either

[Stroked87]

This is the kit that I have:

http://www.hpperformance.com/1979-95mustangturbosystems.htm

What I don't understand though is how I would see absolutely no difference from the boost being turned all the way down to all the way up regardless of wether or not the turbo is to small unless the boost controller is hooked up wrong or the waste gate isn't working correctly. It appears that neither of those is the case, although I do not know how to test if the waste gate is working. How can I check on this. BTW, thanks for the replies so far...

[Steve]

This is the kit that I have:

http://www.hpperformance.com/1979-95mustangturbosystems.htm

What I don't understand though is how I would see absolutely no difference from the boost being turned all the way down to all the way up regardless of wether or not the turbo is to small unless the boost controller is hooked up wrong or the waste gate isn't working correctly. It appears that neither of those is the case, although I do not know how to test if the waste gate is working. How can I check on this. BTW, thanks for the replies so far...

Matt, listen to Brooks (turbostang) the man knows his stuff and is good people. He won't steer ya wrong. Hope you get the issues worked out bro.

[turbostang]

This is the kit that I have:

http://www.hpperformance.com/1979-95mustangturbosystems.htm

What I don't understand though is how I would see absolutely no difference from the boost being turned all the way down to all the way up regardless of wether or not the turbo is to small unless the boost controller is hooked up wrong or the waste gate isn't working correctly. It appears that neither of those is the case, although I do not know how to test if the waste gate is working. How can I check on this. BTW, thanks for the replies so far...

Youre getting too hung up in "boost", like everyone else does.

Ignore "boost" and focus on POWER. I've said it a million times, boost is only a measurement of what air the engine can NOT ingest.

Now, having said that......First, you have to answer the questions I posted above - accurately.


Next, the explination of your problem - or what appears to be your problem....Your engine, just guessing.. makes, say, 400HP. (it's probalby more, but for comparison's sake..)

Now, at 14.7lbs of boost, it should theoritically double that power - so, 800HP. (14.7 is atmostpheric pressure, where your engine makes "400HP" - so doubling atmosphere it "should" make "double" the power)...so, back to the comparsion - it should make 800HP at 14.7lbs boost.. Here in lies the problem - that turbo can't support enough air flow to create 800HP. Not at the flywheel, the wheels, the moon - anywhere.

If you do some simple math, and just guess - and say at about 7 psi, it should pickup ~200HP, your turbo is SPENT - because now it's flowing enough air to produce ~600HP (remember 400HP engine, 200HP from the turbo). At that point, you are overspinning the turbo and creating a lot of heat in your newly compressed air... aka, doing nothing but tearing shit up. Now, albeit - those are not highly accurate numbers - because turbo flow changes at certain pressure ratios etc.. but I promise you one thing, my numbers are generous and in YOUR case- the examples are probably worse.