If you are seeing a 10 PSI pressure drop across the intercooler...you had better find the rag you left in there

 

You have a time slip from a 1/4 mile track?

 

No , but that video should be enough . Cars that do 13s 1/4mile trap around 110 mph don't they ?

And I don't think Greg is seeing a 10psi drop , perhaps he needs to clarify that here.

From another thread , here is the test I did a while back ...

 

I am working on sponsoring Gregs an intercooler. It won't be the typical intercooler set up.

Man that greddy intercooler is a restriction. I don't even know why you are arguing the fact. The Greddy cooler would be fine if the volume could pass through it. He is running methenol injection.

 

Because i actually did a test and measured the results . I guess the larger IC i used could be a bad design

I don't really have a horse in this race but would like to help because I have gone through all this myself and would like to see some better results from others . Particularly greg because he has put a lot of effort into his setup ...

 

Wow that fired me up to go FI this summer.... that is hella fast compared to stock!

 

Hopefully someone posts up some numbers with the new actuator soon..

 

You can tell the car makes good power, but it isn't against a clock. The great thing about a track is the time starts when you move from the tree and the clock stops when you go accross the finish line. If the car runs, go run it just like you did in the clip. And you can be in the 12 second club if you hook :D.

 

NO ONE IS SEEING A 10 PSI DROP ACROSS THEIR INTERCOOLER!

Why does this keep getting repeated.

Someone is confusing Gregs mention of high and low boost numbers across the RPM band with his 1 PSI measured drop across his intercooler.

I'll try to go through this thread and address all the other mistakes, but that one keeps coming back and it's annoying.

 

It was supposed to be funny Hence the smiley face..

 

This is serious business Dan - no joking allowed .















JK

 

where did you get the 1 PSI number from ?

 

Question for Bryan :

When you look at different T04e compressor wheels available there seems to be inconsistencies in the flow charts .
IE
maximum flow
50 trim - 48lb/min
54 trim - 45lb/min
57 trim - 44lb/min
60 trim - 50lb/min

I was led to believe that the larger the inducer diameter the more flow (with same exducer) but these numbers seem to make a mockery of that .
How can a 50trim flow more than a 57 trim ?

 

The 54-57-60 trims are of the same casting. The 50 trim is a totally different casting. The 54-60 trims have a cliped front side and the design isn't really aggressive for high volume. The 60 trim on a 13B is only good for 350 WHP. It is super responsive. You see a good amount of boost, but the car is lazy because the compressor doesn't make any TQ. I was very disapointed in the 60 trim when I tried it out.

The 50 trim is more aggressive in design. The compressor wheel is actually taller than the 54-60 trims. More blade area usually fits more volume. So things like tip height and the overall height play a major roll in how each compressor flows.

I had a 64mm inducer compressor on my FD one time from some Schwitzer turbo. I thought it would work out nice compared to the 62-1, but the most I could get out of it was 409 RWHP. That was at 20 PSI lol. The 60mm 60-1 would out perform that at 16 psi. Some compressor wheels just don't do well in certain applications. Its more of a trial and error kind of thing to find the right combination.

The 54/57/60 trims are very popular for people with SOHC 4 bangers that have restrictive heads and cams. Even the entry level turbo for the Grand National is a TA49 which is a 60 trim compressor. People dip into the 11's with a stock heads and cam GN, but that is pushing it to the limits. My 87 GN went a 7.28 in the 1/8, but it fell dead after that lol.

Also the 50 trim isn't 50mm inducer. I will have to check, but if I can remember the inducer is 54mm.

Bryan

 

Thanks for the in depth explanation - makes sense now .

 

"Trim" is not wheel size (directly).
It is the "ratio" of the inducer to exducer sizes.

 

and there's the explanation in 2 short sentences.

 

for reference - iducer exducer size in last two columns

 

Or, you could just look at the specs and do the math.

 

You will not know what a compressor will do in all aspects until you experience it behind the wheel. Math gives you an idea what will work and what won't but still you don't know exactly how compatable it is as a total package.

I like telling people a certain turbocharger gets 20 psi by 4500 RPM, makes peak TQ at 6800 RPM, 485 RWHP peak, and averages 430 RWHP throughout the power band. A compressor map doesn't give you those facts.

 

It absolutely does. (If and when they are "facts". Those are actually quite vague promises to make.)

 

Jeff. there is more than one part of a turbocharger that can effect the compressor and how it works in the car. A compressor map cant tell you the whole story on a turbocharger. There are too many variables associated with the engine that can drastically change spool up. Compressor maps don't have any calculations for turbine housing size, turbine wheel changes, or if you change your manifold runner lengths ect. You must know exactly what the Volumetric Efficiency of the engine in order to get close but it all depends on the whole package. That VE changes when you change port timing, change turbine housings, change up intake manifolds, exhaust manifolds ect. Too many variables that can cause flow improvements of the engine or flow restrictions....

 

Nothing affects the way the compressor works. It is an absolute.
How the car performs is affected by many things, but the turbo's compressor does exactly the same thing, every time.

Uh, yes they do. They are called turbine maps. They work just like the compressor maps.

I respect the trial-and-error method that you employ, but most of your time is wasted this way.
ALL of the differences you describe in different applications with different turbos can be completely quantified by using the provided documentation and applying the math.
Turbo manufacturers are not stupid. The data they provide is extremely well acquired.

 

I agree with you about the absolute in both the turbine and compressor maps. The variables start with longer/shorter diffuser lengths and larger/smaller a/r's around the compressor/turbine wheels. In application all the variables surrounding the turbine and compressor wheels will effect how it works in the car. Thats where I was trying to get at pretty much this whole time. Same way engine changes.

A lot of the stuff that we do with ported wankel engines isn't bench tested so we don't know the exact calculations for VE. Most of it is estimated or going off of a basic formula. How can you be exact with calculations when there are so many variables?



Garrett is beyond me. I just apply their products to factory production turbochargers.

Thanks for the respect. I wouldn't have a business right now if it weren't for trial and error. I don't consider any of it a waste of time.

What I base everything on is improvement on weak points in a factory turbocharger. When issues pop up like the boost fall off and flow restriction problem, you have to push through and fix the problems. I don't want to offer a product that doesn't work...

 

AFAIK the compressor/turbine maps are specific to each of these variables. ie different map for each potential setup.