Intake Temp vs. HP

[BadAssPerformance]

Anybody got a reference between intake charge temp and HP? I'm thinking there has to be some correlation type 'rule of thumb' out there?

Maybe I'll look thru some data logs and see if I can relate it to ET & mph...

[Frank]

Using a race built 2.5L with 500 crank HP and 150degF intake temp, it would require 31.3 psi. However 200degF would need 34.9psi and 100degF would need 27.7psi. This just goes to show you that a crappy intercooler or an over taxied turbo can really make a difference.


Frank

PS. This is done with formulas, not real life experience.

[BadAssPerformance]

So at lets say at 25psi, what is the HP variation in the example 2.5L as intake temps vary from the example 150degF intake temp?

[Frank]

At 25psi and the 2.5L race example above,
100degF -> 467hp
150degF -> 429hp
200degF -> 396hp



Frank

[8valves]

I'm feeling better and better about this coming spring's dyno time with more info like this.

We use an SBR "monster" core on my brother's Talon. With a Innovative T67 wheel pushing 24-25 psi (wastegate spring) the car will hold 53* F intake temps with ambient being 44* F all the way to 6K rpms (runs out of fuel pump at this power level so we limit rpms there for now, just to clear that up). How's that for efficiency!? 3" plumbing from the turbo discharge to a 65MM TB. The front bumper is all hacked apart, although neatly, to get the whole surface area open to the wind.

Aaron Miller

[TurboMinivan]

the car will hold 53* F intake temps with ambient being 44* F all the way to 6K rpms. How's that for efficiency!?

It depends, Aaron. Does it hold this temperature just through first gear? Or can it maintain the 53^ temp during an entire quarter mile blast through first, second, third and fourth gears?

-Dempsey

[8valves]

It depends, Aaron. Does it hold this temperature just through first gear? Or can it maintain the 53^ temp during an entire quarter mile blast through first, second, third and fourth gears?

-Dempsey

This was actually a country road test... in fifth gear. We wanted to be sure! :D At the cars power output a 5th gear roll in from 2500 rpms all the way to redline of 6K in 5th didn't take too long, but it was the longest load we could put on it to see how it did. Even in the dyno cell w/ only three small fans, up to 6K rpms the cars intake temp highest logged would be 76 degrees, and this was on a 52* ambient temperature day outside, of course a bit warmer inside.

Aaron Miller

[TurboMinivan]

This was actually a country road test... in fifth gear. We wanted to be sure!

Nice! Glad to hear you guys were thinking things through. :thumb:

-Dempsey

[Ubmbass]

So, wait, fifth gear 6000 rpm in a dsm? What's that, like 170mph? no wonder your temps were so cool LOL.

[Mario]

I'm feeling better and better about this coming spring's dyno time with more info like this.

We use an SBR "monster" core on my brother's Talon. With a Innovative T67 wheel pushing 24-25 psi (wastegate spring) the car will hold 53* F intake temps with ambient being 44* F all the way to 6K rpms (runs out of fuel pump at this power level so we limit rpms there for now, just to clear that up). How's that for efficiency!? 3" plumbing from the turbo discharge to a 65MM TB. The front bumper is all hacked apart, although neatly, to get the whole surface area open to the wind.

Aaron Miller

Do you know what brand of core Slow Boy uses?

I think a new intercooler, a bit of cutting and fiberglassing in the front fascia, and some nice metal ducting to direct airflow will get that slow car of yours moving. :p

[8valves]

So, wait, fifth gear 6000 rpm in a dsm? What's that, like 170mph? no wonder your temps were so cool LOL.

Not sure honestly, the car has a full autometer guage cluster and we hadn't calibrated the speedo yet, nor was the vehicle speed registering through the ECU which was an entirely different problem. I have no idea, but I doubt it was that fast, probably more around 140 or 50 or so? It was tough to guestimate, the car smacked the limiter real hard which kinda caught us off guard.

SBR use garret/precision cores. It's 4" thick, I think 13 or 14" tall and the core size is over 30" off the top of my head. They don't even list it on SBR's site. Go look through precision cores and find the one rated at 1200 hp I think that is around those dimensions. They all could be off a bit though so let me know what you find.

Aaron Miller

[Mario]

Closest one I could find on Precision's site is:

24x12x4 Rated at 1150HP
24x12x4.5 Rated at 1300HP

The one they have that's 30" Long is only 2.76" Thick and rate at 1325HP.

They're highest rated intercooler core is 27.8"x12.75"x5" Rate at 1775HP :eek:

[8valves]

24x12x4 Rated at 1150HP


That's the one. I must be thinking end tank to end tank is over 30". Think of a 2G talon front bumper and the piping runs where the foglights used to be, pretty broad.

I'm still telling you, precisions 600/750 coolers are the best bang for the buck. Proven absolute top notch quality, flow, and cooling, no sacrifices. Plus on Ebay Precision sells them for 355 shipped or 450 shiped for the big --- 750. I know what I'm getting :p

Aaron Miller

[Mario]

That's the one. I must be thinking end tank to end tank is over 30". Think of a 2G talon front bumper and the piping runs where the foglights used to be, pretty broad.

I'm still telling you, precisions 600/750 coolers are the best bang for the buck. Proven absolute top notch quality, flow, and cooling, no sacrifices. Plus on Ebay Precision sells them for 355 shipped or 450 shiped for the big --- 750. I know what I'm getting :p

Aaron Miller

Which one are you looking for? The one rate at 750HP? If so, then I'll try and look for one.

[gasketmaster]

I'm still telling you, precisions 600/750 coolers are the best bang for the buck. Proven absolute top notch quality, flow, and cooling, no sacrifices. Plus on Ebay Precision sells them for 355 shipped or 450 shiped for the big --- 750. I know what I'm getting :p

Aaron Miller

Those are GREAT intercoolers :thumb:

[Mario]

Those are GREAT intercoolers :thumb:

:lol: You changed your reply.

[gasketmaster]

:lol: You changed your reply.

Yeah......I forgot which site I was on :D

I'm not an authorized dealer on this site yet so I thought I'd better mind my P's & Q's until I am ;)

[8valves]

Yeah......I forgot which site I was on :D

I'm not an authorized dealer on this site yet so I thought I'd better mind my P's & Q's until I am ;)

Aha! Sorry I didn't pick up a cooler from you during the Precision sale, I just couldn't do it at that time. But yes, they have proven themselves to me on multiple cars now.

Aaron Miller

[TurboJerry]

5 to 7 hp per 10 deg F.

[Dave]

Frank what's the formula??

Intake temp matters almost too much. To ambient air to the charge. I noticed a gain in power in moving my TII i/c from the stock location to sideways behind front bumper cover. Also noticed a good gain and spool up time from my stock intake (stock turbo inlet hose with a 3.5" APC filter elbowed off it between the battery and strut tower. ribbed piping) to my 3" mandrel bent intake sitting right behind the grill.

I'd like to see some dyno charts relating to readouts from the intake temp. sensor.

[Frank]

Frank what's the formula??

Intake temp matters almost too much. To ambient air to the charge. I noticed a gain in power in moving my TII i/c from the stock location to sideways behind front bumper cover. Also noticed a good gain and spool up time from my stock intake (stock turbo inlet hose with a 3.5" APC filter elbowed off it between the battery and strut tower. ribbed piping) to my 3" mandrel bent intake sitting right behind the grill.

I'd like to see some dyno charts relating to readouts from the intake temp. sensor.


Well using the formulas built into my turbo calculator, I get the following....

All for a race motor configuration...
100*F at peak hp of 450hp near 5500rpms, you would need 23.6psi.
150*F at peak hp of 450hp near 5500rpms, you would need 26.9psi.
200*F at peak hp of 450hp near 5500rpms, you would need 30.1psi.


Frank