Turbo plenum

[Sumner]

....I see info about running a bigger compressor but not bigger intercooler................

Kent said:

i put 2 1000hp intercoolers on my liner

.....Sum, come on!!!!

Suzuki Vs. Kawa?

No contest!
(joke Kent)......................-JH

I thought I would let you say that since I'm having lunch with him this next week  ,

Sum

[Andy Cooke]

my 2p (that's UK pence)

Since you're running an icebox chargecooler the temperature and pressure at Bonneville is largely irrelevant (with respect to cooling).

However, the definition of an intercooler as 500hp, 1000hp, or whatever is spurious.  The cooling requirement of an engine that makes 1000hp at 1psi is totally different to one that makes 1000hp at 45psi.  I can only assume the rating is linked to a pressure drop at a certain flow, I don't know of any standard, so can't see how you can compare one manufacturer with another.

I think you need to tailor you questions to the supplier:

how many CFM will this thing flow with a 1psi pressure drop?  (that should confirm the flow rating)

The air coming out of your turbo will be something like 200C, so you next question should be; given whatever CFM you expect to flow, and 5C water, 200C air, what will the temperature of the air leaving the intercooler be?

The downsides of too much intercooler will be down to size, weight, and to an extent lag (although I'd have thought that was less of an issue in LSR).

Andy

[saltfever]

That would be my guess: heat rejection ~ D1^4 ÷ D2^4 in absolute temp, so the difference between 100° F ambient (actual) and 70° F (design) is (460+100)^4 ÷ (460+70)^4, or 983 ÷ 789, or 1.246.

Just couldn't figure how you got 983 out of (560)^4. But since I greatly appreciate the formula and the technical insight, I struggled with it until I finalized realized you rounded off to the bazillionth place. Had to put my calculator under a sun lamp to get it charged up!!

Assuming equal efficiency, you need +25% capacity for the higher temperature.
The reduced air density at Bonneville also reduces efficiency, I would guess in direct propotion to the altitude, so roughly 29.92 (sea level) ÷ 25.64 (4,214 elevation) = 1.167. If true, the combined factors total about +45%.

I have seen days at Bonneville when the density altitude can be 10,000 ft. So the benefit of an ice water intercooler is tremendous. Too big is not necessarily a bad thing . . . however, the fuel can be too cool! You start to have problems with poor fuel atomization, fuel puddling, uneven burn, etc.

Jonny, if you want to oversize the intercooler (because of future engine applications) you should probably thermocouple both the intake and the outlet so you know what temps you are dealing with. You can controll the outlet temp in various ways. By oversizing the intercooler you will be saving dollars in the long run. So putting a few $$ into temp sensors will be money well spent. Overcooling is a big looser and recording and knowing your temps will prevent that from hapening.

[panic]

An afterthought: humidity has to affect IC efficiency?
Is D/A a better predictor than simply ATM?

[panic]

Re: "but do you actually use a slide rule for your day job"

Nope, civil servant c'etait moi. My last "day job" before retirement was rapping attorneys' knuckles at the Matrimonial Part of Supreme Court of New York County (your tax dollars at work). The building should look familiar, it's the set of many, many movies and TV shows.

[Andy Cooke]

Too big is not necessarily a bad thing . . . however, the fuel can be too cool! You start to have problems with poor fuel atomization, fuel puddling, uneven burn, etc.

Do you have any experience of that happening with EFI?  I'm wondering how cool the charge needs to be for this to cause a problem.  I've had problems with carburettors and low temperature, but not noticed it with EFI.  I'm not talking about sub zero (Celcius) though.  I'd be surprised if you could get charge temperature as low as 10C, and I've competed with charge temps that low (helped by near zero ambients and relatively low boost).

Given 0C water (let's be optimistic) and 200C air, you'll need a 95% efficient intercooler (do they exist?) to get to 10C.  Who wants to share what IAT they get with an icebox at ~2bar?

Mind, all this drivel is talking about on boost, idling and what have you the IAT will be very close to the water temp.  None of my experience is LSR, so I'm listening and learning

[saltfever]

An afterthought: humidity has to affect IC efficiency?
Is D/A a better predictor than simply ATM?

D/A takes into consideration pressure and temperature. ATM is only pressure. 29.92" at 60F has far more air mass than 29.92 at 100F. Jetting and tuning is based on D/A. Humidity is not considered in D/A for racing. Don't know its affect on calculating IC efficiency. But dew point is another matter . . see next post.

[saltfever]

Do you have any experience of that happening with EFI?  I'm wondering how cool the charge needs to be for this to cause a problem.  I've had problems with carburettors and low temperature, but not noticed it with EFI. (snip . . .)
Given 0C water (let's be optimistic) and 200C air, you'll need a 95% efficient intercooler (do they exist?) to get to 10C.  Who wants to share what IAT they get with an icebox at ~2bar?

A couple of points to consider. The phase change from a liquid to a gas, of both gasoline and methanol, is endothermic (absorbs heat). If charge air is too cool, it is quite easy to have 30F deg below zero, down stream of the injector or in the carb venturi (if blow through). Ask a local pilot about the dangers of carb icing.  Because of poor fuel vaporization you can get strange flame propagation, weird EGTs, etc. The second issue is dew point. If the temp in the IC is below the dew point for the day you will get condensation inside the IC and your intake passages! Don't minimize this. Consider the mass of air your compressor is putting through your engine compared to a unblown. Now multiply that by the relative humidity and it is not a trivial matter. You can get water everywhere and/or icing. So to answer your question. IC outlet temp of 65F-120F Deg seems to work just fine. YMMV 

[Jonny Hotnuts]

This might sound crazy but why couldn’t you have a relay on the pump and an AIT to control the water flow in the intercooler.

Seems to me you could set a desired intake temp and the pump would move the water needed to keep that temp.

This way you could adjust the intake temperature to whatever you wanted.

[1212FBGS]

yep just another over thought trinket to possably go bad...keep it simple Jonny......really simple..... and you'll never have the buffet close before you get there...
kr

[Stainless1]

JNuts, don't worry, your intake charge will never be too cold in a turbo motor.  Intercooler efficiency can not ever be that good.  Depending on your boost level, your 200 to 350 degree air temp will never get cold enough to cause intake icing at Bonneville...    You just have to hope you can get it down to 100 degrees by the time it gets to the throttle plates.  Keep it simple, any thermal control will be running wide open anyway.

[Jonny Hotnuts]

yep just another over thought trinket to possably go bad...keep it simple Jonny......really simple..... and you'll never have the buffet close before you get there...
kr

I didnt mean to imply that this is something I was considering...only that it could work.

I agree about keeping it simple and currently the car is not. This is something I need to work on.

JNuts, don't worry, your intake charge will never be too cold in a turbo motor.  Intercooler efficiency can not ever be that good.  Depending on your boost level, your 200 to 350 degree air temp will never get cold enough to cause intake icing at Bonneville...    You just have to hope you can get it down to 100 degrees by the time it gets to the throttle plates.  Keep it simple, any thermal control will be running wide open anyway.

-JH


This is good because I got offered a sweet deal on a PT 2400. I would not normally choose one this size but the deal is too good to pass up.
http://www.horsepowerfreaks.com/partdetails/Precision_Turbo/Intercoolers/Intercoolers/Liquid_To_Air/7099

-JH

[Andy Cooke]

This is good because I got offered a sweet deal on a PT 2400. I would not normally choose one this size but the deal is too good to pass up.
http://www.horsepowerfreaks.com/partdetails/Precision_Turbo/Intercoolers/Intercoolers/Liquid_To_Air/7099

-JH

best get 2 just in case   How big is that beast?

mount it water pipes up unless it has a bleed.  Pump water into the air out end of the I/C.

With respect to keeping it simple I'd bin all the ECUs and fit one that does everything, one that you can plug a laptop in to remap, and see what all the inputs and outputs are doing, ideally with a logger built in.

[Jonny Hotnuts]

With respect to keeping it simple I'd bin all the ECUs and fit one that does everything, one that you can plug a laptop in to remap, and see what all the inputs and outputs are doing, ideally with a logger built in.

Andy as you know all too well something as small as a ground wire to the ecu caused 2 aborted runs and nearly a full day down.

I still dont completely understand why the engine would run perfectly in neutral and then go dead once it was put in gear but it was clearly the burnt spade on the primary ecu ground that caused the prob.

Unfortunately I dont know of a replacement for the stock ECU and the only way to really adjust them is through a piggy back injector controller.....and even thought there was a time that I was blaming the Bazzaz system it turned out to be something else. 
Even worse is that I am going to have an additional box (megasqurit) to control the secondary injectors.


I am open for suggestions.

---------------------------------------------------------------------------------------------

All joking aside there is considerably more technology on that car then when to the moon.

Sad.

[maj]

ecu editor as discussed on SHOrg has a lot of potential for eliminating extra engine managers.