Charly

Tan, now I won't feel so self conscious about some of my posts
Thanks, Charly

Charly

mechy, I think netwiz meant FI as in fuel injected, but I'm not sure. Charly

RodneyK

In this context FI = Forced Induction

mechy

Ok thanks guys, I thought it said F1, and since it make perfect sense to me then I was even more sure...

Turbos are nothing without intercooler, youre just feeding some hot air to engine, increasing compression ratio thus retarding timing!

If your gonna put a turbo, put an intercooler, believe me!


Cheers

RT

There are plenty of applications where no intercooler is present, and the turbo is SOMETHING, believe me!

Pinky

[QUOTE]
Originally posted by mechy

Tanqueray

Pinky,

There is very little temperature gain from the exhaust gases heating the charge air. According to Corky Bell's book, the increase is temperature is due to the compression of the charge.

In addition, the typical charge temperature increase for a 12psi turbo is 200 degrees. The change in density (and therefore the change in power) is calculated using the absolute temperature scale. Here are a series of approximate calculations showing power loss/gain for a turbo with/without intercooler on an 80 degree day.

Power loss due to charge temperature increase, no intercooler:
540
----------- = .73 ==> 27% loss
540+200

Assuming an 70% efficient intercooler:
540
--------------------- = 10% power loss
540 + (.3 * 200)

However, if you ignore heating effects, a 12psi turbo will provide:
14.7 + 12
------------- = 82% increase in power (to the 1st order of accuracy)
14.7

Assuming a 100hp stock engine ,
adding turbo gives (100 * 1.82 * .73) = 133hp
adding turbo with IC gives (100 * 1.82 * .90) = 164hp

A 6psi turbo adds about 1/4 as much heat to the charge, meaning a much smaller power loss without intercooler.
Assuming a 100hp stock engine ,
adding turbo gives (100 * 1.41 * .92) = 130hp
adding turbo with IC gives (100 * 1.41 * .97) = 137hp

So, an intercooler will provide more power, but you will get a big kick with or without it.
Tanq

Pinky

uhhhhhh............yea what he said! Well it gets F-ING HOT that is for sure!

Though you won't see my car with either a SC or Turbo. If things go well enough that I can afford it I am going to be Porting my S.(when it turns into a weekend/track car). It should be a torque monster by then! Im not telling by whom its a secret(if his past performance is any indication of what he can do)

derryck

First of all, the S2000 engine is an F20C not a K20C. I believe the K20C is the RSX motor, not sure on that one though. It's not a good idea to turbocharge the S2000 without an intercooler. Your biggest enemy here is detonation which will be helped out quite a bit by having a large intercooler. If you're considering a turbo, you're better off to go with a kit like mine (the Speedcraft) or wait for Mark's kit. We have already worked out the bugs. This isn't the easiest car to work with when it comes to FI and I would highly recommend against cutting corners and costs. As for the 10-15% increase figures, I don't know where they came from but they are not even close.

mechy

They came from some semiaccurate calculations, and if their not even close then what are your figures?? They must be smaller, because an unintercooled turbo is NOTHING.