Which intercooler to go for?

[Gareth Davies]

Quote: from Paul Whiffin on 10:49 pm on Jan. 19, 2002[br]... Single seems to be better, apparently an Sound Performance SP57 kit will spool quicker than the stock twins in sequential mode and still able to produce huge amounts of power.

Surely you mean stock twins in true twin mode not sequential... the difference is between power delivery at 1500 rpm or 3000+ rpm.

 

Assuming similar design big twins will always deliver power faster than a similar power single. The SP57 kit in the global scale of things is actually a 'small' single (however we are definatly talking relative terms here). Comparing a turbo good for ~600 rwbhp to one capable of ~800+ is a bit unfair.

[Syed Shah]

I am not saying that they are all bad, but you have to admit 450rwhp from a BCC, Zorst and downpipe is a tad unrealistic.

[Alex]

G, I think Paul meant Full boost which would be about 3,800rpm

 

Big twins as Paul says are too laggy compared to a big single (though I would pick the T51R/T04R or PHR2 as the direct competitors) when using the car in a street application.

 

But mid twins like the 2510 could be done. The 2510's tend to get boost from 3500rpm but will generally max out at about 600hp, 300hp each.

 

The rev limiter on a Supra is much lower than, for instance, a Skyline. Because of this "street applications can't really make use of big turbo's unless the rest of the system is really well prepped first.

 

A turbo is only as good as the engine its bolted to. If the eingine can flow enough air then go for big twins - enjoy spending the money on gas flowing, porting, adding a stroker kit and boosting the fuel system if you really want big twins to work well.

 

As for the 450hp off of those mods...yeah its stretching the truth and even the fact that they run race gas con't really explain it.

[Syed Shah]

On the subject of the rev-limit, PHR claim to do up the engine to be able to go to 9000rpm.

 

Is this safe, or are they just abusing the engine, because if it can be done without stressing the engine, I think a 9000rpm redline could be a lot of fun :biggrin:

[GavinL]

Quote: from Syed Shah on 3:06 pm on Jan. 20, 2002[br]I am not saying that they are all bad, but you have to admit 450rwhp from a BCC, Zorst and downpipe is a tad unrealistic.

 

I believe that US dyno's measure horsepower in another way too an UK or Jap dyno. If you knock about 20% of an American HP figure it brings it back roughly into line with us.

[Alex]

Quote: from Syed Shah on 8:34 pm on Jan. 20, 2002[br]On the subject of the rev-limit, PHR claim to do up the engine to be able to go to 9000rpm.

 

Is this safe, or are they just abusing the engine, because if it can be done without stressing the engine, I think a 9000rpm redline could be a lot of fun :biggrin:

 

Its possible and pnd probably the first thing I'd do if I had the cash. :biggrin:

[Alex]

http://vache.org/supra/turbos.htm

 

Is a good comparison chart page - scroll down for the dyno's and cars they were performed on.

[Guest Martin F]

 

If you do don't forget to mod the oil pump.

 

A lot of people have found that as soon as you go over the stock limiter that the oil pressure relief valve can not cope.

 

 

[Chris Wilson]

Quote: from Alex Holdroyd on 8:12 pm on Jan. 19, 2002[br]The bigger the intercooler the more lag you will suffer unless you do other mods at the same time.

 

Why induce more lag than strictly necessary if your only going to need the efficiency of a R type.

 

Lag is unlikely to be even measurably increased whichever of the conventional aftermarket I/c's you fit. the Apexi core is bloody odd, and masks the hell out of the water rad, i see problems on many different cars on the track with the Apexi unit starving a water rad behind it of air, although their blurb seems to suggest the opposite should be true. The top of the range HKS one uses a good core, and its the core and the air flow to and from it that is the most important. A stock MKIV front bumper renders a large percentage of most aftermarket I/c's purely along for the ride anyway. I have the same problem with my RX-7. i can use a conventionally BIG I/C behind and aftermarket bumper and probably gain a LOAD of aerodynamic drag, or buy a really expensive core and use a smaller but more efficient I/C and water rad. i will probably take the latter route, but in none of my thinking am i worrying about lag, unless pipe runs are huge and very convoluted and the I/C is 14 litre diesel truck sized it can be forgotten about. Core design and air flow from a high pressure area to , only through and not around, and back out of the I/C to a low pressure area are all you need worry about.

[Chris Wilson]

Quote: from Alex Holdroyd on 8:12 pm on Jan. 19, 2002[br]The bigger the intercooler the more lag you will suffer unless you do other mods at the same time.

 

Why induce more lag than strictly necessary if your only going to need the efficiency of a R type.

 

Lag is unlikely to be even measurably increased whichever of the conventional aftermarket I/c's you fit. the Apexi core is bloody odd, and masks the hell out of the water rad, i see problems on many different cars on the track with the Apexi unit starving a water rad behind it of air, although their blurb seems to suggest the opposite should be true. The top of the range HKS one uses a good core, and its the core and the air flow to and from it that is the most important. A stock MKIV front bumper renders a large percentage of most aftermarket I/c's purely along for the ride anyway. I have the same problem with my RX-7. i can use a conventionally BIG I/C behind and aftermarket bumper and probably gain a LOAD of aerodynamic drag, or buy a really expensive core and use a smaller but more efficient I/C and water rad. i will probably take the latter route, but in none of my thinking am i worrying about lag, unless pipe runs are huge and very convoluted and the I/C is 14 litre diesel truck sized it can be forgotten about. Core design and air flow from a high pressure area to , only through and not around, and back out of the I/C to a low pressure area are all you need worry about.

[Chris Wilson]

Quote: from GavinL on 8:36 pm on Jan. 20, 2002[br]

Quote: from Syed Shah on 3:06 pm on Jan. 20, 2002[br]I am not saying that they are all bad, but you have to admit 450rwhp from a BCC, Zorst and downpipe is a tad unrealistic.

 

I believe that US dyno's measure horsepower in another way too an UK or Jap dyno. If you knock about 20% of an American HP figure it brings it back roughly into line with us.

 

 

OOOOHH! This DOES wind me up!!! BHP is BHP, pounds foot of torque or kgms/ meter of torque is the same EVERYWHERE in the world. the Yanks say this because they got so giddy each outquoting the next guy with BS power figures that when a European measures them accurately there is a big difference. It's called BS, that's waht any different "ways of measuring HP" is. Total BS!

 

Yamaha did the same, they developed 5 valve per cylinder heads for the Cosworth DF* series engines for F1. "We have found another 18 BHP and another 20 ft lbs of torque", they claimed. Cosworth waited for the engines to be shipped back, checked on their own dynos under identical conditions and replied that the European horse seemed to be a much superior animal :-) The US do NOT measure BHP differently, it's just their inertia type rolling roads must be calibrated to flatter their engineering.

[Syed Shah]

Leon was getting a bit annoyed about this, being told by PHR that to achieve their power figures, he must use race fuel. But of course even with that, you can't catch upto their figures

[Guest Martin F]

 

Thanks for the replies Chris.

 

If you stop and think about it a minute it makes sense that 1BHP is 1BHP wherever in the world you may hapen to be.