HENNESSEY TURBO PERFORMANCE

[Supra]

Nice, those older Supras (MKIII's) are nice cars! Too bad they are very heavy ~3700 pounds.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by ronviper:
Supra i had a supra for 10 years 1987 turbo, silver in colour, Cartech intercooler, 3" stainless steel exhaust no cat, HKS wastegate, larger turbo, 55lbs injectors, VEC from HKS. fuel management system. The car would pull like a mother, wheel hop like crazy, bad et's but great mile per hour. The weak point was the clutch always slipping under high boost, even tried center force with no luck. Those cars rock with the right bolt on because the bottom end is very strong. Problem i had was always playing catch up but usually passed most cars in the top of third.

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[Supra]

This is only true at the manifold and in the combustion chamber. A turbo motor at 10PSI will make more power where it matters (to the ground) than if the same motor was running an SC at 10 PSI. This is because the SC itself takes a lot of HP to run. If the SC in question is the "typical" centrifugal SC it will only make peak boost at redline, further increasing the discrepancy in HP.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Shakedown:
Not so.


And by the way, all other things aside, 10psi is 10psi no matter what produces it.

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[davem]

Guys,
I get this a lot from import guys when tuning their cars on the dyno, and I always try to get them thinking in mass of airflow, not pounds of boost.

10 pounds is NOT 10 pounds depending on what produced it relative to making power. You care about "mass of air flow ", not pounds of boost. A small turbo at 10 pounds boost will flow less mass of air than a larger turbo at 10 pounds because the smaller turbo will heat it more, so you get less pounds or mass of air=less power. Depending on how far off the sizing is and how hard the smaller turbo has to work to make 10 pounds, this can make a LOT less power.

Same with a roots type blower -10 pounds from this will be less air than 10 pounds from a more efficient centrifugal blower - assuming both are sized correctly.

Same with comparing a blower to turbo, 10 pounds from each will make vastly different amounts of airflow and power.

On a related note, does anyone know exactly what the driveability issues are on the Hennessy viper in the Car and Driver shootout?

thanks,
Dave.

 

[Tom and Vipers]

I have no idea why I said Cummins and not Detroit Diesel... I think it is almost humorous that truck drivers did not always know that you don't lug a Gimmy.

Another argument in favor of turbos is that the import guys use them.

The import guys seem to solve the most challenging technical issues and I am certain if superchargers would produce more HP, the import guys would move over to them overnight.

The performance of Buick GN's is staggering.

The centrifugals, however, do give you evil, wicked top end. This is somewhat handy as a kitty when you are racing someone. If you need a little more HP, simply wind the engine a bit more.

Again, at max BMEP, the centrifugals are loafing and not flirting with detonation.

When an engine is running out of breath, it is the same thing as running at high altitude. To get power back, you supercharge.... or you can raise the compression ratio.

Same thing with restrictor plates. What were those NASCAR guns running, 17:1, 18:1?

 

[HP]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by King GTS:
Hugh do you have any pics of your RT that you could post. I just read your sig. very impressive.

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Trey, it's my intent to eventually post pictures. My computer
crashed a few months ago, and at the time I was trying to
do some video capturing, so I've been procrastinating(computer-burnout). But eventually I'll get to it.

 

[ronviper]

oneslowhemi, as you know it cost alot of money to play. I paid cash for the viper brand new and have a few bolt on's however i am having problems "mentally" whether to play too much with this car. It's ******* the pocket book to play with two car's at the same time, however next year the viper is three years old so maybe i will sell the buick and invest in the viper's performance. Nice talking with you.

 

[ronviper]

Oneslowhemi, my twin stage2 ran 8.70's however i sold that car now my present 4.1 has gn1 heads, 224 solid roller cam , forged crank, ross pistons, bowling green intake, 70mm throttle body, atr headers, lose 3500 converter, 83 lbs injectors, front mount intercooler from precision and pte 88 turbo. This is for street only but with dfi tuned properly should run 9.50 to 9.70's

 

[Tom and Vipers]

At the Reno Air Races a modified sport plane had a self-contained compressor strapped into a rear seat.

It was something like a 80 HP snow-mobile engine driving a centrifugal s/c. It was all plumbed for cooling air, fuel, etc.

Now that is boost w/o loss!

Maybe we need a new catagory APU boost!

Tom

PS. Now if there was only a way to harness the NOS nozzle blowdown energy....

 

[King GTS]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by KwikSnake:
Trey....you say J.H. will definitely be at the upcoming event in an 800TT. How come he was at the Vette/Viper Shootout last October(i believe it was Oct.) in a suburban? He was just walking around with his kids.

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Ummmmmmmmm. I don't know????

I think he had a Venom 800 TT & a 1000 TT at the drags. Did you see him there?