Questions about Callaway Twin Turbo Drivability????

[Hog]

I've heard that story a lot regarding TPI. LB9 and L98 350 were introduced for the 1985 IROC-Z and 85 Corvette respectively. The L98 was about 3/4 of a second quicker in the 1/4 mile over the 1984 Cross Fire Injection.
Another is the way the TPI works, its reasonance frequency literally "supercharges" the intake air into the cylinder. This is why the TPI makes incredible mid rpm torque. Gen 2 LT1 SBC couldnt touch L98's 350lb/ft of peak torque, but excelled in other areas. But operate the TPI ouside of the resonance rpms and this effect is muted and other restrictive forces take over.
Literally forcing the air through like what happens in these B2K cars, would help out this upper rpm starve off.

The SLP diamesed runners help, as do the larger Arzona Speed and Marine.
The TPI runners that were to be used on the 1992 (Heritage??) Camaros that were to be outfitted with the ZF 6 speed would also be a great find.

7.5:1 c/r doesnt help to make an engine feel responsive, the 2.9 liter Ferarri F40 also used a low 7.7:1 c/r to make 470+ hp with DOHC and 16 psi of boost.
I'd love to see a B2K with some modern combustion chambers that would allow some increase in static compression. I did a Vortec 355/TPI and it worked well without any exotica. I can only dream of how that would behave with a couple turbos breathing on it.

Were all B2k Corvettes speed density, or did they follow GM's 85-89 MAF then 90-92 Speed density routine?
Those early GM MAFs were horrible flowwise.

[alnukem]

Lee.........what else do you have in that garage?????? Come on, fess up, is that where all the surplus JATO rockets are????

I have never driven a stock L98. My friend has one with a Paxton on it.

It is very mild mannered till you hit the gas? With the big torque number, I would think it would set you back in the seat? Is that the feeling?

[Kevin]

had a stock l98 before the zr-1 and yes it will put you back in the seat, but so does the zr-1. I think I remember it chirping third, if you come out to cars and coffee next year I can introduce you to a guy with a stock l98. It's a fun car to drive but doesn't do anything the z can't

[Hog]

Originally Posted by Kevin

had a stock l98 before the zr-1 and yes it will put you back in the seat, but so does the zr-1. I think I remember it chirping third, if you come out to cars and coffee next year I can introduce you to a guy with a stock l98. It's a fun car to drive but doesn't do anything the z can't

I'd love to see a stock L98 and LT5 Y-body with the LT5 have its Port Throttles closed, go at it in a supervised acceleration trial.

Dyno Port Throttles Open vs. Closed at WOT (thanks Mr Beham)

[Kevin]

either i'm really drunk of that's a picture of bigfoot

[Hog]

Originally Posted by Kevin

either i'm really drunk of that's a picture of bigfoot

Yes it's a picture of bigfoot.

[Schrade]

Originally Posted by Hog

I've heard that story a lot regarding TPI. LB9 and L98 350 were introduced for the 1985 IROC-Z and 85 Corvette respectively. The L98 was about 3/4 of a second quicker in the 1/4 mile over the 1984 Cross Fire Injection.
Another is the way the TPI works, its reasonance frequency literally "supercharges" the intake air into the cylinder. This is why the TPI makes incredible mid rpm torque. Gen 2 LT1 SBC couldnt touch L98's 350lb/ft of peak torque, but excelled in other areas. But operate the TPI ouside of the resonance rpms and this effect is muted and other restrictive forces take over.
Literally forcing the air through like what happens in these B2K cars, would help out this upper rpm starve off.

The SLP diamesed runners help, as do the larger Arzona Speed and Marine.
The TPI runners that were to be used on the 1992 (Heritage??) Camaros that were to be outfitted with the ZF 6 speed would also be a great find.

7.5:1 c/r doesnt help to make an engine feel responsive, the 2.9 liter Ferarri F40 also used a low 7.7:1 c/r to make 470+ hp with DOHC and 16 psi of boost.
I'd love to see a B2K with some modern combustion chambers that would allow some increase in static compression. I did a Vortec 355/TPI and it worked well without any exotica. I can only dream of how that would behave with a couple turbos breathing on it.

Were all B2k Corvettes speed density, or did they follow GM's 85-89 MAF then 90-92 Speed density routine?
Those early GM MAFs were horrible flowwise.

Calloway MUST re-worked the intake on his B2K's???

(unless GM said no, since they umbrella'ed his work under their own warranty - only one I've ever heard of whose work GM covered)

[LGAFF]

Callaway only opened up the TB on the plenum....everything on the intake was stock, cams stock, exhaust was close to stock. Keep in mind they had to please the EPA as they were considered a manufacturer. I believe they had to recall some B2Ks because they put Audi cats on them.

The heads had new valves and springs in them...no porting

[Vetman]

I put 50,000 mi on a L-98 six speed 1990. Very torkie. Drove much like my z to about 3000
Rpm but my z would leave it big time from then on!!!!