Questions about Callaway Twin Turbo Drivability????

[alnukem]

I hope I didn't violate anything, since this is not ZR-1, but I wanted some input. I am starting to see Callaway Twin Turbos coming into my humble price range. I know there are members that must have had or have these cars. I have never owned or drove a turboed car before & was curious of the driving performance.

1988 RPOB2K Performance

382 BHP @ 4000 RPM
562 Torque @ 2800 RPM
0-60 in 5 seconds
0-100 in 12.4 seconds
1/4 mile in 12.8 to 13.7 depends who you read.

I guess there are some pretty simple & effective performance mods with a low restriction exhaust & a Callaway "Wonderbar" (apparently, a less restrictive frame channel for Air Inlet). Anyway, what's it like to drive one of these cars with, not so much HP & a ton of Torque????? Thanks, Tim

[LGAFF]

I bought 1987 #17 a few years ago for $13K. It was in rough shape; rebuilt the turbos, all of the lines were leaking, trans leaking. Its a pain in the *** to work on and they are sensitive to changes.

I do not think my experience is typical, but tuning with mods using the Callaway system requires some expertise. I have a prototype intake on mine, I also have the last copy of the sledgehammer cam made by Dave Generous(not installed) along with a wonderbar(not installed).

If you have means, I would say go for it. I would expect to spend a few K on repairs.

They drive like an L98, and power comes on differently than a LT-5....its like something pushes the car from behind

[LGAFF]

http://i134.photobucket.com/albums/q115/lgaff/DSCN5021_zpsd6708225.jpg (http://s134.photobucket.com/user/lgaff/media/DSCN5021_zpsd6708225.jpg.html)

[Z06scentair]

http://i134.photobucket.com/albums/q115/lgaff/DSCN5021_zpsd6708225.jpg (http://s134.photobucket.com/user/lgaff/media/DSCN5021_zpsd6708225.jpg.html)

Lookin Good Lee!

[Schrade]

How much did resto cost? NOT counting your own time?

Just curious here Mr G; don't disclose if you don't want...


And maybe a little on the frame / airflow tech??? What was the purpose of THAT?
I hope I didn't violate anything, since this is not ZR-1, but I wanted some input. I am starting to see Callaway Twin Turbos coming into my humble price range. I know there are members that must have had or have these cars. I have never owned or drove a turboed car before & was curious of the driving performance.

1988 RPOB2K Performance

382 BHP @ 4000 RPM
562 Torque @ 2800 RPM
0-60 in 5 seconds
0-100 in 12.4 seconds
1/4 mile in 12.8 to 13.7 depends who you read.

I guess there are some pretty simple & effective performance mods with a low restriction exhaust & a Callaway "Wonderbar" (apparently, a less restrictive frame channel for Air Inlet).

Anyway, what's it like to drive one of these cars with, not so much HP & a ton of Torque????? Thanks, Tim

[LGAFF]

Its a long way from being done. Come to think of it I might have paid less than $13K, hard to remember. Might have been $11500

Car ran when I got it, drove it from STL to home. It had an oil leak coming from the trans pan, manifold, and turbo sumps. I ported the heads and put in larger valves 2.0/1.55 Manley race valves.

I then found an intake on ebay for $600 (with injectors and rails) that turned out to be a GM prototype that looks close to the 100 plus. It was intended for a Hi-Po 1LE Camaro, but in speaking to Jim McFarland one of the criteria was to clear the Corvette hood. This intake on a NA L98 stock motor would have made over 300hp per mr. McFarland. its one of 4 made! Jim McFarland was shocked it got out of GMs hands, as it was kept quiet. JOhn Hienrecy(sp) confirmed it was a skunkworks project that got scraped because of the upcoming LT-1 project.

I had a lot of experimenting with the fuel rails to get a workable version, and then issues with the fueling. The car runs but boost is a challenge. I am still not sure about the health of the motor. Compression is 115 across all cylinders(its 7.5:1 compression).

So as I left it last year, car ran, although boost was a struggle, it would hit hard after sputtering, etc. I am hoping to finish it in late 2014(have a 368 LT-5 to build and get sold)


Turbo rebuild: $700(I probably could have done this myself after learning about it.

Porting: free

Intake: $600

Misc fuel rails stuff: $300

Sledgehammer cam: $340

Wonder bar: $450

*Car needs new carpeting it sat out in AZ
*Paint is rough

**Keith Martin said this car would never see the road again because of the mech leaks, etc....out to prove him wrong. :cheers:

[USAZR1]

Lee,does your TT have a 4+3 or 700R4 trans? What's the engine redline on those engines?

[LGAFF]

Its the same redline as the stocker because of the TPI.....in the current setup I should be able to run to 6K+. Engine has a better crank/rods/pistons than stock.


Its got the 4+3

[LGAFF]

Here is the small wonderbar used from 88-91 on stockers....the big wonder bar enlarges the rail creating a larger plenum:

http://i134.photobucket.com/albums/q115/lgaff/DSCN5569.jpg (http://s134.photobucket.com/user/lgaff/media/DSCN5569.jpg.html)

[Schrade]

Do the turbos have any problem getting air through the intake manifold? Any room for improvement there - like porting the intake, or the like???

(L98 intake manifold was designed on flow characteristics of LB9 TPI, and what's why L98 runs out of air @ higher RPM's)

[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]

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)
http://i1202.photobucket.com/albums/bb373/Paul_Schermerhorn/EFIConnection/5f41a0b4-9238-4070-b2e8-3b86acb7636b.jpg (http://s1202.photobucket.com/user/Paul_Schermerhorn/media/EFIConnection/5f41a0b4-9238-4070-b2e8-3b86acb7636b.jpg.html)

[Kevin]

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

[Hog]

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

Yes it's a picture of bigfoot.

[Schrade]

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)

:confused:

[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!!!!