Do any of you guys think that the horsepower ratings of this car were underrated. Correct me if I am wrong but the 3.8 L was rated at 250 hp at the flywheel. This car also weighs around 3300 lbs. Not exactly a light car for the power. These cars are said to run 13.4-13.8 thats pretty fast, 13.4 is what the WS6 cars run. I would think the Horsepower would be 250 at the wheels to put down those numbers not at the flywheel!

To get to my question has anyone who owns one of these had it dynoed? Thanks.......

[Saw one beat an ls1 in a street race] now I am curious

 

Heres my thread below..

https://www.thirdgen.org/techbb2/sho...hreadid=328093


THe TTA was rated 250hp but was underrated. But really they were rated little over 300hp at the flywheel. I guess they didnt want to make the corvette look bad, esp the fact its just 3.8 V6.

 

Yes, very underrated. And the rating had nothing to do with the Corvette's rating either since it was already rated higher.

 

Not really... What by 5 hp.... The 89 Vette was 245hp and the TTA was 250.

 

Ya, I thought that GM underrated them as they do with a lot of there engines, LT1, LS1, ect...Anyone else think they underrated them beacuse they didnt want it to be above the Corvette performance level?

 

Dont we wish our L98s were underrated! They did have some factory freak L98s though. They were L98 vettes hitting high 13s stock.

 

Did this car ever beat that wicked fast turbo Buick Regal car they had back in the late 80's?

 

They had the same motor with a few little tweaks here and there

 

Yeah, it was faster

 

Wasn't the GNX quicker than the TTA in the 1/4?

 

A GN would run high 13s to low low 14s. A TTA would run mid 13s. Was probably lil lighter and was 10x better handler/aerodynamics as well. And cooler looking

 

Although extremely rare, a couple ran 12.9 completely bone stock. Most TTA's were in the 13.2-13.4 range, providing you left on some boost. The 14 second magazine cars were leaving at idle.

Mine ran 13.01 with a 8" K&N cone filter and thermostat. With a MAF pipe, 1 screen out of MAF, cat pipe, Thrasher92 chip, 18psi of boost, and drag radials I was able to run a 12.1. The stock injectors were static, the stock downpipe was choking it, as well as the stock suspension. Although I did cut a 1.65 on a completely stock suspension with only drag radials.

The cars are incredibly easy to make fast

LS1's were under rated but LT1's weren't. My 96 WS6 dynoed at 274rwhp when stock, which comes right at the 305 it was rated.

 

Yours was rated 274rwhp stock? a 96? Which means you have a LT1. LT1s were rated 275hp on the early models and the later models were 285 hp? But you say it makes 305 at the flywheel? I thought LT1s werent underrated??! LS1s came into the Fbody in 1998..

"LS1's were under rated but LT1's weren't. My 96 WS6 dynoed at 274rwhp when stock, which comes right at the 305 it was rated."

 

LOL,I understand what you said Rob.Nick,read his post again

 

Sorry Rob and Steve. I feel like a moron... But i still dont understand??

 

96 WS6 was rated at 305hp. 20hp more than the standard LT1 in the Z28 and Formula/Trans Am.

 

REALLY? I never knew that! Thanks for the info. I though it was rated 285hp in all the LT1s in 1996. Thanks though, sorry i didnt know about that. Do you know if theres any reasons why it was 305hp? Maybe they added LT4 parts into it? Also was a base LT1 vette in 96 rated 300hp or was that underated? I know Lt4 came out in 96 (only year) and made 330hp at the flywheel.

Also what about the 1996-1997 LT1 Camaro SS? Were those rated 305hp or were they like a Z/28/ Formula/TA ?

 

It was a standard LT1 that got a different induction package. You got the Ram Air hood feeding into an air box. Then into a MAF, right into the TB. It was very short and straight. So it was basically a factory cold air package to get the HP rating.

Suspension was different. 17" wheels, different sway bars, shocks/struts, and bushings.

Everything else was identical except the exhaust tips were oval.

My car went 13.50@105 bone stock the only day I had it at the track, at least in bone stock trim.

The SS was rated at 305 also, but it didn't run like the WS6. The air box sat right over the engine and basically had to do a 180 to the TB.

SLP did the WS6, SS, and Firehawk. 98+ WS6 was done by ASC.

 

Ahh i see now. I never knew they were rated 305hp. I thought they were rated 285. Very intresting. Is this what you're talking about?

 

Hey TTA owners how easy is it to get mods for these cars?

 

Easily enough

 

Here's an old engine dyno of one back in 89

 

GM underrated the output to bypass the gaz guzler tax, so I heard.

I also heard some LS1's put out 300hp at the wheels ..

 

Underrated because GM-Hydramatic wouldn't warranty the 200-4R tranny with over 250 hp. So another rumor goes.

 

I was wondering about the GNX vs. TTA, not the regular GN. All are awesome cars in my opinion.

 

That is a picture of the SS.

Here is a picture of the WS6 setup.

 

Tranny warranty, not gas.

Most stock LS1's put out 300 to the wheels. Even the GTO put out that thru an independent rear.

Camaro/Firebirds were under rated. GTO's were rated right where the F-Body should have been 350/365. The GTO engine is identical to the '01-'02 F-Body LS1. Same everything except exhaust manifolds.

 

Yep ive seen these b4. I never knew those were factory. I thought they were an aftermarket kit or somthing. I like those 96 Ws6 and 96 SS. Cool cars. Also if those are your cars, thats one sweet collection. Jealous

Yes the GNX was made in 87 only i believe (last year) They were tad quicker then the regular GNs and would his mid 13s. I still think the TTA is the better overall car.

 

SSs and WS6s were rated correctly. Every LT1 without exception will put down that much power. Some are a little freakier.. like mine..

 

On that dyno sheet it says ghp does that mean Gross hp. If so does gross hp just mean at the flywheel? not sure i though that was how they use to rate old muscle cars not sure though

 

Motor Trend did a head to head back in 89. The GNX won the first two and then the TTA driver figured out how to launch the car and beat the GNX by a nice amount.

 

Thanks. I'd love to see a tape of those runs!

 

Same here!!

 

I might have it. I know I have seen it. Don't know if I saved it though. It was a long time ago

 

http://www.gtasourcepage.com/89ttagnxshootout

 

Did they have a manual? Or just Auto trans?

 

Just the auto.

 

The tta was underrated, they also tested the grand national against the vette and the grand national smoked the vette by a second even though the power was rated the same. If you are looking for a TTA I saw one for sale today in East Saint Louis, Ill at gateway classic cars it only has 4400miles on it! They were asking $23k for it. They also had a 30th anniversary TA.

 

Huh? Smoked the Vette by a second? A regular GN was a high 13 second car and low 14 sec car (non GNX) A corvette will run similar times to the GN. L98 vettes ran high 13s (some) low 14s. Plus the vette weighed 3200lbs. A Gn weighed what? Same as a thirdgen? The weight on the vette helped alot.

 

My 87 GN ran 14.2 completely stock back in '88. This compared very well with my buddies '87 IROC 350 that ran 14.3 on the same day. Also bone stock.

Stock cars back in the day were very close. Whether Mustang, Vette, F-Body, or GN.

Add a paper clip to the GN and you could run 13.9 easily. The Buick turbo V6 was/is incredibly easy to make fast. Less than $500 and it will be in the 12's all day long

 

Just remember a magazine testing a new vette against a new GN and the GN beat it by a second. Obviously the GN should lose if the HP was the same, therefore you would think the GN and TTA HP ratings were not correct. I guess the GN could have had a traction advantage at the dragstrip. Don't remember the MPH they ran in the 1/4, a good indicator of HP regardless of ET.

 

my bone stock auto TPI Vette (3.07 gears) went 13.9 at 99mph with a low 2.0 60ft

i would think the TPI Vette would have the traction advantage with its 255/50ZR16s (85-87), or 275/40ZR17s (88-91) versus the GNs pizza cutter 215/60R15 tires. put some sticky tires on them, however, and the GN would have a clear advantage out of the hole with its better gears (3.42s) and the ability to now launch on boost without spinning

 

Maybe so, but the GN might have better weight transfer and distribution. I wouldn't call the tires it had pizza-cutter.

 

Gears are better on the GN. 215s? Man those things are skinny. Compare those with just the 255s on a early C4 and the tires are much wider and thats 255s are 4 wheels. Then the later 80s came with the 17 inchers that had the 275s like mentioned. Plus the vette will outhandle a GN like nothing. Clearly they are both awesome cars. And the GN responds mods awesomely. I think there both diffrent cars with awesome potential C4 vettes are the cheapest best vettes to get now (like thirdgens) GNs still have high value tho. I wish i had one. Sweet cars for sure.

 

I think some people are thinking GN and others are remembering the GNX.

Although the GNX had only a few modifications over the stock Grand National, keep in mind that the 87 GNX was the fastest American production car (0-60) for '87 and held that title for several years after.

 

only reason being is because RPO coded Vettes weren't tested


RPO: B2K
Type: turbocharged and intercooled V-8, iron block and aluminum heads
Bore/Stroke: 4.00 x 3.48 in., 101.6 x 88.4 mm
Displacement: 5,733cc, 350 cu. in.
Compression: 7.5:1
Engine-control system: GM/Chevrolet electronic engine control system with port fuel injection and Callaway Micro-Fueler
Emissions controls: 3-way catalytic converter, feedback fuel-air-ratio control, EGR, auxilliary air pump
Turbochargers: 2 Warner-Ishi RHB 52W
Waste gate: integral
Maximum boost pressure: 10.0 psi
Valve gear: pushrods, hydraulic lifters
Horsepower: 345 bhp @ 4,000 rpm
Torque: 465 lbs. ft. @ 2,800 rpm
Redline: 5,500 rpm

you could order this car from GM but since it was built out of house i guess it didn't make the car mags as the quickest GM car for 87


and they only got better

http://www.corvetteactioncenter.com/specs/callaway/

 

They did........ Callaway lost. Plus < 200 units doesn't qualify it as a production vehicle.

 

OWNED!

 

They consider them supercars huh?

 

alls that mag test proves is that they couldnt drive the Callaway worth a crap. theres no way an almost 400hp/500tq Vette only traps 106mph. the boosted Vette was an easy mid 12 sec car at at least 110mph. people have proved this on www.corvetteforum.com with stock examples at the strip