BuickPower3800
Turbo Buick's Rock!!
- Joined
- Jul 14, 2002
Does any one know what the stock horsepower would be for a 1987 GN? It was rated by the factory at 245, but that number seems a bit low.
Did the GN really crank out 245 hp?
- Thread starter BuickPower3800
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BuickPower3800
Turbo Buick's Rock!!
- Joined
- Jul 14, 2002
So if the factory underated the hp numbers would the torque numbers be acurrate? Its 355 lbs/ft. @ 3000 rpm right?
- Joined
- Dec 7, 2002
torque
is probably much higher than the rated 355. it will be a LOT higher ratio than the h.p.. I would say stock torque would be about 425 lbs. Just guessing though
is probably much higher than the rated 355. it will be a LOT higher ratio than the h.p.. I would say stock torque would be about 425 lbs. Just guessing though
BuickPower3800
Turbo Buick's Rock!!
- Joined
- Jul 14, 2002
Man even 355 is an insane number for a V6 but 400+ way cool! I cant wait to get my GN, ill be seeling my Park Ave. in about 8 months to get the car I always wanted, 1987 Grand National!!
TurboJunky
Fire the Federal Gov't
- Joined
- Nov 5, 2002
No way the engine has 425 ft/lbs torque factory. My TTA dynoed 320hp and 399 ft/lbs torque with a chip, downpipe and no cat. Keep in mind the TTA engines had more factory power than GN engines. Not to mention more boost, different heads, headers, pistons, intercooler and a few other little doo-dads to up power over the 1987 version of the LC2 engine.
The TTA and GN had the same HP with the same boost. The heads are different no better (ask Tom at Champion, he has flown both), neither head can outflow the headers so no gains there, pistons make no more power, (same compression ratios) Intercoolers, I think the TTA's might have had one more row, but the problem with both are the neck, so I don't think the TTA's made it any faster, they just held more air in limbo that couldn't flow out of that bottlenecked, neck. I beleive the TTA is faster due to its extra factory boost, and aerodynamics, and in the case of the GN I beleive a little lighter. I think the Dyno differences of a GN and a TTA on a dyno, both running 16#'s of boost are negligible..JMHO though.
TurboJunky
Fire the Federal Gov't
- Joined
- Nov 5, 2002
I have both and when I got my TTA it was completely original. There's a HUGE difference between the two engines. There's a difference of opinion in the way the heads flow, documentation I've read credits the transverse 3.8 L heads with better flow, if memory serves at least one magazine said 18% better flow. The stock ECM's are programmed differently, the exhaust is different, the fuel pump is better and flows more. The plain fact is that the TTA engine compared to a stock GN engine puts out about 30 more horses. Factory original TTAs dynoed around 301hp whereas a factory orginal GN hit around 274hp. Torque curves should be about the same difference.
It's like saying the GNx has the same power as the GN. The TTA and GNx esentially have the same improvements over the GN engine.
It's like saying the GNx has the same power as the GN. The TTA and GNx esentially have the same improvements over the GN engine.
TurboDiverArt
The Guru Thorn
- Joined
- Nov 8, 2002
Wasn't the factory HP and torque rating at the flywheel? Comparing the TTA and a GN based on a chassis dyno doesn't really do anything in determining what the "real" factory HP and torque numbers were. I always thought GM performance numbers were at the flywheel, not rear wheels.
blackbuick87
Senior Member
- Joined
- Mar 11, 2002
You are correct sir! No way the GN had 275 RWHP
At the flywheel, yes
Art, the problem with GM's #'s are that they lie. GM does do it at the flywheel with all accessories hooked up, so they underrated the GN big time. Now that HP means alot , GM is pretty much on the mark now. The Cobra I think is trying to make up for the 2001 fiasco of overrating the HP by underrating the HP of the 03 Cobra.
I still think that the factory HP #'s of a TTA are closer to 290 HP and a GN running 16 psi would be around the same. You quoted the GN at 275 stock w/ 14 psi and 1# of boost ='s 10hp, so that would put it at 295, and I'd think you would even agree that 6 hp more is negligible.
I still think that the factory HP #'s of a TTA are closer to 290 HP and a GN running 16 psi would be around the same. You quoted the GN at 275 stock w/ 14 psi and 1# of boost ='s 10hp, so that would put it at 295, and I'd think you would even agree that 6 hp more is negligible.
TurboDiverArt
The Guru Thorn
- Joined
- Nov 8, 2002
No disagreement there Scott. The old HP numbers were like MPG ratings...
BuickPower3800
Turbo Buick's Rock!!
- Joined
- Jul 14, 2002
If a GN put 275 hp to the ground then wouldnt the rating at the flywheel be around 310 hp?
Dont rear drive cars loose about 30% of power between the flywheel and the rear wheels?
Dont rear drive cars loose about 30% of power between the flywheel and the rear wheels?
T
TTA89
Guest
Then why will a TTA WASTE a GN at the track if both are factory stock running 16psi? Aerodynamics? Doubtful that it makes that large of a difference.
Everyone always talks about the Flow of the GN and TTA heads, what about the design? Take a look at them, they are TOTALLY different. Did anyone ever think that maybe the different design of the TTA heads allows them to make more power????
Take a GN and TTA, do the basic Reciepe Mods and keep the Stock Turbo, IC, Injectors, DP ect ect and see how far ahead the TTA is. Most people believe a TTA is 3-5mph ahead of a GN with the same mods. I can't beleive aerodynamics make THAT big of a difference at those speeds.
On a Dyno? I dunno.. I don't care
I don't race on the dyno or really care how much power my car makes. As long as I stay ahead of the other guy that is all that matters to me.A TTA is probably 270-280 at the wheels, it weighs more than an LS1 does.
Who cares anyways... Are there really Stock GNs out there? God I hope not... They'll make us look bad at the track
I'll stick with my feelings. I agree it doesn't really matter, there are no more stock GN's at least racing anyhow. The reason why I bring up the dyno is because we are talking about driveline hp and both vehicles at 16psi, i beleive are extremely close.
Yes there is a loss through the driveline, that is why my WS6 was rated @ 325hp and was in the 290's rwhp. I think the Gn was closer to 310 fwhp which is way more than the 245 fwhp that GM claimed. Still, JMHO though.
Yes there is a loss through the driveline, that is why my WS6 was rated @ 325hp and was in the 290's rwhp. I think the Gn was closer to 310 fwhp which is way more than the 245 fwhp that GM claimed. Still, JMHO though.
I'll admit I don't know where the heads came from, but didn't Buick just pull them off one of their other motors???
Oh, and a better desighn would have to mean better flow. Flow is what makes you go. aka ,A better desighned head would be a head w/ better flow.
The ? of aerodynamics between a TTA & Gn were brought up a while ago on another board. Based on someones math, a TTA uses approx. 54 hp to just cut the air at 100 mph, 28 hp is needed at 80 mph. This is based on frontal area and CD rating.
TTA's CD is .31 which is the same a Lamborghini Diablo. Wasn't any info for a G body, but I doubt its CD rating is even close, so aerodynamics do account. my useless $.02
TTA's CD is .31 which is the same a Lamborghini Diablo. Wasn't any info for a G body, but I doubt its CD rating is even close, so aerodynamics do account. my useless $.02
Rogue Leader
Eat my valvestem caps!!!!
- Joined
- May 25, 2001
Just FYI ... a STOCK TTA put down 301 at the rears on a GM dyno... (many original TTA documantation points this number out) as for 245 HP in the 87 GN that was an arbitrary number and totally meaningless, 245 came from the fact that the 87 Vette was rated at 255 HP. Just as the 89 TTA's 255 HP rating because the 89 Vette was factory rated at 265 HP.
