245 or 250 HP, what the...???

[slapshot]

OK, I need some help figuring out why some resources rate the hp of a 91 L98 at 245 and some 250, even the CAC info has both 245/250 HP ratings. What gives??

 

[Edmond]

OK, I need some help figuring out why some resources rate the hp of a 91 L98 at 245 and some 250, even the CAC info has both 245/250 HP ratings. What gives??

If I recall correctly, the convertibles had 245 due to more restrictive mufflers for noise control purposes.

 

[Matt]

http://www.idavette.net/facts/91.htm

check that place out, it lists both ratings maybe you can figure it out with that site

 

[G Winter]

AHH so min. 5 hp gain by eliminanting the mufflers?

 

[Edmond]

AHH so min. 5 hp gain by eliminanting the mufflers?

Probably more than that because the stock mufflers only flow out of one tip.

 

[G Winter]

not to mention the weight savings

 

[Edmond]

not to mention the weight savings

Definitely! The mufflers have to weigh 20-25 pounds each. If you take off the spare tire and the carrier, that's another 25 pounds. Every 100 pounds of weight taken off shaves .1 off the 1/4 mile.

 

[slapshot]

Thanks for the info, I kinda figured it was something like that.....but even the info on te idvette site has 2 ratings, and no reason why...

ZTA: 350ci 245/250hp ATZTC: 350ci 245/250hp AT, OC ZTB: 350ci 245/250hp MT, OCZTK: 350ci 375hp

 

[c4cruiser]

The difference in the mufflers was for sound control; the vert had quieter mufflers so the added baffles restricted the flow and reduced HP. The engines were identical.

 

[Matt]

now that i think of it, its a better idea just to go get it dyno'ed for a better idea of what its really putting down. regardless of the 5 hp difference, there's no need to worry about a manufacturer crank hp rating anyways.

 

[Edmond]

now that i think of it, its a better idea just to go get it dyno'ed for a better idea of what its really putting down. regardless of the 5 hp difference, there's no need to worry about a manufacturer crank hp rating anyways.

Very true. You can never assume anything. GM has been known to have some variations in hp output so you never know.

Are you going to start hotrodding it and see how much you gain?

 

[I_R_DA_ONE]

Horse power

Edmund
YOu are correct about the HP rating of GM motors....
IN the lat 60's and early 70's GM under rated most all thier preformance motors because of insurance.....a prime example was the L-88 which was rated at 430 HP when everyone knew that it had way over 500 HP....
My little ole 86 doesn't have but 235 HP but it does just fine for me,,
I know this was mostly usless information but still nice to know..

Mike

 

[Edmond]

Edmund
YOu are correct about the HP rating of GM motors....
IN the lat 60's and early 70's GM under rated most all thier preformance motors because of insurance.....a prime example was the L-88 which was rated at 430 HP when everyone knew that it had way over 500 HP....
My little ole 86 doesn't have but 235 HP but it does just fine for me,,
I know this was mostly usless information but still nice to know..

Mike

I would bet that even the current LS2 motors are underrated. I wouldn't be surprised if almost every motor out there by most manufacturers was slightly underrated due to the 99' Ford Cobra fiasco where they overrated the horsepower. I think they advertised 320 and most were coming with 290.

 

[G Winter]

It would be intresting to see results of a GM supercharged 3800 . I had one in a 98 Riv. and it would do 0 to 60 in just over 7 seconds. 3900 lbs with one person in the car. I felt at 245 hp the engine was underated. I wanted to take it to the strip just to see 1/4 mile times but sold it before I got that done. Often thought that the supercharged 3800 would make a great little rod engine. Some exhaust and computer tweeking who knows . 300 hp +

 

[JRMaroon]

I had one in a 98 Riv. and it would do 0 to 60 in just over 7 seconds.

Fun motor. I had a '97 GTP Grand Prix that would hit 60 in under 7 seconds and chirp second in Sport Mode. I never took it to a track but I did surprise a few 5.0 Mustangs with that car.

Jeff

 

[G Winter]

Just think , that engine tranny in about a 2600 lb car with a little tuning and exhaust. Wasn't passing a rush ? Dropping from OD TC locked to second gear, you didn't want to be riding anybodys tail. Not so sure that in the 1/4 mile it wouldn't run close to my vette.