Super Chevy Muscle Car Dyno Wars

[Scott Liggett]

I'm sitting here reading the Feb. 2011 issue of Super Chevy and they are throwing stock muscle cars on their DynoJet chassis dyno. I have to say that I am a bit surprised by the low hp numbers pumped out by the LS6, TH400 Chevelle and the Yenko 69 427 Camaro. 285 and 287 hp respectively. And, both pulled just under 320 ft lbs of torque.

I know that different dynos show different results, but I had my Impala on Westechs Dynojet and it's 383 pulled 320 hp and 360 ft lbs of torque at the wheels with way too heavy solid roller spec valve springs.

Now, the examples pushed out the dealerships had extremely tame tune ups for reliablility. Ones that got better jetting and timing recurves were putting down mid 12's, with slicks, low 12's. Most mag testing of the cars were right in the mid 14 seconds, where my car runs.

The third car tested was a 57 Chevy with the 245 hp 2x4 bbl 283, PG. It pulled 158 hp and 195 ft lbs of torque. I think the PG had been reworked during the car's previous custom, modified life.

[Bamfster]

Re: Super Chevy Muscle Car Dyno Wars

It struck me as odd too Scott.

I've never had the chevelle on the rollers, but according to the good ole Moroso speed/power calculator, it's only putting out 380 ish with the et and mph it runs.

[DanStokes]

Re: Super Chevy Muscle Car Dyno Wars

My 'Stang is right at 300 RWHP, Dynojet. Runs high 13's on Drag Radials and a 3:55 gear - and it's pretty porky (haven't weighed it but it's a convert with A/C and all and a 6 point cage.

Those old muscle cars really weren't as fast as our memories of them. They're still WAY neat and I lust after each and every one of them.

Dan

[SpiderGearsMan]

Re: Super Chevy Muscle Car Dyno Wars

just need a tuning
some of those automatic trans are slipping , the exhaust systems are restrictive , the tires are soft , the gears are wrong

[A/Fuel]

Re: Super Chevy Muscle Car Dyno Wars

They mesured the hp as SAE net back then and changed it to gross with the accesorys in 1971 (i think) so that will knock of a few, plus a few more when it's on a chassis dyno.

I wonder how they would have rated a 1987 Buick Grand National in 1970?

[dieselgeek]

Re: Super Chevy Muscle Car Dyno Wars

Dynojets are inflated numbers. Westech has a Superflow which actually puts out lower numbers than the Egojet :-)

The problem with the above shootout is, s Spidey points out, transmissions and torque converters are a *HUGE* factor. 3000 lb cars can make 500hp at the rear wheels on certain dynos, and run in the 9s while others can make 1000+ and not go faster than 11s. Unlocked converters KILL power numbers at the wheels.

Meanwhile, the numbers reported are what I'd expect. I kinda doubt any of the OEM cars listed above could run in the low 12s with just a tuneup. Old cars were all slow, period. Fast for their day, yes - but by today's standards, slow. No disrespect intended, except to the "that guy" who thinks his showroom-stock 426 Hemi made 800hp from the factory and pulled the front wheels in 2 gears. lol

Also, gearing won't affect numbers on the dynojet(some have tried to claim it does, but it didn't when we tested it many times) unless it causes tire slippage. However, tire pressure can be a big factor. Is this article online anywhere I can read it?

[Bamfster]

Re: Super Chevy Muscle Car Dyno Wars

I agree with all of that, I just thought that the Yenko or LS6 would have showed something in the low 400 range, since all the claims from back in the day were that their supposed 450 hp was conservative "for insurance reasons".

I guess my point is more of a wow factor insomuch as those cars weren't really all that everyone remembers them to be.

[dieselgeek]

Re: Super Chevy Muscle Car Dyno Wars

I agree with all of that, I just thought that the Yenko or LS6 would have showed something in the low 400 range, since all the claims from back in the day were that their supposed 450 hp was conservative "for insurance reasons".

I guess my point is more of a wow factor insomuch as those cars weren't really all that everyone remembers them to be.

I think that was all marketing BS, honestly.

I just do not see any stock oldschool combo putting down much more than 200whp without a lot of work. (that's 200 SAE hp, or somewhere around 250hp in Dynojet numbers)

[Bamfster]

Re: Super Chevy Muscle Car Dyno Wars

Which reminds me of a guy several years ago. He cloned a LS6, said it made over 700 hp. He showed up to a Super Chevy show and ran 16's, my mild small block was running mid 13's ....

It's amazing what we took for gospel back then.

[Scott Liggett]

Re: Super Chevy Muscle Car Dyno Wars

I remember reading articles on stock, restored musclecars in a mag where they quoted quarter mile times from original magazine testing of these cars when new, Car Craft,Motor Trend, etc. Most every big block car ran in the 14's. The one exception was the ZL1 Corvette than ran in the low 13 's. Hemi, LS6, Super Duty, Stage 1, Super Cobra Jet were all the same.

Somewhere I have a calculater that if you punch 1/4 times, trap speed, vehicle weight and such, it will give approximate hp numbers. I imagine with the tires the cars came with back then the 60 ft times were horrible.

[SpiderGearsMan]

Re: Super Chevy Muscle Car Dyno Wars

not getting traction from those junk tires was a big problem

[TheSilverBuick]

Re: Super Chevy Muscle Car Dyno Wars

Sweet, my 5,000lb Centurion is quicker than a 700 horse LS6 car :D

[Bamfster]

Re: Super Chevy Muscle Car Dyno Wars

He even borrowed a set of ET Drags ....

[dieselgeek]

Re: Super Chevy Muscle Car Dyno Wars

not getting traction from those junk tires was a big problem

didn't really need much out of the tires when you're putting a whopping 200hp through them. lol

[SpiderGearsMan]

Re: Super Chevy Muscle Car Dyno Wars

guess these40 year old engines aren't worn or anything


the only guy I know who had a legit muscle car was artie and his L88 68 corvette , he said he ran an 11.50 at maple grove in 1971 , just slicks as a mod
then he detuned it