why low stock dyno numbers?

[jtbball]

i was interested in purchasing a 1998 z28 m6 and it was dyno'd stock at 267 rwhp i know it was on a mustang dyno but it thought it should be 300. just wondering if i should be concerned about the engine or have any reason not to by it... he said it was on a hot day with the ac on?

[oneBADDz]

#1 why would they dyno with the a/c on?
#2 that's not bad for a mustang dyno, don't worry about anything solely based on those numbers

[98LSGUN]

Stock Z's only had 300 at the fly I think. Sounds about right to me :dunno:

[senicalj4579]

Stock Z's only had 300 at the fly I think. Sounds about right to me :dunno:


so when gm says,1998 z-28 has 305 hp, they mean at the flywheel and not wheels? if thats so,what are the usual hp #s for a stock 98 z-28 with 305 hp?

[jtbball]

#1 why would they dyno with the a/c on?

girlfriend dropped it off or something....i just dont want it to be behind 20-25 hp no matter what i do to it...i also heard that once u start modding the stock numbers dont mean much any truth?

[oneBADDz]

girlfriend dropped it off or something....i just dont want it to be behind 20-25 hp no matter what i do to it...i also heard that once u start modding the stock numbers dont mean much any truth?
There really isn't wrong with those stock numbers. If it were a dynojet you would have put down around 300hp at the wheels. The reason mustang dyno #s are lower is because they load up the rollers and simulate a more streetlike situation by putting resistance on the wheels. dynojet rollers spin freely.

[BrandonDrecksage]

every dyno is different...a car magzine tested something like 12 different dyno shops in nearly same conditions and came up with a 70hp difference between them.... dynos are only good for seeing how much you gained with a mod..not really with how much a car puts out.

[awsomford]

On mustang dyno's give real results where normally chevy guys use dynos that inflate thier hp numbers yours truly chevy's suck

[mavrikZ]

You just like them because they say Mustang. Like every other conveluted "overhead-scam" shit box on the road.
260HP---"thats sooo cute":lol:

[jimbo98z]

On mustang dyno's give real results where normally chevy guys use dynos that inflate thier hp numbers yours truly chevy's suck
:itsok: We know you guys wish you could make 300 stock on any dyno. Everybody just uses the dyno they have available. When I went to dyno my Camaro, it was at a place that specialized in Mustangs, yet they had a Dyno Jet, so the Mustang guys were "inflating their hp numbers" too.

BTW: Where did the :troll: smiley go?

[oneBADDz]

On mustang dyno's give real results where normally chevy guys use dynos that inflate thier hp numbers yours truly chevy's suck
dude seriously, put a stock gt (pre-05) on a mustang dyno and you'll get high 100s to the ground won't you? :Ohno: you say chevy's suck :dunno: Even on a mustang dyno we put more to the ground that you have at the flywheel

[jimbo98z]

I said this on the thread with "awsomford"'s other post, but here goes again:
Can we ban this tool? All he does is pop in, say Chevy's suck, and then leave.

And where did the :troll: icon go?

[senicalj4579]

I said this on the thread with "awsomford"'s other post, but here goes again:
Can we ban this tool? All he does is pop in, say Chevy's suck, and then leave.

And where did the :troll: icon go?


where did he go? he went to suck off all his mustang freinds. :gay:

[jimbo98z]

careful there senical, don't want to turn it into multiple bans. Just trying to do it without starting some shit...

But this is what I have to say to him:
http://i82.photobucket.com/albums/j277/jimbo98z/williecares.jpg

[97z286speed]

anything under 290 for an ls1 is low. they were underrated from the factory to make the vette look better, after all it is 20k more.

my stock m6 ls1 put down 308, which is about right.

267 is pathetic and somethings obviously wrong

[oneBADDz]

anything under 290 for an ls1 is low. they were underrated from the factory to make the vette look better, after all it is 20k more.

my stock m6 ls1 put down 308, which is about right.

267 is pathetic and somethings obviously wrong
read the thread, there are two types of dynos, they give two types of numbers. Put his car on the dyno you ran on and he would have VERY close numbers to what you made. Don't call his numbers pathetic when you have all the info you needed to know what the deal was right here in this thread.

[senicalj4579]

so when gm says,1998 z-28 has 305 hp, they mean at the flywheel and not wheels? if thats so,what are the usual hp #s for a stock 98 z-28 with 305 hp?


hey onebaddz, do you have an answer for this bro?

[oneBADDz]

hey onebaddz, do you have an answer for this bro?

they rated it as 305 at the crank, but realstically they put down that much at the rear wheels. 98s tend to be slightly less than the later years and some only put down 29x. 2002s sometimes tend to put down 310-315 at the rear wheels. So rated at 305 at the crank they actually make 320-sometimes 340 at the crank. There's an article a few people have posted on here from a magazine that dynod a 99 fbody and a 99 corvette when they were brand new and the fbody actually put more power to the wheels than the vette did.

[jtbball]

so basically theres a discrepency bc there are several different types of dynos that give different numbers. 267 is pretty low even if it is a mustang dyno and might be a little higher if the ac was off.
basically my question is should i still by this car and if there is something wrong with it what would it be

[oneBADDz]

I really don't think you have a problem with the numbers. I wouldn't be scared off just by them. Have you driven it or anything? Even if the numbers are a little low it probably just needs some basic maintenance, but you should rely on what you get out of the car when you drive it and check it out in person more than anything

[jtbball]

thanks that sounds exactly like what i was thinkin hopefully with some ignition components and filters and fluids it should be back up there but ill be able to tell when i give it a drive

[97z286speed]

read the thread, there are two types of dynos, they give two types of numbers. Put his car on the dyno you ran on and he would have VERY close numbers to what you made. Don't call his numbers pathetic when you have all the info you needed to know what the deal was right here in this thread.

i DID read the thread and my car was dyno'd on a mustang dyno, which is one of the more accurate types even for fbodies belive it or not. now i know all dynos will have number differences due to conditions and what not but 267 IS extremely low.
on a mustang dyno, he should have been at around 305 assuming everything works properly and the general maintainence has been performed.

[oneBADDz]

i DID read the thread and my car was dyno'd on a mustang dyno, which is one of the more accurate types even for fbodies belive it or not. now i know all dynos will have number differences due to conditions and what not but 267 IS extremely low.
on a mustang dyno, he should have been at around 305 assuming everything works properly and the general maintainence has been performed.
You don't understand how the different dynos work, his numbers are good for a mustang dyno. If you dynod 305 on a mustang dyno than they corrected the numbers to match those of a dynojet, which is not necessarily unusual for places with mustang dynos. 267 is normal for a mustang dyno of an fbody. If you were to actually dyno 305 hp in mustang dyno numbers you would be making like 375 hp at the crank.

[mavrikZ]

i DID read the thread and my car was dyno'd on a mustang dyno, which is one of the more accurate types even for fbodies belive it or not. now i know all dynos will have number differences due to conditions and what not but 267 IS extremely low.
on a mustang dyno, he should have been at around 305 assuming everything works properly and the general maintainence has been performed.

There is no way a stock F body will make 305 on a Mustang dyno, unless you got one helluva freak.:dunno:

[redz284u]

correct me if im wrong, but rule of thumb on a mustang dyno is add 15-20% and u get the jet number.....thats what i found out when i got my dyno sheet from a mustang dyno......it came down to how i was sizing up at the track....i was running 13.5- california speedway, almost same as the "others"...regardless of what the dyno reads out as long as i keep beating 06 gt's im good.....

[mavrikZ]

Exactly^. If you ask any reputable Dyno shop, Mustang or DynoJet, they will tell you the same. The numbers he made are good for a Mustang:yup:

[Liquifire]

so basically theres a discrepency bc there are several different types of dynos that give different numbers. 267 is pretty low even if it is a mustang dyno and might be a little higher if the ac was off.
basically my question is should i still by this car and if there is something wrong with it what would it be
considering it was hot and had the AC on ...........the numbers are OK and you should not be concerned with it just because of the numbers.........buy it if the price is right.

[jtbball]

what u all think the right price is? i was thinkin 8000
1998 z28 m6 80k t-tops cloth good cond

[senicalj4579]

sounds about right. although you and i both know theres gonna be some critics telling you to find better,i would take it.

[mavrikZ]

Sounds like a helluva deal to me! Do it!

[tx77015ls1]

316 hp on a Mustang dyno with 93 octane gas and mods in sig mius the SLP smooth bellows

314 HP on dyno jet with 87 octane gas and smooth belows

never dynoed it stock but it did 13.5@102 stock

[Bob'sWS6]

i was interested in purchasing a 1998 z28 m6 and it was dyno'd stock at 267 rwhp i know it was on a mustang dyno but it thought it should be 300. just wondering if i should be concerned about the engine or have any reason not to by it... he said it was on a hot day with the ac on?

Based on those numbers that car is probably pushing a little over 285whp, which is normal for that model year. The 01-02's dyno slightly higher, but aren't that much quicker.

[skar]

You don't understand how the different dynos work, his numbers are good for a mustang dyno. If you dynod 305 on a mustang dyno than they corrected the numbers to match those of a dynojet, which is not necessarily unusual for places with mustang dynos. 267 is normal for a mustang dyno of an fbody. If you were to actually dyno 305 hp in mustang dyno numbers you would be making like 375 hp at the crank.


On a mustang dyno I got 303 rwhp with slp lid and loudmouth .
336 rwhp with ls6 intake kooks headers off road y-pipe(catless)
and a magmaflow and tune (loudmouth sound like shit with headers)
???? so what would I be on a dyno jet. ? :thinkin: + 10%
thanks

[Bob'sWS6]

On a mustang dyno I got 303 rwhp with slp lid and loudmouth .
336 rwhp with ls6 intake kooks headers off road y-pipe(catless)
and a magmaflow (loudmouth sound like shit with headers)
???? so what would I be on a dyno jet. ? :thinkin: + 10%
thanks

I've read that the mustang dyno typically reads 15% less. I dunno for sure though, and also some of the new dynojet's are recalibrated to use load on a car, like the Mustang Dyno.

Considering your mods most people see over 350whp tuned, so i'd figure somewhere above there. It ain't what you put down on the dyno, but what you do at the strip.

[RRev Tim]

I own a Dynojet and have had many stock Camaros on it, including two of mine (98 and a 00) They all seem to put down anywhere between 300-310 at the rear wheels.. That is SAE correction. If the car is putting down 260 something AND its a 6 speed it is a little low, if its an auto, sounds about right.

[PEWTER Z]

I just got my 99 Z28 dyno tuned on a Mustang Dyno, and managed to do 300 RWHP, and 289 RWT after having LT's, ORY, and a Hooker catback with cutout. I also have a a4 with a stall, and went to the track the next day and ran a 12.56 @ 108 in the 1/4, a 7.98 at 85 in the 1/8, with a 1.72 60'. My Z28 also has 116,000 miles on it as well. Your timeslips should be more important than the dyno numbers.

[tx77015ls1]

I did 314 HP and 327 Ft lbs torque ona Dynojet with 87 octane gas


2000 Z28 A4 94,000 miles

[sgt0704]

i was thinking maybe they were running 87 octane. i notice a difference between the 87 and the 91 octane. but i haven't had it dynoed. i would think if the ac was on with 87 octane, that it could make the car run lower.

[oneBADDz]

the a/c has a WOT switch though

[skar]

I just got my 99 Z28 dyno tuned on a Mustang Dyno, and managed to do 300 RWHP, and 289 RWT after having LT's, ORY, and a Hooker catback with cutout. I also have a a4 with a stall, and went to the track the next day and ran a 12.56 @ 108 in the 1/4, a 7.98 at 85 in the 1/8, with a 1.72 60'. My Z28 also has 116,000 miles on it as well. Your timeslips should be more important than the dyno numbers.
wow good run ? street tires or drag.

[2000z28]

when i got my 2000 z28 dynoed, it dynoed with a chip and exhaust at 287 whp, and my friends brand new c6 dynoed at 330 whp, does that sound right, i believe this was on a dynojet by the way, does anyone know if those are normal numbers

[PEWTER Z]

wow good run ? street tires or drag.


Skar,

My run was made on BFG DR's. 255/16's actually. 2 years old and almost bald. The track was hooking quite nicely that night too. Alot of people were having great 60s, but they were off by as much as .4 on their usually 1/4 times since the air was hot and muggy.

[cjg454ss]

i have an 02 ss, 345 hp package plus free mods and polished tb and i put down 349 at the wheels on a mustang dyno. ive never heard of an ls1 making that low.