numbers are fine....i dynoed @296/306 w/ borla, & lid which is basically all you have so dont fret.

 

i dynod 303rwhp/318tq
whisper lid, K'N filter, cold air cutout, 160 stat, bone stock exhaust system.

 

horsepower is a product of torque. it takes less torque to move 3.73 as compared to say 3.23 think of it as a ten speed bike. 10th gear takes a lot of energy to move. so now switch to 5th gear. now it takes less energy to move the same object. less energy = less torque which = less horsepower.

 

Gearing shouldn't raise or lower HP thats the whole reason you use the 1:1 gear ratio.

 

Have you been the only owner of the car? With that torque spike it sounds like a converter is in there.

 

dyno showing MPH is common on Mustang Dynos.. What brand of dyno did you use?

Dynojet shows typically higher numbers but are used more often by larger groups as its the most popular so the numbers are easier to compare.

mustang dynos are said to put a load on the car showing a more accurate hp reading.. I have also heard that cars tuned on a mustang dyno seem to respond better.. but my argument with that is that the numbers often generated by a mustang dyno (along with gears and car weight) used to calculate the fastest ET and MPH at the track are way off but when you use the dynojet numbers its more accurate..

 

99snkklr has hit it on the head. 3.73's (or any lower gear ratio) WILL make you dyno lower.

I have a 2001 Z28 with cut out lower air box, lid, ported descreened MAF ends, SLP bellows, catback, Y3000 2.0 STR TC, 3.73's and my dyno numbers are as follows:

SAE corrected dyno jet:

287.5RWHP/348RWTQ

Do not get hung up on the numbers, how does the vehicle run? Mine runs like a scalded ape.

Dyno numbers do not win races.

JMHO

SteveC

 

using the 1:1 takes away the transmission variance. connecting the motor to the rear. stop and think about my reference to the 10 speed. if it takes more effort to move, then you produce more torque which in turn makes more horsepower. and teh opposite when you have a higher gear ratio.

 

I just got mine dynoed (dynojet) not long ago. I asked the tech about what gear is best. He said it did not mater. He proved it by running it in 4th gear, then 3rd. with exactly the same results. He continued to run the rest of the runs in 3rd so you are just spinning to 100 mph. Later>>>>>>>>>

 

So if that's true, then it should also be true that it DOES NOT matter what gears are in the differential. Otherwise, something's f----d up!

I actually would have thought that the lower gear you run in (ie: 2nd vs 3rd, or 3rd vs 4th) the higher power you'd make, which would in essence make it that the lower gear ratio you have, again the more power you'd make, but I guess I'd want to see that all for myself, cause it seems to conflict with what's being said here!

 

Your numbers are okay...with a .99 correction the corrected numbers are a little lower than the actual.

The dyno is a tool not the track so try not to treat is as such too much. Use it to test the mods on your car, which work and which don't. You can't really compare numbers to others because some people might ice down their intake, take out the airfilter, and do all these little tricks to get that last HP. Even fresh oil and spark plugs will give you more power, so it's often a waste to compare other cars within 10-15hp or so.

I'm saying just be consistant in your testing and use the dyno to compare against yourself not others.

BTW...the reason the gear doesn't matter is because the dynojet measures the acceleration of it's drums not anything else. You are seeing real power changes, and there is a cost for faster acceleration. Think efficency, you get faster acceleration from gears but it costs you some power to do it.

 

That's where I'm still not sure about the whole "low gears costs HP" thing?

If torque = work = how much "stuff" (ie: weight) something can move, and horsepower = power = how fast something can perform work, and lower gears make acceleration and the performance of work quicker, then I still think you would see the same or higher RWHP?!

 

Dont worry to much about dyno numbers. Ive ran faster at the track then other LS1s putting out 20-30 more hp then me on a dyno... I dont even like to mention my bone stock/light bolt on dyno numbers and wont go back to the dyno until im ready to get dyno tuned once i get a good cam to match my heads, but my track times however make up for the poor hp/trq im missing on motor and on nitrous my times are better then they should be for what i have done. I dont know what it is about my car. Bad dyno numbers, but great track times. However, id be happy with your numbers, take it to the track and run some 12.80-13.0s as it sits...

I had hypertech on my car to, i never liked the power programming. I just needed it to fix my speedo after i went to higher gears. Thats all its really good for in my opinion. If you want tuneing, do some actual mods and get a dyno tune with LS1 edit, should cost in the same ball park give or take a hundred bucks but paying someone with LS1 edit that knows what they are doing it well worth it..

 

That is true! I have 3.73's in my 95Z, and it dynoed low for all the real mods it has. But it runs like Steve said, a scalded ape! I had to pass a car on the hwy, on the way to the dyno, and I kicked it HARD at about 60mph, and it actually caught a tire at that mph!!! Unreal, but I was disappointed w/ the dyno numbers.

I too, was hung up on the numbers, but that car pulls like mad, and runs incredible!

Try a dyno with the HPP3 power tuning OFF, and then one time w/ it ON, and in 3rd gear both times, and see what you get. I bet you will see a difference.

The last dyno I went to, a guy had the HP on his 89Iroc, yes I know, not a 4th gen, but anyway, he removed it and GAINED 15rwhp. YEP. So, it is worth the shot.

When I removed it from my 95Z about 3 years ago, the car actually SPUN tires again.

Good luck!

 

Same here. I ran within .02 tenths of a 396 LT1 M6 that was pushing over 400rwhp at the 1/8th. Dyno numbers mean nothing.