FLM1

Just hang tight. I'm trying to find a math formula so you cam take your car to the track and calculate hp by your time.

NJHK

You having an auto means nothing...you not being able to lock it in gear is the problem. I have an auto and have dyno'd before and have never gotten anything off the wall like that before.

You need a gear that will allow you to see your whole powerband, not just part of it. Whether you think 4th gear is accurate means nothing because you can't even see your whole powerband. You might be making 155 lbs of torque at those RPMs but say you're making 140 whp at 5500 RPMs, you wouldn't know because you're hitting your limiter.

From my experience and seeing alot of dynos, 98 is way low for a 4-speed 2.2 Automatic, you're looking in the 120 Range stock and should go upwards as you modify.

FLM1

If youhave a quarter mile slip and know the weight of you're car, you can log on to smokemup.com and register and they can calculate you're horsepower from there. I'll try to post a link.

http://www.smokemup.com/auto_math/hp_mph.php

Or try,

http://www.speedworldmotorplex.com/calc.htm

NJHK

Those aren't accurate.

Track times have more to do than just how much power you have.

biohazard

another key variable being reaction time... wheel hop.. u know stuff like that

FLM1

It'll be a hell of a lot more acurate than a dyno run that max's out at 3500 rpm, when your peak hp is close to redline. if you cant hold your trans in a gear that gives you redline you will never get accurate hp numbers.

FLM1

Horsepower is the amount of work done in a given amount of time. Example, moving a given amount of weight 1/4 mile in a given amount of time.

biohazard

i can use 4th gear just need a reprogrammer to come out

NJHK

1/4 mile times have to deal with horsepower, torque, your powerband, the type of tires you have, the size tires you have, the size rims you have, your driving skill, your cars condition etc etc.

There are way too many variables to say "you run XX.X times so you have X amount of horsepower". There have been people with SRT-4s who can't drive worth a damn and miss gears and run high 15s in the 1/4 mile...does that mean they have less horsepower, no. It means they can't drive and messed up their 1/4 mile times but their power still remains the same.

1/4 mile times is a way of seeing how fast you are, not how much power you have.

3fo893013L

yah, your dyno place sucks. they only dynoed half the cars hp rating. I have a 2.2 Cobalt Sedan LT and my rev limiter is like 6k rpm or something to that nature. my SS I can wind it up to almost 6500RPM before boing!

When I dynoed my sedan it was 134hp to the wheels stock down to the air filter(btw it's an auto). My SS is getting about 240whp with intake and exhaust.

biohazard

how did you dyno the auto? lock it into second or something? or do u have the LS witrh the higher limiter.... the place dosent "suck" they were very good we just couldnt bypass the limiter without a reprogrammer..... we just didint think to try locking it in second... should i try that?

and im not talking about rev limiter thats 4K on the cobalts.... i ment the top speed limiter.... the fuel cutoff

NJHK

I knew you were talking about speed limiter.

On my shifter, I can put it to "3" and leave it there and it won't go into 4th gear (aka overdrive).

campo165

Just a thought, I believe torque=horsepower ALWAYS at...5252 rpms? At that moment, the torque should equal the horsepower (according to the formula)

FLM1

No, HP=RPM x Torque/5252, but you have to have full rpm.

FLM1

You could try to hold in second gear, and with your foot still in it, shift trans to (D). it should only shift to third gear, and hopefully it'll keep it there close to redline. But I think that if you let your foot out of it at all, the trans will shift into fourth. The dyno guys might not like it to shift that hard though.

Asphalt Assault

Cause not everyone reads the whole post and some have an SS and dont understand the problem yet.

NJHK

I think it has more to do with people not looking at things logically.

NJHK

dstinsman56

i've seen alot of dynos and if it didnt downshift to third gear on the dyno they were going to fast when they started. If you were to race at the track it wouldnt go straight into 4th from second it would go to third and hit redline before shifting. they need to be going slow enough for it to down shift to third. the only prob with that is your dyno will only be from like 3 or 4k up to redline you will have nothing before. but it will show you peak hp which is what your after.

maxpit

Nice torque curve. especially for 2.2
Only reason you stopped making Hp is because u hit the rev limiter. Dont worry your car is fine.

2K5SS/SC?

First off from reading this there are two big things I noticed.
1. Your Cobalt does not have a 4K rev limiter, it's more like 6500.
2. Bump shift your tranny up from 1-2-3, when you get the go hammer it until it's just before touching the rev limiter. Dyno the 4speed auto in 3, and I guarantee your numbers will be higher.
3. Don't forget to put on the e-brake if you have traction control while on the dyno, that'll mess up your numbers as well.

forcedgminduction

this is just a question. does the base auto have an overdrive off switch? i know some econo cars do because in fourth they wont make enough power to hual a full load at highway speeds. and off topic, with the aftermarket parts you have, i would recomend going to 2 1/4 pipe. it doeant help your current situation, but it could gain you some numbers

NJHK

Not being rude but this has been said multiple times and he's replied to each of those comments you've made.

Chevypowered

Whats the top speed of 3rd gear?? If thats over 105 do a 2nd gear pull, the numbers will be a little higher than they should but you'll get a good idea of what your car is doing. If third gear doesn't go to 105 then you should be able to do a 3rd gear pull without hitting the limiter, they dyno place should know what to do.

jokieman

Can't you just take the ratio for second gear and divide it down to a 1:1 ratio to get true numbers?