I know it probably sounds dumb, but should I do the dyno pull in 3rd or 4th gear? I'm not sure which would make it "easier" to tune the car.

Any other advice you can give me would be great. I'm tuning for 20psi(for the track), and also 15psi for daily driving.

TIA! Here's crossing my fingers to not blowing it the eff up :puke


thanks guys!

You'll want to do it in 4th gear. It has a closer to 1:1 gear ratio.

Originally posted by Avenger
You'll want to do it in 4th gear. It has a closer to 1:1 gear ratio.

+1. I remember you. Posted pics of that beautiful engine bay. Keep us updated on the runs when you are finish. Brag a little if you may.

Last itme i had mine done it was in 3rd gear.

Terry

Originally posted by Avenger
You'll want to do it in 4th gear. It has a closer to 1:1 gear ratio.

Agreed. Thats what we've always used.

Originally posted by Avenger
You'll want to do it in 4th gear. It has a closer to 1:1 gear ratio.

off topic but i was wondering if you have any 1/4 times, what kind of dyno was your 396whp put down on, since it is close to mine if it was on a mustang dyno i would like to see some times.

Personally I like 3rd gear pulls but my talon never got to a dyno. heh :rolleyes

EDIT: Try both and see what the difference is :shrug

I was always under the impression that 3rd gear was the way to go, but then again I've never been on a dyno so I'm just talking out my ass here.

thanks for the responses guys! I had to reschedule for next saturday because some guy had a group of ten cars that needed the dyno today and I guess 10 dyno $$ is better than 1. Oh well, they are giving me my 1st three pulls free for the inconvenience! I'll post the results up next saturday. Merry Christmas.

Devin, our 420a's should be dyno'ed in 3rd gear. If you have any questions you can call Aarron over at Victor Research in East Hartford, Ct. 860-282-RACE. He's the owner and does the dyno work over there. They are a mitsubishi "speed shop"

MB

Originally posted by bullettdsm
Devin, our 420a's should be dyno'ed in 3rd gear.

I'd like to see how your performs on the dyno in 3rd vs 4th gear. Next time you're out there, try it and see if there's any difference.

In RWD cars, higher rear-end ratios (>=4.10 vs <=3.55) will show higher torque, but less HP. I'm curious if it's similar in the a 3rd vs 4th gear pull.

Originally posted by cougar694u

Originally posted by bullettdsm Devin, our 420a's should be dyno'ed in 3rd gear.

I'd like to see how your performs on the dyno in 3rd vs 4th gear. Next time you're out there, try it and see if there's any difference. In RWD cars, higher rear-end ratios (>=4.10 vs <=3.55) will show higher torque, but less HP. I'm curious if it's similar in the a 3rd vs 4th gear pull.

Luke,
Funny you should say that, lol. I'm such a curious guy that I DID do that on my first set of dyno runs with the NA. Aaron told me not to but hell, he was charging me; and it was close to 10% lower (approx in torque and whp).

He said "See I told you so." He's a smart ass.

You know, next time I talk to him, I'll ask if he still has the run on file. IDK if he carries them all, but he does save some.

MB

Interesting. I did the dyno pull on my bike in 3rd gear, but I'm geared quite a bit. Someone recommended I try it again in 4th, but I didn't have time. I'm hoping to get a full tune soon, so I'll try a 3rd vs 4th pull on the bike and see if it does the same as what you found.

The gear ratio for 4th gear is 1.03 and 3rd is 1.36 (or something like that). Refer to the factor service manual or the main site for the exacts specs.

In 4th gear your motor and the output shaft are spinning at almost the same speed. In 3rd the motor is going faster than the tires.

Don't know the gearing in a 4g. Their 3rd may be closer to a 1:1 gear ratio than ours in 3rd gear. But for the 420a with a stock 3.94 geared trans you should be dyno'ing in 4th gear.

My .02 cents. But dyno'ing isn't an exact science anyway.

Originally posted by Avenger
But dyno'ing isn't an exact science anyway.

It's strictly a tuning mechanism to me.

Yep. Mainly for tuning and for getting a rough idea of how mods improve the car. The numbers are good for a sig too. :)

So, does any of that help you Devin, lol? I'm guessing you'll have to discuss that with the particular tuner.

MB

And I concur 100%, it is a tuning device used for comparison of changes that you make.

Originally posted by bullettdsm
So, does any of that help you Devin, lol? I'm guessing you'll have to discuss that with the particular tuner. MB And I concur 100%, it is a tuning device used for comparison of changes that you make.

lol. Yeah, it looks like it. Thanks for all the input guys. I have to put the dyno off for a minute. It seems that I have "sprung a leak" around the driver's side rear of my engine. (dun dun duuun)

I'm being as optomistic as possible by hoping it's the piece of shit brass t-fitting where my turbo feed line and oil pressure gauge are run from. It's only leaking oil at high to full boost(1.5 bar). So at least I'm not having to add oil every day. I'm just not boosting it right now. I'm taking it to the dealer tomorrow so I can get it on a lift so I can clean it up and see where it's coming from exactly. I'm hoping the t-fitting is loose or cracked. If it's the HG then I will have to put off the SB clutch I was gonna buy this week. I don't feel like changing a HG in bitter ass cold weather, but oh well, if I have to I have to right? lol.

wish me luck

Whats it cost to dyno a car say 10 runs

It depends on a lot. For my last 4 runs I did it cost me $70 and change. The first three were like $60 then I got charged for the last one (he did me no favors. Geez, I'm doing all the tuning and it was less than an hour but he still hit me up....anyway). Some places will do it by the hour, some places will give you like the first 3 for one fee then charge you for time or pulls. If you are tuning it, will be one price, if you are having them tune it will be different.

Lots of different variables. If I was to do 10 pulls, with them tuning, it would probably cost me (at this dyno) $150 for the tuner, $100 for the first 3 pulls then another......Wait, let me just shoot you an addy and you can take a look at their rates. just click on the dyno links.

http://www.victorresearch.com/

That'll give you an idea.

MB