bo0oost

I'm going to dyno my car tomorrow, and had a few questions.

1) What is the best gear to dyno in for our cars? I have 3.42s. M6.

2) What is the optimum a/f ratio?

Some info about my car:

2000 Z28 M6, 6.0L heads CNC stage 2, 226/232 112LSA Comp Cam, 7200 redline, 98 injectors, stock fuel pump, LS6 Intake manifold, FTRA, ASP Underdrive pulley, stock throttle body, hooker headers, no cats, 3" hooker ypipe, mufflex 4" catback, SLP whisper lid, K&N, z06 maf, 10.8:1 CR

I'm going to be running on a dynojet. Do these typically read higher or lower, or correct? I know the mustang dyno'd read lower usually.

I have a MAFT, and Autotap. I heard the AF ratio the dynojet reads is typically 1 pont lower than at the motor, since the reader is in the tailpipe. What o2s should I be looking at, and what A/F will this correspond to?

What timing should I be getting?

This will be on CA 91 octane.

Any tips? Thanks!

11 Bravo

iTrader: (3)

7200 redline? Stock bottom end ? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

bo0oost

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 11 Bravo:
<strong>7200 redline? Stock bottom end ? <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yeah.

Anyway, can you help with my questions? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> I'm going to dyno in the morning! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

trackbird

iTrader: (4)

I ran mine in 3rd 4th and 5th and 3rd and 5th lost about 15 hp and 18 ft lbs compared to 4th (due to driveline drag and lack of mechanical advantage 3 and 5 respectivly). I did have them run mine from 2000 rpm in 3rd to the 158.1 mph shut off (where it was making 285 hp @ 158.1 mph, stock with 4,000 miles and a lid). For the best #'s, run it in 4th gear, but it is interesting to see the differences (I can't seem to find my dyno sheed with all 3 graphs overlayed). Just what I learned Good luck.

PS 158 mph sounds evil on a dyno.....

bo0oost

Trackbird - Interesting, thanks.

I'll dyno tomorrow in 4th gear.

I just went to tune my car, and noticied my ATAP was reading 50mV at WOT. I turned the MAFT up from -4 to +6, and got 880mV at wot. Feels much better too. but at 50mv, I was getting 28 deg timing, no knock... weird.

NEVR2ND

iTrader: (10)

Dyno in 4th, don't waist your time and money dynoing in 3rd, or 5th. Inflate the rear tires to 32+ PSI, the higher the better but don't exceed max recomanded pressure. A/F ratio 12.8 to 1. Keep an eye on the timing being retarded retard. I think you should pull 420+ RWHP.
Goodluck. Keep us posted.
<img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" />

<small>[ November 23, 2002, 12:56 AM: Message edited by: NEVR2ND ]</small>

bo0oost

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by NEVR2ND:
<strong>Dyno in 4th, don't waist your time and money dynoing in 3rd, or 5th. Inflate the rear tires to 32+ PSI, the higher the better but don't exceed max recomanded pressure. A/F ratio 12.8 to 1. Keep an eye on the timing being retarded retard. I think you should pull 420+ RWHP.
Goodluck. Keep us posted.
<img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Great tips!! Thank you!

4th gear it is.

I'll check my max pressure for the tires, and inflate to that.

So when you say AF 12.8:1 that's at the tailpipe where they check, right? Just want to make sure you're not talking wideband, because I don't have one.

I don't have to worry about my timing, right? As long as AF is fine, I'm set?

Very excited!! Thanks!!

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

trackbird

iTrader: (4)

Good luck....let us know what it makes.

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

niphilli

It would not be a bad idea to drop the buck and go to a shop with LS1 Edit considering all of your modifications. With LS1 edit you could check/adjust timing, adjust A/F, remove KR, turn off cat overtemp, tune in your injectors, and get rid of your EGR (assuming you had a pre-01). My $.02. You definately want to dyno in 4th and shoot for 12.8-13 on your A/F. 12.8 being a good conservative street tune.

-Nick

<small>[ November 23, 2002, 08:30 AM: Message edited by: niphilli ]</small>

trackbird

iTrader: (4)

I wanted to see the difference in drive train loss in 3rd 4th and 5th. I am an autocrosser and road racer and will be running open track events and I hope to make the Nevada silver state challenge soon. I was concerned about top end hp (and how much I'd need to overcome driveline losses), that's why I did a 3 gear pull. But it proved that driveline losses are not as bad as I expected and that 4th gives the best #'s.....

NEVR2ND

iTrader: (10)

Dyno one after the other.
3rd--362 RWHP, 349 RWTQ
4th--380 RWHP, 372 RWTQ
18 HP-----23 TQ

bo0oost

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by trackbird:
<strong>Good luck....let us know what it makes.

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Damn dyno was closed for some reason <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> oh well, next time