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View Full Version : First N/A shakedown passes on new combo



Nostang 96z
12-03-2016, 06:09 PM
Posted on ls1tech as well*.
Finally made it to the track today with the new combo to make some passes. The weather was low 50's and pretty nice out except for the occasional gusty wind. Drove 20 miles to the track, retorque the wheels, did a look over and safety check and ran. The QA1's were set to 4 on the front and 8 on the back. I had 47 psi in the front tires and 18 in the rears (MT drag radial 27.8"). I was datalogging to try and dial in the tune at the track and did not use the trans brake.

1st pass (idle launch)
1.569
4.489
6.971
99.119.121
10.955
122.71

2nd pass (had my tuner on the phone and he made the corrections to the VE table to get the wideband corrections under 5%---the car was pulling fuel to keep it at a target A/F ratio of 13.1)
1.573
4.497
6.975
98.38
9.150
11.008
121.06

3rd pass ( I changed the A/F table to target 12.7 instead of 13.1 at WOT--back to where I was on the first pass)
1.563
4.488
6.960
99.18
9.107
10.940
122.85

4th pass(kept the tune the same but foot braked it to 2850rpms--no real change)
1.582
4.505
6.979
99.19
9.123
10.956
122.74

5th pass(changed the target A/F table to 12.7 from 12.6 at WOT---picked up a some hp!)
1.571
4.488
6.948
100.2
9.069
10.873
124.68

6th pass (changed the A/F table from 12.6 to 12.5 at WOT---picked up some more mph)
1.584
4.513
6.974
100.23
9.095
10.899
124.74

7th pass (changed the A/F table from 12.5 to 12.4 at WOT---ran into some issues)

Went to shift from 1st to second and the car shifted then went right to 7600rpms (rev limiter). I let off and coasted the rest of the way down. I am not sure if it is a shifter cable or a trans issue but will have to trouble shoot it to see. The car drove the 20+ miles home OK and shifted fine so I need to investigate.

It was the first time since July 06 that I had this car to the track so I had a blast. I think the car has a 10.6-10.7@126mph as it sits with some more tuning. I still need to clean up the part throttle and acceleration enrichment tables but wanted to get the WOT tables down. I really wanted to see how it would react with the 12.4 A/F ratio. I felt like it was leaning out in the middle of second and third so I want to get this smoothed out and the tune spot on before any nitrous is added. The car still has 3.7 gears which kills my ET and mph. The converter was flashing to 4600 on the logs from idle so it should really pick up on the bottle as well as on the trans brake. The car weighs in at 3600 with driver and fuel. The old lt1 was putting in some decent times and was very consistent. The suspension on the car really works and the car is so easy to drive down the track.

Matt __________________

383z
12-04-2016, 04:15 AM
Amazing times!
Im would be satisfied with those numbers.
What are your mods and can you give some details? Pics?

Nostang 96z
12-04-2016, 02:33 PM
Thanks for the compliments.

The combo is a 96 Camaro z28 @3600 lb raceweight, 383lt1 12.15-1 comp., ported AFR 220 heads, T&D 1.6 shaft mount rockers, accel single plane ported pro ram, 4bbl throttle body, solid roller cam 259 267 @.050 .65x lift 108lsa, 8" FTI converter, CPT TH400 with t-bake, ford 9" 3.7 gears, 28" ET street drag radial, 1.875 headers with 3.5" y-pipe, mufflex 4" exhaust, GZ motorsports vacuum pump, tubular a-arms/k-member, hal qa1 shocks, madman torque arm, full cage, FAST XFI, and some other custom fab stuff. The combo is setup for the nitrous and that is the reason for the 3.7 gearing. The combo really struggles with the 3.70's and would actually prefer a 4.3-4.56 gear in the rear which would net me ~.3-.5 tenths with no other changes.

I still have some tuning to do with the combo to dial it in N/A but ran into some trans cable issues and was out of time yesterday. Every time I added fuel to the tune the car picked up mph/ET even hot lapping it towards the end of the day (10 minutes between runs on the last 3). If I am able to get another day at the track I will get the fuel dialed in and then play with the timing. One small change in the fueling netted 2mph and 1 tenth. I am still running rich down load and need to lean out the enrichment tables which should help the 60 ft a little. I also need to really use the t-brake off the launch which should hopefully get the 60 ft into the 1.4x range. I am flashing to below peak torque by ~200rpms so it feels sluggish out of the hole.

Once I am done tuning the combo N/A I will start spraying the combo. I have a Monte Smith flowed nitrous plate on the car already with a separate fuel cell and fuel pump for the nitrous. I will start with the 100-150 jets and work my way up from there. The XFI has progressive control but I think the suspension and chassis will handle a 150 hit right off the line. The kit is flowed to 275 but I will most likely only spray the combo to get it into the low 9's. I built the combo to run 1 second faster than my old 355.

The old 355lt1 ran 11.44@117.8mph with a 1.579 60ft with 4.11's, nitrous converter, and a 26" tall tire. I changed the gears to 3.70's and a 28" tall tire and ran 11.9@114mph with a 1.78 60ft N/A. However, on the bottle the car went 10.35@129 w/ 1.437 60 ft and 10.2@134mph with a 1.58 60ft as it was pig rich. I never really dialed in the old combo but was happy with the performance back in 2003...lol.


There are pics of the car somewhere on this site that I uploaded a while ago. Not sure how to find them.

96LT1355Z28
12-04-2016, 07:20 PM
Nice times, our setups are very similar! Sound like your moving in the right direction! What do you thing of the GZ vacuum pump, that's on my list for this winter.

Nostang 96z
12-04-2016, 09:11 PM
Thanks, it is getting there. Need to get it fine tuned and launch on the t-brake and I think it has a 10.6 in it with the current gearing/tire. I know it would pick up a a lot with a set of 4.33's but that is the tradeoff for the spray.

The GX motorsports kit is great. A nice bolt on install. I am pulling about 7-10" vacuum depending on the weather at WOT and 6k rpms.

BTW, what gears/tires are you running in your setup?

TravisMcGill2000
12-04-2016, 11:07 PM
Great times for 1st time back out. Glad to see it running again. Can't wait for some passes on the bottle

96LT1355Z28
12-05-2016, 12:02 PM
Thanks, it is getting there. Need to get it fine tuned and launch on the t-brake and I think it has a 10.6 in it with the current gearing/tire. I know it would pick up a a lot with a set of 4.33's but that is the tradeoff for the spray.

The GX motorsports kit is great. A nice bolt on install. I am pulling about 7-10" vacuum depending on the weather at WOT and 6k rpms.

BTW, what gears/tires are you running in your setup?

T56 with 4.30 gear and a 28x10.5 ET Drag (3055S) on a 10' wheel. Good to hear about the GZ kit, many of the racers near me have a Moroso pump and sourced everything else individually.

Nostang 96z
12-05-2016, 12:23 PM
The GZ pump is a good pump for the street as it is a different design than the Moroso. The kit comes with everything needed for the install and their support is great.

Nostang 96z
12-08-2016, 12:11 PM
I figured out the missing/surging issue. #5 spark plug boot was melted completely to the plug. Figure it was like this all summer and I never noticed the missing as I did not floor the car much. That should net me some decent gains once I fix that issue.

agenthol302
12-08-2016, 02:28 PM
Awesome job man!, sounds like it will be a deadly consistent bracket car if you go that way......wish we still had tracks open

Nostang 96z
12-09-2016, 01:04 PM
Thanks, Our tracks will be closing next Saturday but they are only open if the weather is decent. The northeast weather is pretty crappy. I am sure the Minnesota weather is similar.

The car has always been pretty consistent even with the old combo. I have the chassis dialed in pretty good, just need to add more power.

Badhawk
01-04-2017, 07:41 PM
Nice job sounds like you got it figured out.