My impressions tuning a 90mm combo without drilling
01-11-2005, 01:52 PM
#1
My impressions tuning a 90mm combo without drilling As a few of you know I just switched to the Fast 90mm intake and TB combo. The install was very straight forward and took about an hour after I cleaned up(ported) the FAST 90mm intake manifold and bolted the up the 90mm TB.
Tuning was the next task. Since my car had a LS6 and home ported high flow anti idle TB my tune was off. My old TB had the lip removed before the butterfly which makes tuning a nightmare. The new combo bolted right up and fired up, idles nicely. I logged the MAF GM/s and input that into the computer program. Started it back up and idles even better but had a problem with stumbling coming off a rev. We expected this with the radical cam in the car.
Next I reduced the factory IAC tables by probably 15%. The stumbling was definitely less than before. I reduced it again by 20% yeilding even better results with a slow idle down(~4 seconds) from 1600 to 900. Still alittle surging but when I mean alittle its mininal. I reduced the table again by 10% and started the car up. idles great. Surging is basically gone but still very slight surging. The adaptive learn will probably correct this. Next were going to work on the Airflow decay to get the throttle RPMs to drop and stick. As always I'll keep you guys posted.
Phil
Tuning was the next task. Since my car had a LS6 and home ported high flow anti idle TB my tune was off. My old TB had the lip removed before the butterfly which makes tuning a nightmare. The new combo bolted right up and fired up, idles nicely. I logged the MAF GM/s and input that into the computer program. Started it back up and idles even better but had a problem with stumbling coming off a rev. We expected this with the radical cam in the car.
Next I reduced the factory IAC tables by probably 15%. The stumbling was definitely less than before. I reduced it again by 20% yeilding even better results with a slow idle down(~4 seconds) from 1600 to 900. Still alittle surging but when I mean alittle its mininal. I reduced the table again by 10% and started the car up. idles great. Surging is basically gone but still very slight surging. The adaptive learn will probably correct this. Next were going to work on the Airflow decay to get the throttle RPMs to drop and stick. As always I'll keep you guys posted.
Phil
01-11-2005, 05:17 PM
#3
6600 rpm clutch dump of death Administrator
When you say IAC tables, are you talking about the Base Running airflow table, or another table?
Where do you have the IAC park position set at?
What does IAC park position vs IAT look like?
Are you using edit or HPT?
BTW, we did some testing with a 1gen NW TB, a current TPIS, and a GM 90MM TB. On a max effort 346 the GM cost 1.5 RWHP peak.
Tuning compared the the other two TBs was much better FWIW. On a stroker, I think the delta is much more apparent.
Where do you have the IAC park position set at?
What does IAC park position vs IAT look like?
Are you using edit or HPT?
BTW, we did some testing with a 1gen NW TB, a current TPIS, and a GM 90MM TB. On a max effort 346 the GM cost 1.5 RWHP peak.
Tuning compared the the other two TBs was much better FWIW. On a stroker, I think the delta is much more apparent.
01-12-2005, 10:17 AM
#4
Tried something new today:
Previous data: Logged MAF GM/s && Coolant temp on a warmup, averaged MAF GM/S @ 4 20 40 60 80 100 c
Running Airflow: Input that data into this table
IAC Park Position Reset: from 160 to 120
Startup and idles like a champ, without doing the idle relearn there is very little stumbling.
Phil
Previous data: Logged MAF GM/s && Coolant temp on a warmup, averaged MAF GM/S @ 4 20 40 60 80 100 c
Running Airflow: Input that data into this table
IAC Park Position Reset: from 160 to 120
Startup and idles like a champ, without doing the idle relearn there is very little stumbling.
Phil
01-12-2005, 10:33 AM
#5
6600 rpm clutch dump of death Administrator
Originally Posted by Phil99vette
Tried something new today:
Previous data: Logged MAF GM/s && Coolant temp on a warmup, averaged MAF GM/S @ 4 20 40 60 80 100 c
Running Airflow: Input that data into this table
IAC Park Position Reset: from 160 to 120
Startup and idles like a champ, without doing the idle relearn there is very little stumbling.
Phil
Previous data: Logged MAF GM/s && Coolant temp on a warmup, averaged MAF GM/S @ 4 20 40 60 80 100 c
Running Airflow: Input that data into this table
IAC Park Position Reset: from 160 to 120
Startup and idles like a champ, without doing the idle relearn there is very little stumbling.
Phil