Last year I installed a modular performance built lower end. I used renegade racing CNC ported heads and crower stage 2 cams. I had a Apten ported blower with a 2.7upper pulley and a 4# lower pulley. LT headers, SBTB, electric water pump, fans, powercooler, jl cai, SCT 2400 meter, SCT chip, 2400 art carr stall,NX nitrous kit set for 100shot, and ngk br7ef plugs gapped at .032. I had it dyno tuned locally and had 499rwhp and 535rwtq. On nitrous it dynoed 570/ 683. I thought this was alittle weird on the torque side. Very low in my opinion. Well I took it to the track last year and ran the truck only once before the tracks closed. Only ran 12.20@107 on motor and 11.67@115 on nitrous. Well over the winter I got a MP blower and a 8# lower pulley. I installed them and got it tuned at the same place, this time only netted me 510/600 and 588/735on N2O. Well I went by a shop that builds the TD converters last week and found out my converter (art carr) was toast! I had it replaced with the TD converter. What a difference. I was thinking this was my problem with the low numbers at the track. So I go to the track yesterday and run only on motor. The track prep was crappy, but I only could muster a 12.42@ 108.89 and a 12.27@ 109.87. Does any one have a clue what could be wrong? I would think the truck would go 11.xx@112 at the least.

Rich

 

What was your 60'? You have the power to be well into the 11's so something is not right...Looks like you did not gain much from going to the MP from the ported Eaton How much boost are you running?

 

the time slips,

The dyno graphs overlayed, before and after

Rich

 

Nobody can help me!

Rich

 

Rich -

Do you have a wideband in the truck and a way to monitor timing?
Something is not right with tune or something I would think. My truck at full weight (minus hitch and spare) and my 255lb *** in it went 90mph @ 7.68 (spinnig thru first and part of second) through the 1/8 mile.

I would guess I am making near 500/600 or close to. I am running a tune with a 11.0 A/F ratio and only 15deg of timing. Its real conservative. I still have you covered my 2-3 tenths and 3mph. You need to get everything looked at real close because you are leaving some real power on the table.

Bob

 

No wideband but do have a laptop with autotap. I would really like to know what the deal is? I have not logged with the autotap yet, I guess I will have to give it a try.

Rich