No top end

[3.8vsix]

I went to the Bristol Bash this weekend and I am a little disappointed. The car just will not pull passed the 1/8th. I have new vavle springs, and even got some 27x10.50 hoosiers. My best mph was 113.96, this was with 26psi boost and 40psi fuel pressure (with line off). The o2's mv's was in the 790 range. The problem is that it was surging on that pass. I then turned the fuel pressure up to 42psi an it quit surging, but my o2 volts was in the 820's. It was still in the 113mph range. Do you guys think it is time for a chip reprograming or plugs or should I have turned up the fuel pressure more? I think the car should have run in the 116 to 118 mph range with that much boost. BTW, the mph in the 1/8th was 93 mph. The weather was in the high 50's, the car should have run much better than it did. Thanks for any help

 

[3.8vsix]

ttt

 

[azgn]

what is your rpm thru the traps?

94 in the 1/8 would indicate 116 plus in the 1/4 if the car is running well.....(most good running TR's will add 22-26 mph in the last 1/8....)

any knock?

don't live and die by 02 volts...that is a very unreliable tuning indicator (I ASSume you were running race gas....the 02 could be toast...)

next time, add some more fuel pressure and see what happens

get an egt if you are going to run that kind of boost

consider another chip ie MaxEffort

 

[3.8vsix]

Thanks for the reply. The rpms was 5300 in drive when I crossed the traps. I put in a new O2 sensor that morning and I know that it was good. I had no knock and was running 112 octane. How hard is it to get the Maxeffort dial in?

 

[azgn]

I think you have some unwarranted "slippage" on the top end.....I am not that familiar with the AC non locker, but at 122 with my converter locked, I was seeing 5100 or so (27" tire)

if you are pulling 5300 rpm in 3rd, doesn't seem like the motor is laying down....more like the converter/trans is slippping more than it should.....1st & 2nd gear look ok, but maybe something in the 3rd gear clutches?

maybe someone running that converter can give you some mph vs rpm in 3rd

are you running a 26" tire?

the MaxEffort is very easy to dial in....usually work fine out of the box....and no more 02's to buy

 

[3.8vsix]

yes I am running the 27 inch tires. Can any one give me there rpms with the A/C non lock? Which of the max effort chips should I get the 8 or 16 pos? Thanks.

 

[azgn]

16 position only!

 

[blackbuick87]

Last time I talked to Steve he was planning on phasing out the 8 pos ones.