Please help!! Missing over 50rwhp after G5X3/LSX intake install! Dyno graph inside.
03-08-2004, 01:55 PM
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Originally Posted by Ragtop 99
If the A/F is perfect, why does A/F go off the map on the lean side at 5800 rpm on 1 pull and by 6200 on the other pull? I notice your original baseline graph from 2002 shows a much cleaner looking A/F. Maybe the A/F readings are in error?
Originally Posted by verbs
Ignore the A/F spike at 6000+rpms, that was the o2 sniffer falling out of the exhaust.
03-08-2004, 09:55 PM
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Well, had to postpone dyno/troubleshooting till tomorrow morning so I'll update tomorrow. However, this afternoon from a 10-90mph roll I put about 5 cars on a heads/cam M6 Vette putting down 410rwhp. Maybe it was the spark plug wires?
03-08-2004, 10:19 PM
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Originally Posted by verbs
Well, had to postpone dyno/troubleshooting till tomorrow morning so I'll update tomorrow. However, this afternoon from a 10-90mph roll I put about 5 cars on a heads/cam M6 Vette putting down 410rwhp. Maybe it was the spark plug wires?
03-08-2004, 11:37 PM
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Originally Posted by verbs
Well, had to postpone dyno/troubleshooting till tomorrow morning so I'll update tomorrow. However, this afternoon from a 10-90mph roll I put about 5 cars on a heads/cam M6 Vette putting down 410rwhp. Maybe it was the spark plug wires?
03-09-2004, 09:14 AM
#70
Originally Posted by verbs
Well, had to postpone dyno/troubleshooting till tomorrow morning so I'll update tomorrow. However, this afternoon from a 10-90mph roll I put about 5 cars on a heads/cam M6 Vette putting down 410rwhp. Maybe it was the spark plug wires?
03-09-2004, 11:29 AM
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Originally Posted by 66ImpalaLT1
Who was that?
Had an MMS heads/cam package, he said his cam was a "318" but I think he meant 218 duration.
03-09-2004, 11:35 AM
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I just checked the log from my dyno run and looked at the g/second readings from the MAF.
Two things caught my eye. The first, is that overall the g/second being read by the MAF steadily increases, but it dropped a few times along the way. For example (not the actual #'s) it worked kind of like this.....
RPM Grams/Second
2500 100
2700 110
2900 120
3100 130
3300 110
3500 135
3700 145
3900 155
4100 135
4300 155
4500 170
I dunno, but to me that seemed odd that it kept dropping like 20-25cfm at times along the way, although it climbed steadily to about 6000rpms.
Then at 6000 rpms, the g/sec peaked at a shade over 300, but then started to fall steadily all the way to the redline, so at say 6200rpms it was pulling 290 g/sec, 6400 280 g/sec, etc.
My understanding was that my g/second readings should have increased all the way until I made peak power.
Two things caught my eye. The first, is that overall the g/second being read by the MAF steadily increases, but it dropped a few times along the way. For example (not the actual #'s) it worked kind of like this.....
RPM Grams/Second
2500 100
2700 110
2900 120
3100 130
3300 110
3500 135
3700 145
3900 155
4100 135
4300 155
4500 170
I dunno, but to me that seemed odd that it kept dropping like 20-25cfm at times along the way, although it climbed steadily to about 6000rpms.
Then at 6000 rpms, the g/sec peaked at a shade over 300, but then started to fall steadily all the way to the redline, so at say 6200rpms it was pulling 290 g/sec, 6400 280 g/sec, etc.
My understanding was that my g/second readings should have increased all the way until I made peak power.
03-09-2004, 12:24 PM
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**Update** Well just strapped her onto the dyno with the only changes being the plug wire swap, and it put down 430rwhp/381rwtq. The graph is no longer shaky like it was before. Making progress, but still got a ways to go. Both of my o2 sensors seem to not be switching as much as they should, and my car threw a MAF sensor code recently, so I'm going to change out all of those and redyno.
Surprisingly, there are absolutely no signs of vavle float with the YT rockers on. The car does peak kind of early though, at around 6200rpms. HP stays above 420rwhp until about 6900rpms. I'll post the 430rwhp graph tonite.
Surprisingly, there are absolutely no signs of vavle float with the YT rockers on. The car does peak kind of early though, at around 6200rpms. HP stays above 420rwhp until about 6900rpms. I'll post the 430rwhp graph tonite.
03-09-2004, 12:29 PM
#75
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I would swap the MAF or clean it, and I'd swap the 02 sensors. Bad or dirty MAF can eat up 20rwhp no problem.
I would stop crying wolf about the Y/T rockers, they are JUST plain ol' rockers. The reality is that a lot of springs don't work past 6600 for most cars, not just ours. Read the MM&FF article by David Vizard about his testing of of springs recently.
I would stop crying wolf about the Y/T rockers, they are JUST plain ol' rockers. The reality is that a lot of springs don't work past 6600 for most cars, not just ours. Read the MM&FF article by David Vizard about his testing of of springs recently.
03-09-2004, 02:55 PM
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My car has trapped the same before and after the addition of Yella Terras and I shift at 6800-7000 rpm.
Not so sure I'd be placing the blame on them yet
Not so sure I'd be placing the blame on them yet
03-09-2004, 03:38 PM
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Originally Posted by LiquidSnake
Did you do any compression test?you should read at least 150+psi on all cylinders.It'll show you the valve leaks etc.
I do however have 4-8% leakdown on most cylinders.
Next step is going to be putting stock rockers, no shims and 7.35 pushrods all around, instead of just the exhaust side.
Also going to let the car dyno in speed density mode by unplugging the MAF to see if the plug itself is bad.
The MAF sensor itself is fine. I swapped that and there weren't any problems.
03-09-2004, 03:41 PM
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Originally Posted by verbs
We did that a while back and that's how we determined the heads needed new valves. I have all new valves/seals, so that shouldn't be the problem.
I do however have 4-8% leakdown on most cylinders.
Next step is going to be putting stock rockers, no shims and 7.35 pushrods all around, instead of just the exhaust side.
Also going to let the car dyno in speed density mode by unplugging the MAF to see if the plug itself is bad.
I do however have 4-8% leakdown on most cylinders.
Next step is going to be putting stock rockers, no shims and 7.35 pushrods all around, instead of just the exhaust side.
Also going to let the car dyno in speed density mode by unplugging the MAF to see if the plug itself is bad.
Hey I tried to PM you, but your box was full earlier. It's kinda off subject, but are you still using stock injectors? If not, what are you using.
Thanks