What could be wrong with tuning to have TQ so low???
02-26-2005, 10:21 PM
#21
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What are you running timing wise at 2K 3K 4k 5K 6K?
What does the AFR look like at 2K 3K 4K 5K 6K?
With a larger cam you'll have to run a little more timing down low to make up for the loss of cylinder pressure.
What does the AFR look like at 2K 3K 4K 5K 6K?
With a larger cam you'll have to run a little more timing down low to make up for the loss of cylinder pressure.
02-26-2005, 11:25 PM
#22
His timing is pretty steady 27-28 all the way through the run. Michael, try plugging in your maf but set the fail frequency to 0 hz or something. I think that way you can still run in SD, but you can also see how much massflow you're getting. A rough estimation is 1 lb/min = 10 rwhp, so if you're flowing the air you know the problem is probably somewhere else.
BTW I only commented on your SD tune cause I saw lots of -8 and -9 in the histogram so I wasn't sure if you were doing SD or just forgot to plug your maf in. It really doesn't matter for this thread though.
BTW I only commented on your SD tune cause I saw lots of -8 and -9 in the histogram so I wasn't sure if you were doing SD or just forgot to plug your maf in. It really doesn't matter for this thread though.
02-27-2005, 12:42 AM
#23
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P Mack, how do I set the fail frequency to 0 in HP TUners? I will do compression check AND a log with MAF plugged in fail @ 0 tomorrow ok?
AFR is 12.5 to 12.6 from 2k up to 6800 where I'm shifting.
Also the -8 and whatever only matters that it's -, and not + right? I thought - was good as long as was under -10?
AFR is 12.5 to 12.6 from 2k up to 6800 where I'm shifting.
Also the -8 and whatever only matters that it's -, and not + right? I thought - was good as long as was under -10?
02-27-2005, 01:10 AM
#24
Originally Posted by foff667
i would assume its a velocity issue with the heads and the split cam...i put down 373/339 with my 231/237 with patriot heads...probably a similar type issue as yours...that was with a cartek tune in my car as well...just better have a big converter 
This sounds way too much like me
With the 231/237 cam, TSP race style LS6 heads (11:1 compression), TCI streetfighter 3200 stall converter, and all the other mods I did, I was expecting to be in the low 400's at least, on HP and TQ. Though I found out way too late in the season that false knock (and me messing with the H.O. timing to rid the knock)was absolutely killing my timing (~20deg at WOT), I had the car dyno'd on a Mustang AND a Dynojet. AFR was a little rich, but only got 351rwhp 305rwtq on the Mustang, and 347rwhp and 312rwtq on the Dynojet.
For this amount of money and effort, 305rwtq absolutely
I really hope you learn what's up with your car, because i'm hoping to learn from it where I lost all my torque too. Your other thread mentioned that too much material removed from the heads could be the culprit. I hope they're wrong, because if that's my problem, I don't have another $2000+ for another set.
02-27-2005, 01:26 AM
#25
Originally Posted by Michael Ozorowsky
P Mack, how do I set the fail frequency to 0 in HP TUners? I will do compression check AND a log with MAF plugged in fail @ 0 tomorrow ok?
AFR is 12.5 to 12.6 from 2k up to 6800 where I'm shifting.
Also the -8 and whatever only matters that it's -, and not + right? I thought - was good as long as was under -10?
AFR is 12.5 to 12.6 from 2k up to 6800 where I'm shifting.
Also the -8 and whatever only matters that it's -, and not + right? I thought - was good as long as was under -10?
02-27-2005, 04:49 PM
#28
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Boy Michael, that tq curve looks bad. Nice & flat, but missing the spike for the max tq/power area. And your hp doesn't take off at 4500 rpm like I'd expect with your setup either. 3 thoughts....
No KR, right? Are you SURE?! You ran the chart while dynoing.....
Did they over torque you rocker arms? That will rob power, and some people do that to quiet down LS1s with BIG cams.
Do a compression check. Cams with 600 lift have been known to make the valves kiss the pistons on some heads. Tho it's usually only a problem with milled heads w/thin head gaskets. But that will kill your power because all cylinders are leaking slightly.
And I'd replace the GMAF electronics with the stock one (but keep the ported ends on the car). Won't address this specific issue, but it's just a good idea IMO.
On a side note, 2 guys out here got nice power with 231/237 cams. One has stock heads (390hp/370tq thru a 12 bolt) & one has big heads (425hp/410tq thru a 9"). So this style cam CAN make decent power.
No KR, right? Are you SURE?! You ran the chart while dynoing.....
Did they over torque you rocker arms? That will rob power, and some people do that to quiet down LS1s with BIG cams.
Do a compression check. Cams with 600 lift have been known to make the valves kiss the pistons on some heads. Tho it's usually only a problem with milled heads w/thin head gaskets. But that will kill your power because all cylinders are leaking slightly.
And I'd replace the GMAF electronics with the stock one (but keep the ported ends on the car). Won't address this specific issue, but it's just a good idea IMO.
On a side note, 2 guys out here got nice power with 231/237 cams. One has stock heads (390hp/370tq thru a 12 bolt) & one has big heads (425hp/410tq thru a 9"). So this style cam CAN make decent power.
02-27-2005, 06:28 PM
#29
Originally Posted by WAHUSKER
Boy Michael, that tq curve looks bad. Nice & flat, but missing the spike for the max tq/power area. And your hp doesn't take off at 4500 rpm like I'd expect with your setup either. 3 thoughts....
No KR, right? Are you SURE?! You ran the chart while dynoing.....
Did they over torque you rocker arms? That will rob power, and some people do that to quiet down LS1s with BIG cams.
Do a compression check. Cams with 600 lift have been known to make the valves kiss the pistons on some heads. Tho it's usually only a problem with milled heads w/thin head gaskets. But that will kill your power because all cylinders are leaking slightly.
And I'd replace the GMAF electronics with the stock one (but keep the ported ends on the car). Won't address this specific issue, but it's just a good idea IMO.
On a side note, 2 guys out here got nice power with 231/237 cams. One has stock heads (390hp/370tq thru a 12 bolt) & one has big heads (425hp/410tq thru a 9"). So this style cam CAN make decent power.
No KR, right? Are you SURE?! You ran the chart while dynoing.....
Did they over torque you rocker arms? That will rob power, and some people do that to quiet down LS1s with BIG cams.
Do a compression check. Cams with 600 lift have been known to make the valves kiss the pistons on some heads. Tho it's usually only a problem with milled heads w/thin head gaskets. But that will kill your power because all cylinders are leaking slightly.
And I'd replace the GMAF electronics with the stock one (but keep the ported ends on the car). Won't address this specific issue, but it's just a good idea IMO.
On a side note, 2 guys out here got nice power with 231/237 cams. One has stock heads (390hp/370tq thru a 12 bolt) & one has big heads (425hp/410tq thru a 9"). So this style cam CAN make decent power.
I did my own heads/cam swap, and used the Felpro gaskets listed on LS1speed's website. The rocker arms were torqued to ~22lb/ft +/- 1lb/ft, and loktited.
I know I had KR, hopefully, with HP Tuners, I'll have tuned it out come spring.
Haven't done a leakdown test yet, Maybe I'll have to research that some more.
Thanks
I'll keep
hoping something else turns up.
02-28-2005, 12:49 AM
#30
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Wahusker, absolutely ZERO KR, compression check is as follows:
Drivers Side Passenger Side
1) 130 psi 1) 145 psi
2) 150 psi 2) 155 psi
3) 130 psi 3) 135 psi
4) 140 psi 4) 150 psi
Note: Goes from front of car (1) to rear of car (4).
MAF isn't a problem I'm running a custom SD Tune. Running 28* of timing across the board.
Also I did the swap myself, and torqued the rockers to like 18ft lbs with locktite. I did whatever the spec was on ls1howto.com. I'm working with Mike from Felber Racing, and gonna figure something out. Great guy btw.
Drivers Side Passenger Side
1) 130 psi 1) 145 psi
2) 150 psi 2) 155 psi
3) 130 psi 3) 135 psi
4) 140 psi 4) 150 psi
Note: Goes from front of car (1) to rear of car (4).
MAF isn't a problem I'm running a custom SD Tune. Running 28* of timing across the board.
Also I did the swap myself, and torqued the rockers to like 18ft lbs with locktite. I did whatever the spec was on ls1howto.com. I'm working with Mike from Felber Racing, and gonna figure something out. Great guy btw.
02-28-2005, 08:18 AM
#31
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Those are all within tolerance (I believe) but cyl #1 & 5 do look a tad low, as well as #6.
Cyl numbering sequence is as follows: Dr side 1,3,5,7 front to rear. Pass side 2,4,6,8 front to rear
Anyway, you say you are working this out with the guy you got the heads from, and I think most of us agree that is the most likely problem area. I was trying to find something else, anything else, that it could be before throwing in the towel & saying it.
Good luck Michael & keep us posted about what you find.
Cyl numbering sequence is as follows: Dr side 1,3,5,7 front to rear. Pass side 2,4,6,8 front to rear
Anyway, you say you are working this out with the guy you got the heads from, and I think most of us agree that is the most likely problem area. I was trying to find something else, anything else, that it could be before throwing in the towel & saying it.
Good luck Michael & keep us posted about what you find.
