What could be wrong with tuning to have TQ so low???
02-25-2005, 11:30 PM
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What could be wrong with tuning to have TQ so low??? Only "Tuning" that is important power wise for a cam is AFR and Timing right??? Or is there something I'm dumb and not thinking of???
02-25-2005, 11:46 PM
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Michael,
I guess you're refering to this thread, right?
https://ls1tech.com/forums/generation-iii-internal-engine/281752-very-disappointed-think-s-my-fault-cam-see-here-please.html
-Mike-
I guess you're refering to this thread, right?
https://ls1tech.com/forums/generation-iii-internal-engine/281752-very-disappointed-think-s-my-fault-cam-see-here-please.html
-Mike-
02-25-2005, 11:56 PM
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Everyone Says the TQ is way low. Also, I dynoed at 342rwtq BEFORE heads/cam. Now AFTER heads/cam dynoeing like 60 more hp, but 10 LESS tq. All #'s just seem low.
Screamn, yes, that is EXACT thread I'm referring to. Going to run some logs tomorrow, just sitting at work brainstorming.
Screamn, yes, that is EXACT thread I'm referring to. Going to run some logs tomorrow, just sitting at work brainstorming.
02-26-2005, 12:03 AM
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If I have to, I will swap cam with stock and find out where the heads put me. Will run compression checks, etc. Kind of lost at this point, cuz I do all this stuff myself and have no mechanics really or anyone to turn to. But I thought since the install car wasn't as strong as I expected.
02-26-2005, 12:05 AM
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I dunno Michael. You say you lost tq, but it appears you picked up almost 20. On my car the tq started out higher than the hp, and as I added stuff the hp went up faster than the tq. And now the hp is higher than the tq. (which tracks all my friends LS1s that are close to 400rwhp) I'd try playing with fuel & timing in the max tq 4500 rpm range & see if you can move it up. (go richer & add timing)
Again, I think it's about right.
Mark
Again, I think it's about right.
Mark
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02-26-2005, 12:09 AM
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Then why is everyone telling me that for a cam of this size and heads they are making 430rwhp and like 380rwtq. But me, BEFORE heads/cam I made 337rwhp and 352rwtq NOW I'm making 389rwhp and 334rwtq. This is with stage 2 ported heads and a big cam.
02-26-2005, 12:18 AM
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Sorry, that is different than what's in your sig. That IS odd! I agree, you are about 30-40lbs of tq below where you should be. Have you asked the cam mfr for ideas?
How much timing are you running in the 4k & up range? 26-28? Or maybe it's pig-rich down low. Do you have an a/f plot? Are you running a converter by chance? I've seen them do some strange things to the tq band. Sorry, just thinking out loud here.....
How much timing are you running in the 4k & up range? 26-28? Or maybe it's pig-rich down low. Do you have an a/f plot? Are you running a converter by chance? I've seen them do some strange things to the tq band. Sorry, just thinking out loud here.....
02-26-2005, 12:33 AM
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I just looked at the other post. As they told you, with the converter & locked, your numbers could be scewed. Yanks are less prone to this than some others. (from what I hear anyway) But that still seems low. Were your previous dyno #s with the verter? And on the same Mustang Dyno? Did you get rid of the timing dip in the 4k area?
Also, Mustangs calculate differently than DynoJets do. Maybe they entered the wrong weight for your car. DynoJets pretty much just look at how fast the drum spins up. And generally give you higher #s.
What does your tq curve look like? Is it pretty flat like it was stock or does it spike early & then trail off thru the run?
Also, Mustangs calculate differently than DynoJets do. Maybe they entered the wrong weight for your car. DynoJets pretty much just look at how fast the drum spins up. And generally give you higher #s.
What does your tq curve look like? Is it pretty flat like it was stock or does it spike early & then trail off thru the run?
02-26-2005, 10:33 AM
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I assume from your charts this was this on the same dyno as before? But I couldn't find your current charts on your site. But the previous ones indicate tht tune is pretty close.
So was the stall in the car the last time? If not, then maybe the stall is doing it. Is it new? Or as a few others said, it might be the heads or heads/cam combo. Did you get the cam to match these heads (as in call them & tell them what you were doing)?
With a 67cc chamber, if the runners are hogged out for flow, & the swirl bump is gone, then you will lose a lot of bottom end. You might want all those things done for forced induction, but NA the car would suffer because there would be insufficient cylinder charge (pressure).
It could be that simple. You built the motor to be FI, and tested it NA. It's like taking the blower off a funny car. The combo needs to be complete for it to work right.....
I'll run this past a couple of the motor gods out here & see if they have an idea.
So was the stall in the car the last time? If not, then maybe the stall is doing it. Is it new? Or as a few others said, it might be the heads or heads/cam combo. Did you get the cam to match these heads (as in call them & tell them what you were doing)?
With a 67cc chamber, if the runners are hogged out for flow, & the swirl bump is gone, then you will lose a lot of bottom end. You might want all those things done for forced induction, but NA the car would suffer because there would be insufficient cylinder charge (pressure).
It could be that simple. You built the motor to be FI, and tested it NA. It's like taking the blower off a funny car. The combo needs to be complete for it to work right.....
I'll run this past a couple of the motor gods out here & see if they have an idea.
02-26-2005, 11:34 AM
#14
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 
02-26-2005, 07:19 PM
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No, that is an OLD dyno graph. ONLY thing that has changed from my last dyno to now is adding heads/cam. Do you guys think adding Nitrous to the car will solve all my problems? I am about to put a 150 wet kit on the car. Hope that'll wake it up. Here is my latest one:
02-26-2005, 07:20 PM
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Do you think a different cam would work better for me? I want as much power as possible, so if I need to swap cams I will. I'm almost debating putting stock cam back in and dynoing to see how much hp the heads alone gave me. If there is little to no difference, I need to see the head porter, right?
02-26-2005, 07:27 PM
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How are you getting away with an SD tune on an automatic? I thought there would be issues with the transmission shift firmness or something. On the log file you sent me your fuel trims are way negative so your SD tune needs more work anyway. It may be worth it to just plug the MAF in and see how much air you're flowing because that could help determine if it's a head/cam problem or a spark/compression type problem.
02-26-2005, 09:30 PM
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No, cam was not off. Also, P Mack, no problems with the SD Tune. Want me to setup MAF and send you a log? I know my Fuel Trims are still a little negative like -6 or so. Not too far off though. I didn't scale the maf. But I would have to plug in and scale it if you want I will or should I just plug in, drive and send you a log? I don't know how to properly read those logs.