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Ok fellas I have the TSP 244/248 .612/.615 114 lsa cam. My motor only dyno showed my power falling off around 6k rpm and TSP states it's power should peak around 6400 rpm. My setup is a 408, 4l80, s60, 247cc cath, fast 92/92, kooks stepped 1 3/4 to 1 7/8, TSP true duals. Made 484/454. Any ideas as to why she may be peaking early? Any suggestions to get my rpms up?
Just saw a 408 carrying power to about 6400 with the ls6 manifold. I wouldn't think the FAST 92 is your problem. Sounds like a good combo but dropping power at 6k is a bit early. Was the cam degreed on install? What about your valvetrain/springs? Can you post the graph? If you didn't say anything about rpm those peak #'s look pretty good through an auto/s60.
Mavn my first thought was the intake also but after seeing other 408s pull higher revs with the 92 and even smaller intakes like SoFla mentioned I'm thinking the limiting factor may be somewhere else. That's why I'd like to see what results others are having with the same cam.
Just looked up a little history on the motor. So you've had her running for a little over 2 years correct? You did state, in the original dyno thread, it was falling off around 6200. Does it seem to be getting worse or you're just in the same arena? One other thing I notice is the compression seems a bit low. I really can't say if that could be part of the issue or not. What do you have for your induction?
I had an issue with mine dropping off of at 6k. The graph was jagged too after 6k. I changed the old pac dual springs to btr springs and put in trend 3/8 tapered rods and she screams to 7k now.
SoFla yes she's been running for a couple years now. Originally I was trying to guess the RPM's off the graph since it was set on speed not rpm. She isn't running worse at all still as strong as day one. My compression is 10.7:1, I know I could have gone higher but that was what I was told would be safe on pump gas and spray for a street car. Also I have an SLP lid and stock MAF on the induction side. I was wondering if I was bottle necked there also but I monitored my KPA and it only dropped to 99/98 from 100 at WOT.
Last edited by dkeets; 11-18-2016 at 11:41 PM.
Reason: Update
To me that graph actually looks really good. Trying to see where 5252rpm is I think the graph stops right around 6100rpm. It needs to be revved higher on the dyno to see when it actually falls off. I actually had the same problem. How high do you rev it now/rev limiter? I would definitely say a better lid/MAF would help. Especially on your motor. Maybe a FTP 104 lid & 100mm MAF.
SoFla I haven't seen the tune but seems like the limiter is set around 6k ish and my shift point is around 5800/5900 ish. This video probably isn't an apples to apples due to the nitrous being on but I think it shifts a little lower off the bottle. Also speedometer is off due to the MT pros out back.
One thing that comes to mind is maybe the rev limit was set there because of the nitrous? Not sure if motors on the bottle like to be spun out instead of just getting to the next gear. Again the power graph looks good N/A. I think it would pull clean to at least 6500. But of coarse I can't say I would do that. N/A I would but not on the bottle. Motor seems to run strong. I think most would agree to get that SLP lid & stock MAF out of there.
i have same cam but on a 110. mine peaks around 6,000 or alittle higher and drops off power pretty bad,but i think a lot of it is because it is on a 110 instead of wider lsa. when i first built the motor i ran a small lid/stock maf.i put on a bigger 104 lid and bigger maf and it picked up around 20 rwhp.wherever it peaks,it should be shifted around 500 rpm or so higher, i would think that setup should be shifted around 6,500 or so.
SoFla n Slow trap thanks. I'm still not sure if my maf/lid is the problem. I checked and st wot she's not really going on a vacuum. But also I've heard of issues with tuning aftermarket mafs and my tuner said he would have put my car on a sd if the stock maf became an issue. Maybe a 102 intake could help but not sure if it would be worth the coins seeings how I already have the 92. Maybe I'll try to get a video of my kpa at wot to see what you guys think.
Also Slow Trap thanks for sharing about your cam and set up. Sounds like your overall curve is similar to mine. I hope others with this cam step in and share their experiences... if you can it would be awesome if you could post your graph for comparison also Slow Trap!
11-17-2016, 09:24 PM
Texas Speed 244/248 .612/.615 Cam 
