why did I make no power???
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why did I make no power???
Previous set up was cam only TR 230, all bolt ons, hooker long tubes, custom 3" y pipe thru a cutout, ls6 intake, jantzer TB,steel flywheel, single disk kevlar, 12 bolt w/4.30's. I put down 393 hp and 385 tq. The car peaked at about 5800 and pulled strong all the way till 7000.
Well, I went to the dyno yesterday with my new set up. The drive train was the same but the motor was completely different.
Now I have the Futral F11 cam on a 114 lsa, AS Stg2 5.3's, HS rockers, Comp stock replacement lifters, 7.4 pushrods, Rollmaster dbl chain, TR ported oil pump, 28.8 injectors, March fluid underdrive pulley.
I put down a whopping 385hp and 363 tq. I peaked right about 6k and then dropped off like I had valve float at 6400. I am completel confused with this. My tuner was adding and subtracting fuel and timing trying to get my car to react and it never really did. The drastic changes that he made only netted a +/- 2-3 hp difference. With the changes that he made, you would expect to see a 10-15 hp drop or gain at least.
Any and all help is greatly appreciated. It really sucks to spend all that money and lose power over a cam only setup.
Andy
Well, I went to the dyno yesterday with my new set up. The drive train was the same but the motor was completely different.
Now I have the Futral F11 cam on a 114 lsa, AS Stg2 5.3's, HS rockers, Comp stock replacement lifters, 7.4 pushrods, Rollmaster dbl chain, TR ported oil pump, 28.8 injectors, March fluid underdrive pulley.
I put down a whopping 385hp and 363 tq. I peaked right about 6k and then dropped off like I had valve float at 6400. I am completel confused with this. My tuner was adding and subtracting fuel and timing trying to get my car to react and it never really did. The drastic changes that he made only netted a +/- 2-3 hp difference. With the changes that he made, you would expect to see a 10-15 hp drop or gain at least.
Any and all help is greatly appreciated. It really sucks to spend all that money and lose power over a cam only setup.
Andy
#4
Originally Posted by haole_boySS
Previous set up was cam only TR 230, all bolt ons, hooker long tubes, custom 3" y pipe thru a cutout, ls6 intake, jantzer TB,steel flywheel, single disk kevlar, 12 bolt w/4.30's. I put down 393 hp and 385 tq. The car peaked at about 5800 and pulled strong all the way till 7000.
Well, I went to the dyno yesterday with my new set up. The drive train was the same but the motor was completely different.
Now I have the Futral F11 cam on a 114 lsa, AS Stg2 5.3's, HS rockers, Comp stock replacement lifters, 7.4 pushrods, Rollmaster dbl chain, TR ported oil pump, 28.8 injectors, March fluid underdrive pulley.
I put down a whopping 385hp and 363 tq. I peaked right about 6k and then dropped off like I had valve float at 6400. I am completel confused with this. My tuner was adding and subtracting fuel and timing trying to get my car to react and it never really did. The drastic changes that he made only netted a +/- 2-3 hp difference. With the changes that he made, you would expect to see a 10-15 hp drop or gain at least.
Any and all help is greatly appreciated. It really sucks to spend all that money and lose power over a cam only setup.
Andy
Well, I went to the dyno yesterday with my new set up. The drive train was the same but the motor was completely different.
Now I have the Futral F11 cam on a 114 lsa, AS Stg2 5.3's, HS rockers, Comp stock replacement lifters, 7.4 pushrods, Rollmaster dbl chain, TR ported oil pump, 28.8 injectors, March fluid underdrive pulley.
I put down a whopping 385hp and 363 tq. I peaked right about 6k and then dropped off like I had valve float at 6400. I am completel confused with this. My tuner was adding and subtracting fuel and timing trying to get my car to react and it never really did. The drastic changes that he made only netted a +/- 2-3 hp difference. With the changes that he made, you would expect to see a 10-15 hp drop or gain at least.
Any and all help is greatly appreciated. It really sucks to spend all that money and lose power over a cam only setup.
Andy
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The rockers are 1.7, the air fuel was in the 13.5 range no matter what was changed with HP tuners. Grannysshifting did the tuning and he is stumped too. He was making big changes with the A/F and timing and it would only yield a 2-3 hp difference.
I am assuming valve float because of the way the power dropped off up top. It was like the clutch was pushed in. Unfortunately, I am not totally sure what springs I have. Acording to the posts that Jay @ AS has made, I am pretty sure I have either the Comp 977 or 978's.
As far as valve train geometry, I tightened the rockers up to 22 ft lbs, thats all.
I assume the pump and filter are ok since the can never tried to go lean even when granny richened it up.
I was "told" by Jay that the heads would yeild 11:1 compression. I am using hardened 7.4 pushrods, HS 1.7 rockers, TR55 plugs. The cam is a Futral F11 227.9/230.4 576.3/597.2 on a 114 lsa, +4 degs of advance.
I am completely stumped. Its like I put on a set of stock 5.3 heads and not the stg 2 port job heads that I paid for.
I am assuming valve float because of the way the power dropped off up top. It was like the clutch was pushed in. Unfortunately, I am not totally sure what springs I have. Acording to the posts that Jay @ AS has made, I am pretty sure I have either the Comp 977 or 978's.
As far as valve train geometry, I tightened the rockers up to 22 ft lbs, thats all.
I assume the pump and filter are ok since the can never tried to go lean even when granny richened it up.
I was "told" by Jay that the heads would yeild 11:1 compression. I am using hardened 7.4 pushrods, HS 1.7 rockers, TR55 plugs. The cam is a Futral F11 227.9/230.4 576.3/597.2 on a 114 lsa, +4 degs of advance.
I am completely stumped. Its like I put on a set of stock 5.3 heads and not the stg 2 port job heads that I paid for.
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I dont know about the "PE" or not. The guy doing the tuning knows his ****. And yes, the cat over temp was off. I am going to re-torque the rockers and change to a tr-6 plug.
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I just recently dynoed on Friday and it was hot as hell. The time before when I dynoed was almost a year ago and I dont remember if it was hot or not.
Either way, it wasn't hot enough for me to lose 35-40 hp. At least I wouldn't think so.
Either way, it wasn't hot enough for me to lose 35-40 hp. At least I wouldn't think so.
#12
Please keep us posted on this. I am having the same problem but no drop off at high rpm. Mine makes power all the way to 6800. But I'm short at least 30hp. I'm running a 5.3 that has been milled .020. 7.4 PR HS rockers. I swung the timing from 32 to 24 and there was only a 3hp difference.
Did you do the wire mod by chance? Where you move the computer wires out of the engine bay a through the fender?
Rob
Did you do the wire mod by chance? Where you move the computer wires out of the engine bay a through the fender?
Rob
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Originally Posted by haole_boySS
I just recently dynoed on Friday and it was hot as hell. The time before when I dynoed was almost a year ago and I dont remember if it was hot or not.
Either way, it wasn't hot enough for me to lose 35-40 hp. At least I wouldn't think so.
Either way, it wasn't hot enough for me to lose 35-40 hp. At least I wouldn't think so.
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Originally Posted by LEATHL_WS6
Did you do the wire mod by chance? Where you move the computer wires out of the engine bay a through the fender?
#15
Originally Posted by Magic Chicken
Never heard of this, what is it supposed to do? Have any websites handy for more info?
Rob
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Nope, I never did the wire mod. Grannysshifting also turned down my timing from 30.5 degs to 24 degs and only had a 2-4 hp difference. I dont recall what the IAT was but with 2 huge fans blowing against the air dam it couldn't of been that hot. We were in a Air-conditioned garage and the exhaust was going outside.
Like I said, I made 394 385 cam only with the TR 230. I dont remember the air temp that day, but I know it was summer time. Now that I have changed to a bigger cam (Futral F11) and AS 5.3 heads I lost power? I can't swallow that I would lose that much from just IAT. The heads would have to give me something right??
Like I said, I made 394 385 cam only with the TR 230. I dont remember the air temp that day, but I know it was summer time. Now that I have changed to a bigger cam (Futral F11) and AS 5.3 heads I lost power? I can't swallow that I would lose that much from just IAT. The heads would have to give me something right??
#17
I'll agree with you there. Your in the same boat I'm in. I went from some crappy heads that flowed 280 10.5:1 at best compression 224 228 cam and made just over 400rwhp. Now I have a set of 5.3 heads flow 300 that have been milled .020 for 11:1 cr. 231 237 cam and made 400rwhp. Just don't seem posiable. Temp I know were similar for me, I was on the same dyno, same guy running it. I pulled 10% fuel from PE and the AFR did not change? COT was off.
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I would check lifter preload. You may have no float, but the valve open and closing events may be mushy from too much preload, or opening late and closing early from not enough preload.
#20
If hes running HS rockers like me there is no adjustment. Just torque them down. I have checked mine from 0 lash to 22ftlbs is between 1/4 and 1/2 turn. Seems right to me. I'm running a 7.4 prod.
I know the 231 makes power thats why I'm dumbfounded. I'm checking into my computer being bad. Everything else seems to check out.
I know the 231 makes power thats why I'm dumbfounded. I'm checking into my computer being bad. Everything else seems to check out.