valve float??? or something else?

[TURBOELKY]

when I put my foot through the floor, my car feels like its falling on its face anywhere over 4600 rpm. Wont spin higher than that. Runs awesome until around that rpm. This is at 18 psi. I think its my turbo blowing open the valves, but i've never experienced valve float, i've always had new valve springs on my small blocks, and the last turbo motor I had. Maybe time for new springs?

only other thing is on my scanmaster, my battery volts never really reads above 13 volts, but its not dropping off at that rpm though. I know its not a vaccume leak because all my lines are new, and zip tied. this happened after I installed the alky set up, I was thinking maybe the extra volts running the pump were robbing power from the electronics, but I doubt it

sorry for the long post, anyways, any ideals are welcome! but just trying to get a few more opinions before I start changing things. How high should this thing spin? basically rebuilt, stock bottom end with some .030 forged pistons"I think, they were'nt the cheap speed pro hypers " not sure on cam. just alot of bolt ons.

but before the alky, i'm not sure if I ever floored it to the metal

[johnnyttype]

it def could be time for new valve springs. that would cause a weak top end. r u spraying ur alky on only 18psi? if so how much alky? if u have a scanmaster, what r o2 readings and is there any knock retard?

[TurboDave]

Originally Posted by TURBOELKY

when I put my foot through the floor, my car feels like its falling on its face anywhere over 4600 rpm. Wont spin higher than that. Runs awesome until around that rpm. This is at 18 psi. I think its my turbo blowing open the valves, but i've never experienced valve float, i've always had new valve springs on my small blocks, and the last turbo motor I had. Maybe time for new springs?

only other thing is on my scanmaster, my battery volts never really reads above 13 volts, but its not dropping off at that rpm though. I know its not a vaccume leak because all my lines are new, and zip tied. this happened after I installed the alky set up, I was thinking maybe the extra volts running the pump were robbing power from the electronics, but I doubt it

sorry for the long post, anyways, any ideals are welcome! but just trying to get a few more opinions before I start changing things. How high should this thing spin? basically rebuilt, stock bottom end with some .030 forged pistons"I think, they were'nt the cheap speed pro hypers " not sure on cam. just alot of bolt ons.

but before the alky, i'm not sure if I ever floored it to the metal

If you're shooting alky, do you know what your A/F ratio is? What are you commanding for an A/F ratio? You might be hitting it with too much alky, maybe not enough and getting lot's of knock retard.
Several possibilities.

[TURBOELKY]

zero knock, o2's are 770's up to about 820. Not sure on a/f i'll check next time.

[johnnyttype]

do u still have stock cam in engine? i believe that starts to lose steam somewhere around the upper 4XXX's right?

[WSLN 6]

With my alky on full with a smaller turbo, I couldn't run less than 19pis or it would fall on it's face. Turn off the alky, lower the boost and see how it revs....

[TURBOELKY]

Originally Posted by johnnyttype

do u still have stock cam in engine? i believe that starts to lose steam somewhere around the upper 4XXX's right?

not sure on the cam. The engine has been rebuilt, just not by me. I know no more than it has some decent .030 pistons, and alot of good bolt ons. Never did this at the track when it was in my buddys car, but I was'nt driving so I dont know how high he had it revving. Only difference between when he had it is he had an xfi set up, and a smaller turbo. I have a stock ecm and a bigger turbo. I'm going to try a few things before I jump to the conclusion that its the valve springs though.

[TURBOELKY]

Originally Posted by WSLN 6

With my alky on full with a smaller turbo, I couldn't run less than 19pis or it would fall on it's face. Turn off the alky, lower the boost and see how it revs....

exactly... thats what i'm going to try. like I said, I dont think I put my foot to the floor before the alky, but i'll try that. a buddy is sending me a new chip he programmed, hope that works better for me too.

[cruzn57]

is your tach accurate?
my stocker (WE4) will pull to 5600rpm, with old springs,

[jamier]

my turbo t also had a similar problem with thre car seeming to fall off at wot. I changed my springs woth the compsprings and the car would again pull nice and hard. I suspected it was valve float and my buddy suggestes i changed the springs since they were still stock and the motor had some miles on it. plus the springs are cheap to change, just get a tool if you still have the stockers it'll make life easier for you.