Looking for some info on DD with a 600-700hp truck

kawi600

kawi600

got Coal for Christmas
Joined
Jun 9, 2008
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Looking for someone with a 160hp auto truck thats done up the trans, motor and turbo past where Im at now (about 400-ish) to 600-700hp.
Im getting really crappy low end response and haze. Could be normal for all I know Ive never driven another with mods.
Im close to doing a hamilton 12v head OR installing twins and cutting valve seats on my OEM head and decking the head flat so the valve protrusion is stock again.. then go with stock gasket on orings. Its got .015 deck and .020 oversize HG now. might be part of the problem, heck if I know. :doh:
Just trying to decide if its worth it. Cant see how the haze and low end can get worse but you never know. gettin 8mpg city / 12mpg highway right now, its fubar'd for sure.
Ive had everything gone thru except the top end and valves at this point.
I hear you lose some swirl on a ported head and that might be a concern for a DD that sees a lot of empty driving when its not toy hauling in the summer.
The cam rate and lift probably plays into the swirl also.. might be boned already at the low end of RPM
 
have your injectors tested, check fuel filter, OFV valve, pretty much check your whole fuel system.

Other than that idk what to tell ya. I dont have a whole lot of low end responce but that is because im running a single 66mm turbo and 26* timing. right now im averaging 16-15mpg thats being very heavy footed.
 
been there done that. pump was benched. injectors are weston's and ofv is torktek. I get pretty solid 25-35psi.
im running out of things to try. But with that setup adn youre stll seeing 15-16mpg? means somethings off on mine for sure.
 
kawi600 said:
been there done that. pump was benched. injectors are weston's and ofv is torktek. I get pretty solid 25-35psi.
im running out of things to try. But with that setup adn youre stll seeing 15-16mpg? means somethings off on mine for sure.
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yes and that is with a very dirty air filter.
 
Whats your off-idle response like on that truck? Say if youre just pulling away from a stop normal, without building boost first. Mines driving like a damn bread truck, I get people pissed off and they blow around me, lol. alternative is I give it more pedal and more smoke.. hippies up here dont like that much.
 
Check pop pressure again, and give it some more timing. How fast do you drive on the highway? 65mph or 85mph?
 
just dropped the truck off at the shop. Im going with zach hamilton's idea of decking the head a little and cutting the valve seats a little different. Hope to get back the low end power. and stop throwing the fuel out the pipe instead.
If I do twins in the future I might look into the hamilton head again to get the pressures down. This truck just doesnt like an oversize gasket on there.
Dunno how much pressure orings will hold up to reliably.. 65-ish?
 
It's sounds like you have a combination of a few different issues causing the low end power loss and poor fuel mileage. Just keep working with it and deal with the same person about the issue. Good luck to ya!
 
kawi600 said:
just dropped the truck off at the shop. Im going with zach hamilton's idea of decking the head a little and cutting the valve seats a little different. Hope to get back the low end power. and stop throwing the fuel out the pipe instead.
If I do twins in the future I might look into the hamilton head again to get the pressures down. This truck just doesnt like an oversize gasket on there.
Dunno how much pressure orings will hold up to reliably.. 65-ish?
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Considering my stock head gasket with stock head bolts torqued to 130 is holding 55 just fine I would think o- rings could hold 80 and up.

Good luck on getting it figured out. Nobody likes a poorly performing truck. Been there
 
And 26* of timing is pretty hard on the head gasket too.

YOUNG GUNS15 said:
Considering my stock head gasket with stock head bolts torqued to 130 is holding 55 just fine I would think o- rings could hold 80 and up.

Good luck on getting it figured out. Nobody likes a poorly performing truck. Been there
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