what do you think the "sweet spot" is on a pte70gtq?

[4-71/Z-28]

i was just wondering where this turbo starts to come into its effifiency range? right now im at 25#'s and it feels extremely strong, i was thinking about giving it another pound or two, or a few more degree's of timing, im at 23/21 right now with a dual nozzle razor kit with no knock, besides transitional, the knob is set to 5.5 so i have room to play.

 

[bison]

28-30psi and between 6200 and 6400 rpm. 6500-6700rpm and between 25-27psi. You will never be able to maximize the 70 compressor with a 3 bolt turbo setup. Backpressure starts to get really high over 700hp. TSM has gone 150mph with a 3 bolt though. With your small hydraulic roller application it will most likely really crank at 30-32psi and between 5800-6000rpm. You will need to address the fuel delivery to the rails to run it that hard

 

[RUQWKNF]

I concur with bison.

Most of the heavy hitters play in the 30-32psi range. But as bison said, back pressure with the .85 A/R PTE housing at that boost level is extreme to say the least.

Before you start shooting for 28-32psi range, I would up the timing to 27* in 1st and 2nd and 25* in 3rd & 4th. With boost set at 28-29psi and the alky flowing freely, and I do mean freely. You really are on the ragged edge with a 109 block setup and boost levels over 29psi with that turbo. 4 bolts per cylinder and all.

The most important thing I can tell you, make sure you never see any knock retard when playing at this level. As with 4 bolts per cylinder, it only takes one mistake. Slowly creep up on the tune, don't just go out and crank the knob and dial up 27/25. Make double sure your fuel system is up to snuff. Power capability at that tune 28-32psi and 27/25* is serious. I would say that right now you are just starting to get into sweet spot.

HTH

Patrick

 

[KevinB]

28-30psi and between 6200 and 6400 rpm. 6500-6700rpm and between 25-27psi. You will never be able to maximize the 70 compressor with a 3 bolt turbo setup. Backpressure starts to get really high over 700hp. TSM has gone 150mph with a 3 bolt though. With your small hydraulic roller application it will most likely really crank at 30-32psi and between 5800-6000rpm. You will need to address the fuel delivery to the rails to run it that hard

What's wrong with the stock rails where do you think the limitation is? I have not noticed anything yet (knock on wood). Would like to upgrade but it's not in the budget at this time.

 

[RUQWKNF]

I think he meant upgrading the stock fuel system hard lines from stock OEM lines, over to larger diameter lines with an adequate fuel pump to take care of biness.....

We ran a modified stock fuel rail into the low 9's years ago, but had larger feed and return lines to go with the Weldon pump.

Patrick

 

[bison]

What's wrong with the stock rails where do you think the limitation is? I have not noticed anything yet (knock on wood). Would like to upgrade but it's not in the budget at this time.

Not sure but most arent hitting mph like you are on the stock rails. Usually dual fed rails and an external regulator

 

[KevinB]

I think he meant upgrading the stock fuel system hard lines from stock OEM lines, over to larger diameter lines with an adequate fuel pump to take care of biness.....

We ran a modified stock fuel rail into the low 9's years ago, but had larger feed and return lines to go with the Weldon pump.

Patrick

I have a -8 feed and -6 return. Ran a Weldon 2025 last year and it worked good. Switched to an Aeromotive Eliminator this year for better drivability plus the Weldon was borrowed.

Not sure but most arent hitting mph like you are on the stock rails. Usually dual fed rails and an external regulator

I usually check the plugs after every other run. So far so good. The Champion rails would be a nice upgrade though. We have a 150+ mph TSM car up here that ran stock rails last year and I would think Dick's 8 second TSM run was probably on stock rails because that is all that was legal at the time. I'd like to see someone with individual egt's on each cylinder to get some hard evidence on how much better the Champion's fueling is.