Todd
Active Member
- Thread starter
- #1
I own a built/sleeved 2016 GT/6r80. It has an older LPF twin setup with 6467s and an upgraded Bell intercooler. It runs stock manifolds and exits a 3" system with MBRP Race-series mufflers.
On the dyno, it made 1002whp, but it took 23 psi to get there and we had what appeared to be some valve float.
Since the engine has aftermarket valve springs, we have it a look over. Though I don't know which turbine housings were on the setup, they were definitely quite small so, thinking it could be a factor, I swapped them for a pair of 1.06 AR housings.
Immediately, it was obvious it took longer to spool and power moved way up in the RPM band. Today, I took it to the dyno to see what improvement the housings may have had. Well, the curve looked like a centri - a steady ramp that kept rising but never peaked, and it only generated 13.xx psi before we ran out of RPM.
My tuner, who is very reputable and has my trust, said the housings are the problem; they are too large.
On a side note, it barely generates a few pounds of boost on the transbrake.
We swapped boost solenoids to rule out an issue there. Nothing.
I am not terribly well versed in turbos. This is my first turbo car after having a TVS and NA strokers before that.
Is this indicative of a boost leak? Do you think the housings are too big? Next step down would be .82 AR. I don't mind the swap, but I want to rule out any possible issues first.
I expected a shift in power and curve, but obviously not like this.
Thank you.
On the dyno, it made 1002whp, but it took 23 psi to get there and we had what appeared to be some valve float.
Since the engine has aftermarket valve springs, we have it a look over. Though I don't know which turbine housings were on the setup, they were definitely quite small so, thinking it could be a factor, I swapped them for a pair of 1.06 AR housings.
Immediately, it was obvious it took longer to spool and power moved way up in the RPM band. Today, I took it to the dyno to see what improvement the housings may have had. Well, the curve looked like a centri - a steady ramp that kept rising but never peaked, and it only generated 13.xx psi before we ran out of RPM.
My tuner, who is very reputable and has my trust, said the housings are the problem; they are too large.
On a side note, it barely generates a few pounds of boost on the transbrake.
We swapped boost solenoids to rule out an issue there. Nothing.
I am not terribly well versed in turbos. This is my first turbo car after having a TVS and NA strokers before that.
Is this indicative of a boost leak? Do you think the housings are too big? Next step down would be .82 AR. I don't mind the swap, but I want to rule out any possible issues first.
I expected a shift in power and curve, but obviously not like this.
Thank you.
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