GTX2867R, FM log mani, 1.8, 8.4cr
#21
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I would have thought a bit more fuel in the ramp up section would cause it to still be burning when the exhaust valve opens and therefore expanding in the exhaust manifold. But that's just a preliminary thought since you brought it up. I'll have a cup of coffee and think about it.
#22
I'm actually a little surprised at the top end, 15psi on a turbo that big with a 1.8L and makes the same torque as my 2554R/stock 1.6L/Begi mani/2.5" exh/13psi from 6000 to redline? I am on E85 but I figured the GTX with a 3" exhaust would be flowing a lot more efficiently than a 2554 in the high revs.
#24
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I'm actually a little surprised at the top end, 15psi on a turbo that big with a 1.8L and makes the same torque as my 2554R/stock 1.6L/Begi mani/2.5" exh/13psi from 6000 to redline? I am on E85 but I figured the GTX with a 3" exhaust would be flowing a lot more efficiently than a 2554 in the high revs.
#26
I would have thought a bit more fuel in the ramp up section would cause it to still be burning when the exhaust valve opens and therefore expanding in the exhaust manifold. But that's just a preliminary thought since you brought it up. I'll have a cup of coffee and think about it.
#27
On my GT3271, I found a lot of spoolage by not running pig rich while it spools. I ran it around 14:1 at 100kPa, 13:1 at 140kPa, etc, tapering to target AFRs when you get to target. That made a very very nice improvement in both driveability and spool. Worth a shot since your posted AFR target table is richer than needed at very low boost.
#33
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I haven't changed anything since that dyno run except some reliability mods. The possible restrictions are the FM log mani, the 70 degree bend in the 3in downpipe about 10 inches from the turbine outlet, the 2" hotside intercooler piping, the intercooler, etc. Everyone so far says my timing is good, but pointers are welcome. Is base timing off or maybe a tooth off on a camshaft? I'm not sure.
It's been parked mostly and I've been busy selling a house. But I'd love some ideas.
It's been parked mostly and I've been busy selling a house. But I'd love some ideas.
#34
I haven't changed anything since that dyno run except some reliability mods. The possible restrictions are the FM log mani, the 70 degree bend in the 3in downpipe about 10 inches from the turbine outlet, the 2" hotside intercooler piping, the intercooler, etc. Everyone so far says my timing is good, but pointers are welcome. Is base timing off or maybe a tooth off on a camshaft? I'm not sure.
It's been parked mostly and I've been busy selling a house. But I'd love some ideas.
It's been parked mostly and I've been busy selling a house. But I'd love some ideas.
2 inch hotside IC piping shouldn't be a big deal either. Again, FM runs 2 inch and its fine. And the standard size for the turbo outlet is 2 inch
Whats your air filter setup? Maybe choking the big azz turbo?
Still puzzling tho. Im still thinking this is the turbo for my goals but if i struggle to hit even 300whp ill be mad asf
Last edited by LownSlow616; 09-05-2016 at 10:14 PM.
#35
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Air filter is of adequate size but is in a poor location. Using NA8 intake manifold and Skunk2 throttle body. 3 inch downpipe is covered in heat shields but I have an old picture from a prior disassembly depicting the sharp turn. It is still many times larger than the turbine outlet so even though it's not ideal I don't know if it could cause a tremendous amount of restriction.
This is the downpipe and manifold (with a different turbo).
This is a good depiction of the difference between the turbine outlet size and the 3in pipe:
Again, the bend in the downpipe (very old pic, many of the surrounding components have been changed or rerouted):
As she sits this morning. Note air filter location far less than ideal.
This is the downpipe and manifold (with a different turbo).
This is a good depiction of the difference between the turbine outlet size and the 3in pipe:
Again, the bend in the downpipe (very old pic, many of the surrounding components have been changed or rerouted):
As she sits this morning. Note air filter location far less than ideal.
Last edited by sixshooter; 09-06-2016 at 08:51 AM.
#36
I haven't changed anything since that dyno run except some reliability mods. The possible restrictions are the FM log mani, the 70 degree bend in the 3in downpipe about 10 inches from the turbine outlet, the 2" hotside intercooler piping, the intercooler, etc. Everyone so far says my timing is good, but pointers are welcome. Is base timing off or maybe a tooth off on a camshaft? I'm not sure.
It's been parked mostly and I've been busy selling a house. But I'd love some ideas.
It's been parked mostly and I've been busy selling a house. But I'd love some ideas.
#40
not even talking about spool tho. there is no reason the HP should be this low
if i had a turbo that big and shiny and was making as much power as ppl with stock engine and gt2560 id lose sleep at night. not even trying to sound like an ***, just trying to pick my next turbo and i cant have this happen to me...
if i had a turbo that big and shiny and was making as much power as ppl with stock engine and gt2560 id lose sleep at night. not even trying to sound like an ***, just trying to pick my next turbo and i cant have this happen to me...