Restrictor plate in BEGi exhaust
03-09-2015, 06:37 PM
#62
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No it doesn't.
Most of my stock motor builds creep up to 17 or 18 psi at redline intentionally using ebc and peak torque is still below 5000rpm like everyone else's.
Last night I spent close to an hour pulling torque out of the 4500rpm area of a VVT turbo NA, which made 280rwhp, because that's where peak torque waseven with 100% wastegate Duty Cycle from 5500rpm onwards.
We had to use VVT, timing and boost to pull that 4500rpm peak out of the tune, because VE.
Dann
Most of my stock motor builds creep up to 17 or 18 psi at redline intentionally using ebc and peak torque is still below 5000rpm like everyone else's.
Last night I spent close to an hour pulling torque out of the 4500rpm area of a VVT turbo NA, which made 280rwhp, because that's where peak torque waseven with 100% wastegate Duty Cycle from 5500rpm onwards.
We had to use VVT, timing and boost to pull that 4500rpm peak out of the tune, because VE.
Dann
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03-09-2015, 06:53 PM
#64
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The engines torque output doesnt give a **** if its creep due to a low flowing wastegate port or due to a flapper being intentionally closed with EBC.
Yeah Im creating creep intentionally. The above example is a built engine, raced with a 5 speed, so we are using what is effectively creep to keep torque flat as possible but below a threshold.
Even using a huge amount of creep torque peak is still in the normal spot and this is literally a good thing for performance, and not a bad thing for reliability, unless you have some issue like a fuel system that cant keep up or a lead foot and no driver skills.
Dann
Yeah Im creating creep intentionally. The above example is a built engine, raced with a 5 speed, so we are using what is effectively creep to keep torque flat as possible but below a threshold.
Even using a huge amount of creep torque peak is still in the normal spot and this is literally a good thing for performance, and not a bad thing for reliability, unless you have some issue like a fuel system that cant keep up or a lead foot and no driver skills.
Dann
Last edited by nitrodann; 03-09-2015 at 07:04 PM.
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03-09-2015, 07:17 PM
#65
The engines torque output doesnt give a **** if its creep due to a low flowing wastegate port or due to a flapper being intentionally closed with EBC.
Yeah Im creating creep intentionally. The above example is a built engine, raced with a 5 speed, so we are using what is effectively creep to keep torque flat as possible but below a threshold.
Even using a huge amount of creep torque peak is still in the normal spot and this is literally a good thing for performance, and not a bad thing for reliability, unless you have some issue like a fuel system that cant keep up or a lead foot and no driver skills.
Dann
Yeah Im creating creep intentionally. The above example is a built engine, raced with a 5 speed, so we are using what is effectively creep to keep torque flat as possible but below a threshold.
Even using a huge amount of creep torque peak is still in the normal spot and this is literally a good thing for performance, and not a bad thing for reliability, unless you have some issue like a fuel system that cant keep up or a lead foot and no driver skills.
Dann
When I ran the 6758 on just the 7psi spring pressure, it peaked at 12psi at peak power and tapered off from there.
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03-09-2015, 07:21 PM
#67
The engines torque output doesnt give a **** if its creep due to a low flowing wastegate port or due to a flapper being intentionally closed with EBC.
Yeah Im creating creep intentionally. The above example is a built engine, raced with a 5 speed, so we are using what is effectively creep to keep torque flat as possible but below a threshold.
Even using a huge amount of creep torque peak is still in the normal spot and this is literally a good thing for performance, and not a bad thing for reliability, unless you have some issue like a fuel system that cant keep up or a lead foot and no driver skills.
Dann
Yeah Im creating creep intentionally. The above example is a built engine, raced with a 5 speed, so we are using what is effectively creep to keep torque flat as possible but below a threshold.
Even using a huge amount of creep torque peak is still in the normal spot and this is literally a good thing for performance, and not a bad thing for reliability, unless you have some issue like a fuel system that cant keep up or a lead foot and no driver skills.
Dann
creep is what happens when you can't control it, and it usually happens at peak torqure, because boost usually creates torque.
"intentional creep", is not creep. it's just boost control
basically what Leafy said. you're missing the point
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03-09-2015, 09:03 PM
#71
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After doing dozens of tunes on cars where we need to limit torque for engine and or gearbox reliability, the only way that 'boost creep is bad because boost makes torque' could possibly make sense in this context is if you hadnt calculated a creeping cars torque across the area where it creeps during dyno tuning.
Im putting that to the non believers, and Im asking them to please dispute it.
Dann
Im putting that to the non believers, and Im asking them to please dispute it.
Dann
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03-09-2015, 10:37 PM
#72
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BH2dKeith,
No A/O for you until the cast manifold is in my hands. The pattern has been at the foundry long enough to expect castings within a couple weeks.
Your turbo will need a few mods. You or me? If you do it, you will do it as I suggest.
I will be glad to fix it up, nc. What fuel system are you using? Need EGR?
Sorry about no Christmas card. It was just a bigger risk than I was willing to take.
Hang loose, you are at the top of the list. I'll need to figure out which list that was.
corky
No A/O for you until the cast manifold is in my hands. The pattern has been at the foundry long enough to expect castings within a couple weeks.
Your turbo will need a few mods. You or me? If you do it, you will do it as I suggest.
I will be glad to fix it up, nc. What fuel system are you using? Need EGR?
Sorry about no Christmas card. It was just a bigger risk than I was willing to take.
Hang loose, you are at the top of the list. I'll need to figure out which list that was.
corky
What needs to be done to the turbo to make it fit? Swap exhaust housing to a conventional one instead of the V-band? If so, I can handle that myself if parts are supplied. You had me re-clock the compressor housing and grind a bit on the compressor housing to get it to fit under the old tubular manifold, so I can handle re-clocking of the compressor housing also. If it is more complicated than that, I can send it your direction.
I have an upgraded fuel pump, 1000cc injectors Megasquirt3 and am running E85.
No EGR on my setup.
Probably on top of your **** list right now
If all of this works out, you will end up on my Christmas card list.Keith
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03-09-2015, 10:42 PM
#73
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Keith
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03-09-2015, 11:16 PM
#79
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Someone should probably explain the difference between boost overshoot and boost creep. I'm pretty sure Dann is referring to creep (boost rises with RPM regardless of wastegate spring pressure), while everyone else is referring to overshoot (boost rises rapidly past the wastegate spring pressure which creates torque spikes that can damage stock engines).
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03-09-2015, 11:22 PM
#80
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Thats correct.
Ive never seen overshoot on an MX5 with a T2x turbo or EFR using competent boost control, and CERTAINLY not with only the wastegate can for boost control.
Dann
Ive never seen overshoot on an MX5 with a T2x turbo or EFR using competent boost control, and CERTAINLY not with only the wastegate can for boost control.
Dann
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