2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

cheap boost until the controller comes

Old Feb 24, 2002 | 03:53 PM
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T2monster's Avatar
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cheap boost until the controller comes

I've got a question, and don't flame me for asking b/c i have blown 2 turbo engines before (one 2.3L ford and one rotary) and i know what detonation sounds like and i know how to avoid it. All ignition parts being sound (Sport Compact MSD ignition, Accel Thundersport 9000 wires, HKS plugs that are new) and with retarded base timing and a supercooled air charge (more on that later) and GOOD (93+) gas, can i cut the wastegate lines, and rely on my A/F meter and boost guages? My friend attempted this (wastegate control removal) w/out an A/F guage and on non-turbo (!!) injectors, and managed to throw an apex seal through the exhaust turbine. I am attempting this only b/c it is a used engine and my j-spec is on the way, and i just finished a rebuild on a pristine '90 turbo. Can this be done, using common sense as a wastegate? I also understand that overboost for any length of time over 5-7 seconds will split a stock apex seal. I was just attempting to gather comments and maybe some similar experiences.

'87 TII
"Hybrid Theory"

RB RCD
dual electric fans
atomization-cooled intercooler
rx7.com full race exhaust
A/F meter, 5" tach, HKS boost guage
'vert wheels
RB 6-puck bronze clutch
HKS super Megaflow intake
MSD,Accel ignition
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Old Feb 24, 2002 | 04:13 PM
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I've a nasty feeling that running with NO boost control will mean a very very short life expectation for the engine, maybe as little as 1 second of boost - those apex seals just cannot take any detonation, even the first 'ping' can be enough. I am running an '89 TII with a simple 'T' bleed to get just below 10psi on an aftermarket gauge. I know that the turbo can make far more than this if the bleed is accidently opened up - a friend of mine did this on his TII and didn't even hear the ping that damaged 2 apex seals the result of which also took out his turbine wheel and meant a new turbo as well as a new engine.
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Old Feb 24, 2002 | 04:13 PM
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Sure. Go right ahead.



Brandon
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Old Feb 24, 2002 | 04:32 PM
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Originally posted by No7Yet
Sure. Go right ahead.



Brandon

u want his seven in parts or something?
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Old Feb 24, 2002 | 04:34 PM
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Scott 89t2's Avatar
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you will hit about 30psi in 1 sec and ka boom...
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Old Feb 24, 2002 | 05:02 PM
  #6  
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Re: cheap boost until the controller comes

Originally posted by T2monster
I've got a question, and don't flame me for asking b/c i have blown 2 turbo engines before (one 2.3L ford and one rotary) and i know what detonation sounds like and i know how to avoid it. All ignition parts being sound (Sport Compact MSD ignition, Accel Thundersport 9000 wires, HKS plugs that are new) and with retarded base timing and a supercooled air charge (more on that later) and GOOD (93+) gas, can i cut the wastegate lines, and rely on my A/F meter and boost guages? My friend attempted this (wastegate control removal) w/out an A/F guage and on non-turbo (!!) injectors, and managed to throw an apex seal through the exhaust turbine.
Seriously NO - the turbocharger is a positive feedback device - you take the exhaust gas, pass it thru the turbine which compresses the intake, which makes more exhaust gas, which compresses more intake - get the idea?... in a very short time you have a GRENADE. Its the wategate that keeps the whole thing in a state of equilibrium, opening when the pressure in the intake is large enough to ovecome the spring in the wastegate can, and allowing some of the exhaust gases to bypass the turbine. Running without a wastegate at all is a recipe for disaster, there is no way that you could react quickly enough to either the EGT or the boost gauge.
PLEASE DON'T DO IT
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Old Feb 24, 2002 | 05:20 PM
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Originally posted by Scott 89t2
you will hit about 30psi in 1 sec and ka boom...

and why am i stupid.. do please explain?!!! all i said was tht if he does that his seven will blow and be in pieces..
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Old Feb 24, 2002 | 05:35 PM
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no ****, that wasnt a stupid comment, it WILL be in pieces.
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Old Feb 24, 2002 | 06:02 PM
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my answer was for the question, not your reply
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Old Feb 25, 2002 | 02:20 AM
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Originally posted by Scott 89t2
my answer was for the question, not your reply
i accept your apology
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Old Feb 25, 2002 | 11:44 AM
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Originally posted by menace


u want his seven in parts or something?
No, I had this big long technical "that would be bad because..." reply written up, but then I realized, the poster is an idiot.

So I didn't bother. Besides, I figured I'd just get some response like "BuT i g0tz an0theR enjun waytiN 2 gO N & I no h0W 2 avoyd detenashun" and he'd blow his engine all to hell anyway.

"Common sense as a wastegate"? Puh-leez. If you had any common sense you wouldn't be considering such an asinine "mod".



Brandon
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