mods question

[blacksupra]

I just bought a 87 supra turbo 5 speed. The engine has been rebuilt and the only mods are K&N, 3" exhaust, and 3"Dp not installed yet. Whats should I do next?
I'd like to know if I'm going to hit fuel cut when i put the 3" exhaust and DP.
What should I do next?
bov, lexus afm with 550 injectors, MHG,or arp heads bolt.

 

[91suprat]

if you dont raise the boost at all you shouldnt hit fuel cut. but if you do raise the boost the lex and 550 will work fine. it is a good idea to ditch the stock hg for a mhg and arps. but a bov is a good idea also, so you should do all of the things you listed. as fo order i would do the hg first as you want a solid platform to begin modding.

 

[evildoer]

you can shim the wastegate alilttle and run 9-10 psi wit out fuel cut if you have no leaks

 

[shaeff]

dont shim the wastegate, just get a manual boost controller from doc. jonez!!!

-shaeff

 

[IHI-RHC7]

Actually, shimming the wastegate allows for more boost than a mbc.
Even with my Cooleeze DP and exhaust, the ct won't make over 10 psi over 4K without shimming the gate.
Even still I can't get much over 10 past 5K. Grrr.

 

[shaeff]

really? thats odd... i bet your wastegate actuator diaphram has called it quits.

-shaeff

 

[IJ.]

really? thats odd... i bet your wastegate actuator diaphram has called it quits.

-shaeff

If the diaphram dies it will make MUCHO boost right up till either the turbo won't flow anymore or the motor takes a dump. (think about it if the gate's not working it's never opening)(MBC is a controlled leak to get more boost, dead diaphram is a bigger leak)

 

[shaeff]

perhaps not dead, but getting weak? i read somewhere that when the actuator starts to go, ya gotta shim it and use a MBC to boost more. maybe its stuck open a little and shimming it closes it back up?

-shaeff

 

[91suprat]

with an older actuator the spring sometimes cant hold it shut throughout the power band and shimming it adds more resistance to the spring thus holding the wastegate closed and producing more boost.

 

[shaeff]

^thats probably what i was thinkin...

-shaeff

 

[IJ.]

Ahhh that makes more sense !