boost drop off????
 

ok i hit 9psi and then around 5500 it slowly drops back to like 7psi at around red line. is that normal or do i need a helper spring?????

Assuming you're using an MBC or straight up wg can - a helper spring can resolve some of that. It helps to make it adjustable (threaded rod) so you can make changes to the spring tension.

yep normal, welcome to the GReddy kit.

Has anybody just replaced the can? I do have the helper spring and all that, but sheesh.

I've recently been fighting this same battle myself, in the quest for a nice, consistant 14 PSI or so. With the MBC alone, my setup typically will spike to 15 and then settle down to maybe 11 or 12. Ridiculous.

I've done a preliminary helper spring setup, but all I seem to have accomplished thus far is to move the spike upwards a bit.

I used what I felt was a moderatly sized spring, not wanting to go too tight right outta the gate. I can't really say that it helped much- I'm still spiking... Base boost (with the MBC bypassed) went from about 5.5 PSI to 9 PSI. Relatively speaking, are others using stronger springs than this?

My helper puts my unassisted boost to abou 9psi as well.

I haven't gotten anything close to flat. I was seeing ~2psi fall after peak boost. The helper spring reduced that to just over 1psi. :dunno:
dotted line = boost

Hook the mbc feed line to the coldside of the intercooler..

took you 2 years to post your 1st post
in a 4 year old thread.

Should we expect the next post by 2017?

lol, how is this post even possible?

he will answer your question in 4 years

I joined while back helping my buddy with his 91 turbo. I sold my evo 9 went with a gsxr 600 now im rocking my turbo miata.. And how can you hook up the mbc feed to the coldside of the intercooler? Just drill and tap for a 1/8npt barb in the piping after the intercoolerm before the TB.. I did it a while back and got another 1.5psi till redline..

Idk why you guys just gotta hack on someone just cuz they havent posted yet. Im not a newb. Lol ive been boostin for 5 years.. And tuning evos for the past 3.. Lets keep on topic from now on ;)

I joined while back helping my buddy with his 91 turbo. I sold my evo 9 went with a gsxr 600 now im rocking my turbo miata.. And how can you hook up the mbc feed to the coldside of the intercooler? Just drill and tap for a 1/8npt barb in the piping after the intercoolerm before the TB.. I did it a while back and got another 1.5psi till redline..

Idk why you guys just gotta hack on someone just cuz they havent posted yet. Im not a newb. Lol ive been boostin for 5 years.. And tuning evos for the past 3.. Lets keep on topic from now on ;)

3 years oh shit you must be a tuning legend.
Everyone tunes cars here. literally like 90% of the boosted people here. tuning an evo with ecuflash/evoscan is fucking cake. I'm serious.

Welcome to the jungle. :D

OAAlright man.,i never said I was the shit. Lol calm down its just the internet

Lol funny stuff

My girlfriend tunes all my cruise and 3/4 throttle cells while I drive to the shops. So...Yah.

Dann

Amak87, I think the thing that is most surprising is you pick a random thread, that's been dead for almost 5 years, and post a random comment in it. It's sort of like digging up a body to have sex with it, except everyone can see you doing it.

Haha ya bro... Just like raping a dead body. Spot on with that analogy.. Lol

I've just dug the dead body up myself and had a go, not good, I don't recommend it.

Anyway, seriously, got similar issues and found this thread, I know its old but its on topic.
4th gear WOT pull spools ok to 10psi at 3250rpm then drops off to 8.5psi at 4350rpm then picks up again to 10.5psi at 5750rpm. Did you guys still think its likely a wastgate creep ?

try adding .25 inch to the length of the pivot arm on the wastegate's valve shaft.

corky

https://www.miataturbo.net/attachmen...ine=1459359452<br >

Sorry not great with the tech terms, by pivot arm do you mean the arm coming off the spring? Lengthen it ?
I had this set with a little pre load. If I lengthen it the wastgate sounds lose with no load from the spring ?

He means make the arm on the turbo wastegate longer, then preload the can threaded shaft to match.

Will increase the torque applied to the wastegate, hopefully keeping it from opening before it's ready.

Ah ok, thanks. Makes sense 👍

It looks like you're missing a c clip :dunno:

Attachment 183780

Well spotted, but it was just after I'd tried unwinding the arm before I re-assembled and realised it wasn't the right thing to do as the WG preload had gone. It's back to where it was now. Will double check my preload and route EBC signal from after the IC but before the TB, thanks very much for your help. Much appreciated 👍