Shimming Wastegate

[s.u.p.r.a]

Hey all,

How much boost will (3) 7mm washers add to a stock jdm 7MGTE?

How safe is this?

Thanks for any info,
Alex

[MassSupra89]

Add one shim at a time and take it for a ride, when you hit fuel cut, you have too many washers.

[s.u.p.r.a]

There isn't anything other than fuel cut that I should be watching out for is there?

[MassSupra89]

Don't do it when the turbo is hot, you'll strip the holes out for the wastegate bolts.

Fuel cut will take care of saving your engine from overboost. Remember you could creep to higher boost levels when it's colder, and in higher gears. I'd hit fuel cut occasionally at night on the highway when trying to boost for too long in 4th or 5th gear.

Get an accurate boost gauge(guessing how much above the 8 on the stock gauge does not count) and stay below fuel cut, you should be alright.

Is the car stock? I'd recommend an exhaust before playing with boost levels.

[s.u.p.r.a]

Thanks for the info.

Its an '89 n/a chassis with an '89 GTE swap.

Everything is stock.

It has an open downpipe at the moment until I can get my exhaust welded back on.

[noah89t]

don't do it, buy a boost controller

[ForcedTorque]

don't do it, buy a boost controller

+1

Even a manual Boost controller is much better than shims. I think Doctor Jones has them for like $25, and it is as good as you will need til you do more mods. But, as said before, you should look at intake and exhaust while you do this. Be forewarned, after you do this, you won't want to stop the Mod process

[Frank Rizzo]

guessing how much above the 8 on the stock gauge does not count

Awwww really? :)

Use a mechanical autometer boost gauge.

[JAB89]

don't do it, buy a boost controller
AMEN! I did it. Redoing the HG now.

[Boost Lee]

It's not even that shimming the wastegate is a BAD thing...

But you are putting extra stress on your wastegate spring...
Which, in time, will start giving you issues with boosting and hitting fuel cut at random times.

For the record, if you were to throw (3) 7mm washers on each wastegate actuator bolt...You'd 100% experience FCO.

And a tip for future reference (and a prewarning) - Make sure you've got a healthy headgasket torqued down properly on this motor...
Because more than stock boost is not what a 20 year old headgasket wants to see while cranked down to 50+/- lb.ft's of torque. ;)

-Jeff

[viper92086]

i for one say don't do it, mine was shimmed for a couple of months then i started overboosting and now i think my wastegate spring is messed up because i took the shims out and the wastegate is still actin silly.. but i do have a replacement... just gotta put it on i recommend getting a ebc

[a_sesshoumaru]

besides it is not exact as a boost controller Manual or electronic

[bowsercake]

... stock jdm 7MGTE? ...


HA!

[WhtMa71]

I shimmed mine with one washer on each bolt and it raised boost to ehh...above 8. Im guessing around 10 lol. This on a jdm 7m with the stock HG torqued to 72ft/lbs.