Restrictor ring for 1JZGTE

A

atreyu187

New Member
Ok so I'm new to all this so please excuse my ignorance. I recently purchased an IS300 with a 1JZGTE swap. Right now there isn't much done aside from an intake and exhaust. The guy I got it from took quiet a few shortcuts and I have been fixing all the issues the car had.

I finally have it running good after new plugs, coil packs, fuel pump, installing a PS pump, VVT-i solenoid, V-belt and timing belt. Had to do full suspension components as balls joints were shot, bad sway bar bushings and link pins. Then I had to get coil overs as he cut the springs.

Now my issue seems to be it has a bad overboost issue. He had a custom exhaust that is a 3" straight pipe to a magnaflow resonator. It sounds great but I am having an overboost issue as it needs the cat for back pressure.

So till I can get the cash together for my upgrades to the turbo system I was hoping to install a restrictor ring for the time being. I am going to do some work to all this but I am trying to get all the parts to do it at once and no cut corners as this is a fun project for me as it's my first boosted car but seems like I'm trying to fix most of his mistakes.

Now I am having issues finding one of these and was hoping someone could help me locate one. I am going to get a boost controller when I get a new turbo, manifold, wastegate and set it up for a BOV since it uses a recirculated setup right now.

So thanks in advance and if I have any of my info wrong please correct me as I have only had the car a week and doing all this myself.
 
I’m running a full 3inch system on my chaser and a j pipe delete, it’s on standard engine management and running just under a bar of boost,
You sure you are getting over boost cut?
mine runs sweet as a nut and I know if you go anything over a bar of pressure you get fuel cut as the ecu shits itself.
You got a boost gauge maybe worth seeing what she boosting??
 
It is for sure overboosting. It shoots from 9psi to 20+psi between 3500-4500RPM when I give it more then half throttle. I have a buddy I have been talking with that has the EXACT same issue with his car that was fixed doing this but I don't really care for how he did it. He choked the pipe back from 3" to 2.25" with a piece of pipe then opens back up to 3" and it fixed his issue. So it goes from 3" then a foot of 2.25" then back to 3" all I want to do it just put a ring in it. I did seem to have found something that may do the trick.


http://www.garagewhifbitz.co.uk/garage-whifbitz-1068.html

So I think I am going to try to order this but need to have a flange made for my exhaust so I can remove it once I get the cash to upgrade the turbo components.
 
1.3 bar will make the turbo shit itself, I actually had my car on the rollers at whifbitz the end of August with like I say a full 3inch exhaust system,no cat,blitz back box and a custom turbo elbow, and the j pipe delete(which made a big difference to boost pressure on its own) and it was a smidge under one bar at 331bhp, try the restrictor give whifbitz a call and ask them there very helpful and know there stuff, you running a boost controller?
 
Yeh surely a boost controller fail for that mad gains? Leak in the boost vac lines?

Stick a 2.25” flange in after the Downpipe and see if it changes it? Literally a 10 min job, longer bolts, slip it between the exhaust and downpipe. Win
 
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