Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Jim Simms]

The max PSI I have gotten from my 91 XR2 is 5.  As I have written before, I did have an issue with slack in the throttle cable, which did keep the turbo from engaging. After temporarily taking up the slack (as I look for a throttle cable for cruise control) the boost returned. Still, the pressure never goes past five.

Ok techies, here is you time to shine.  If the wastgate is internal in the turbo, and is only holding 5 PSI and then opening, is it a problem with the turbo or the waste gate accuator which can adjust the PSI?  Can you buy a new accuator which can be adjusted to 8, 10, or 14 PSI?

[Rocketman]

You will want to get an aftermarket boost gauge to accurately tell you how much boost you are running. I have had XR2's where the gauge read dead accurate, and I've had ones where it read 2-3 PSi off.

You gauge may say 5psi, it could be 8, lol. Stock boost should be ~6-9psi.

The boost is fixed by the wastegate spring, but you can manipulate what the wastegate "sees" by using a manual boost controller. You can run ~10lbs (Remember - don't trust the stock gauge!) on a stock computer and up to 16psi with a chipped ECU. If you search here on the forum you'll find plenty of info on boost controllers & related mods.

You'll have a totally different car at your hands when running higher boost.

[Jim Simms]

Thanks for the info, as usual.  I can feel the boost back off when the needle reads 5, but it might not be accurate.
Where does a person test the boost ? Where is the guage attached?
How does the manual boost work? Is it manually adjusted from inside the car?
The longer I keep the car, the more likely it will get chipped and go faster.

[Rocketman]

The gauge installs in the cabin. You will need to run a vacuum line to the engine bay & tee it into an existing vacuum line.

The boost controller acts like as a sort of pressure regulator, "fooling" the wastegate. There's a lot of info out there on these, look for the "ball-spring" type manual boost controllers. (google is your friend here )

The boost controller should install in the engine bay, keeping the hoses to and from it as short as reasonably possible. Running them into the cabin will cause boost spike issues. You'll have to dial it in, best done on a quiet remote road where you can pull over and make adjustments as needed. Once it is dialed in though you can leave it be.

[Kev93]

Does anyone ever have any luck with a electronic boost controller system? 

I'm kind of interested in keeping an ability to back off the boost while running if possible.

Is it the expense that's at issue here, or the longer lines you speak of ... or something else?

(Sorry I'm such a newb...)

[Rocketman]

There are multi-stage manual boost controllers if you would like to switch levels. I had one (still have, but it's disconnected) I ended up leaving it at highest boost all the time and adjusted my driving habits.

I have seen some folks install the manual boost controllers. Here are the things I've noticed with them:
-A stock, unported wastegate has a hard time keeping a solid boost level when you have things like exhaust & intake done, this can cause the EBC to go crazy (see: boost creep)
-The stock turbo can spool very quickly, faster than some systems can respond to resulting in spiking
-Significant expense compared to manual boost controller (maybe not so much anymore?)

The EBC mounts a solenoid in the engine bay which allows you to keep lines short still