Impreza under boosting?
 

Hello, i bought a 1993 WRX Impreza (JDM Import) on Sunday and everything seems fine except it only boosts to 10psi and the clutch is starting to slip now and again which im going to fix soon.

I have read that standard JDM Imprezas should be boosting at 15.95 psi? is that right? So obviously i would like to have it boosting atleast standard. I have cleaned the boost solenoid using the guide on here by connecting the green clips and spraying it through with brake cleaner. I have also sprayed the MAF sensor to try clean that. I have had a look round to see if there is any boost leaks on the hoses but couldnt find any but i havnt had time to buy some bungs yet and pump it up with a compressor and spray soapy water. I also havnt checked for an exhaust leak yet. Other than these points what else could be causing it to under boost? If i check all of these things and everything is fine would you consider a MBC?

Also it is fitted with a 3 inch Apex system and decat. If i was to get an induction kit would that bring the boost up or would the solenoid restrict it?

Any advice would be great because im fairly new to turbo cars, but mechanically minded so it wont be like talking to a brick wallhttp://images.ibsrv.net/ibsrv/res/sr...ons/icon12.gif

......also how do i remove the 110mph restrictor and what is a safe boost to be running a JDM import on. Cheers

You need a little adaptor that fits either on the back of the speedo or between the two halves of the speedo cable. That'll convert the speedo to mph and remove the limiter.

Cheers, so if that was to use the adapter i could leave the current JDM clocks in and it would just convert it so that "30" on the clocks would be 30mph and not 30kph?

..or would i need Mph clocks too?

I found this....

Q What’s the Common Causes For Underboost?

Solenoid lazy or not working – Cure ( Clean (use carb cleaner or simmilar) or replace the solenoid)

Restrictor Pill not fitted / size incorrect – (Cure ensure the restrictor pill is fitted (2 port) if so on 2 port reduce the restrictor size and on the 3 port increase the port size to increase boost to reach normal safe max boost level.

Weak or broken actuator spring – Cure ( Replace the actuator ) this can be tested for by connecting the turbo outlet straight to the actuator and seeing what max boost level you get this should be about 0.5 BAR

Leaking exhaust manifold and/or up pipe The production of boost via the turbo is very dependant on exhaust gas flow over the turbine so if there are any leaks in the exhaust pre turbo your spool and peak boost will be affected, obviously the larger the exhaust leak the worse the effect on the turbo output will be.

When it says increase increase the port size does it mean the "Solenoid mod" where you drill the port which goes to the actuator with a 3mm drill bit to increase the port size? Cheers

If you get a new one it should come with a 'MPH' sticker which you put over the KMH label on the speedo. 30kph will be 30 mph.

Something like this.

http://www.type-ra.co.uk/shop/subaru...ter-p-302.html

Just make sure your's is cable. It should be.

got one of those in shed if your interested

How much? Im not too fussed about one at the moment like im focusing on getting the boost right first and making it look a bit nicer!

Hi mate is the one you got for a ver 4??

Hello and welcome.
I would stay well clear of a MBC, is the boost gauge your using reliable a lot of the cheaper one give false readings, also if it us underboosting and you find the fault it will destroy your clutch if its already slipping and probably your flywheel.
Get some pics up.

Hello, Im going to get the clutch fixed asap. What if i find there is no faults and its just running 10psi but standard JDM imports run 15.95psi. How would i solve this? How can i increase the boost in the safest way? Cheers

Also what pictures are you wanting?

Loui

Well unless the loui in your I'd is the beginning of Louise ones of the car will do fine.

If it is only running 10 psi then there will be a fault.
Have you checked for error codes?

No not yet, a local remapper said he can plug the computer in and go for a spin and the computer will tell him the exact boost its running at etc. and any faults. So im getting him out next week. I cleaned the solenoid and MAF out yesterday properly with brake cleaner and its boosting 11psi now. Do you reckon its had a different ECU in with a limit of 11psi boost? Cheers

I doubt someone will have changed the ecu but you never know.

If you have a look at jollygreenmonsters website there is a help page which tells you how to check the fault codes and reset the ecu.

Check the fault codes, reset the ecu go for a drive then check the codes again, it may have some codes stored from many moons ago.

There's nothing wrong with it then, as thats roughly what it should be boosting at as standard.

15.95 is definitely not the boost level for the 92-94 cars.

Cheers for the info guys il check that site out. Right then i guess there is nothing wrong with the car then and i have just read the wrong info. Where would you go from here if you where me? Its already de-catted, im going to service it, also get a panel filter ir would you go induction kit? Im going for a different intercooler too. Would you go bigger top mounted or front mounted and last but not least injectors and remap/chipped ecu?!? What injectors and ecu or chip etc.? I dont want stupid bhp just around 300bhp if i can. Whats safe to go to? Help is much appreciated, Thanks Loui

not sure ill take a pic in the morning for you and £15 plus postage mate

Hi ok pal I need one that's for a ver4 or later, if it is I'll take it thanks..

this is it bobby fits on gearbox mate

http://i1165.photobucket.com/albums/...y/DSC_0216.jpg

http://i1165.photobucket.com/albums/...y/DSC_0215.jpg

See if you can pick this up, since you have de-catted. Its a simple swap for the ECU you currently have:

http://www.ebay.co.uk/itm/impreza-tu...item3f180216e1

as posted in the other thread:

WRX/STi Saloon ECU's 2C, U8, W6, W9 - As above, 11.47psi held to redline. Fuel-cut 14.57psi (240ps=236bhp)
WRX (1995/96) ECU Z4 - 12.71psi, dropping to 11.78psi @ 6600rpm. Fuel-cut 15.65psi (260ps=256bhp)