series_mcrae022

Just fitted a boost guage temporaryly to my car, I disconnected the pipe on the right of the three pipes coming out of the inlet manifold and connected the boost guage to the nipple.

When I went on a test run the guage was reading -10psi to -5psi on town driving and reading 17psi on full boost. Has any one got any ideas on why it is reading these figures?, is it because the original pipe is just left hanging?

My car is completely standard.

Scott.T

iTrader: (2)

If it's hitting 17psi I would expect it to be fuel-cutting as the fuel-cut saftey level as probably about 15.5psi on a McRae.

The negative readings seem OK. Should tickover at about -10psi. Should though only read about 11-12psi on full boost.

Maybe the pipe left hanging is bleeding air away and allowing far too much boost.

Connect it to the existing pipes using a T-piece. you can get these from Halfords for abot £1.00 (normally used on winderscreen washer pipework).

series_mcrae022

Thanks Scott T, thats put my mind at rest, looks like a trip to halfords tomorrow is on the cards.

series_mcrae022

Just fitted it now with a proper T-Piece, but tis still reading +17psi at full boost then settling to +16psi, this might be a silly question but would the fuel cut be really obvious? As far as im aware my car is completely standard but I havent had it that long.

Roy.

jameswrx

iTrader: (4)

hi mate, fuel cut would be very obvious, it's like hitting a wall, just shuts the car down v quickly, trust me you'd know
James

GREEN SCOOBY

If its boosting up to 17 psi it can not be standard mate.

teknopete

Just spotted u r post, maybe a bit late but heres my guid to fitting a boost gauge on an early scoob

http://www.scoobymods.co.uk/boostg01.htm

And yeah 17 is a bit high. Have a look in the passenger side footwell under the foot plate, on the off chance that a Schip or similar sensor signal altering hardware has been wired into the ecu.

Pete

Scott.T

iTrader: (2)

Sounds like it might of been Superchipped, as they set them to 16psi and remove the fuel cut limiter, so you will never hit furl-cut even if a hose blows off

There should be a small module near the ECU if thats the case.

If not open the ECU and see if there is a chip in the bottom right corner of the PCB (main connector on the left). You may be lucky and have stumbled accross a PE Phase 1 Conversion.

dominicm

My car was found to have a chip that let it boost to 24psi, I have had the chip bypassed and know the car peaks at 14psi which is what my car should boost.....not as much fun, but the engine might last a bit longer!!

Dom.

series_mcrae022

Thanks for the help everybody. Just looked under the footplate and there is a small black box joined onto some of the ecu wires. I have taken some pictures and can email them to anyone if you could have a look, im not sure how to use the pic uploader. If this is a fuel cut remover, how would the boost be raised?
Thanks, Roy.

Scott.T

iTrader: (2)

If it's a so called 'Superchip' there should be a bleed valve under then bonnet connected between the Actuator and Turbo Outlet nipple. It's probably hidden under the intake pipework.

Or the actuator rod has been shortened and the device is a fuel cut lifter.

Both connect to the map sensor signal on Connector B43 Pin 4
(looking at ECU in footwell it's the 3rd wire up, as from memory position 1 is not used).

series_mcrae022

Just went out a long drive in the car, in 4th gear it seems to peak at 19psi, and 17psi in 2nd and 3rd. Is this really bad for the engine? Can the fueling keep up with that?

+Doc+

Personally I would not run my McRAE boosting that high. 14Max in my opinion.
Doc

care3

mines t pieced on the centre pipe of the 3



[Edited by care3 - 1/11/2003 4:03:59 PM]

bigsinky

having read a few posts on the subject and read the views of others it might not be beyond the realms of the imagination that the boost gauge in in fact inaccurate. some ppls i have heard say that their boost gauge over reads. it all comes down to what you pay for the gauge. if you pay £40 for a boost gauge then i feel that you shouldn't expect to get mega accurate readings. now if say you bought the like of an HKS at well over £100 and you got wild readings then i think a stewards enquiry would be in order.

the old addage you get what you pay for may be true in this case.

just my 2p worth.

cheers

big sinky

edited for mucho crappo spelling

[Edited by bigsinky - 1/11/2003 7:26:36 PM]