Terzo Kid

Oh no!! more questions on boost pressure

I have a MY98 Terzo with a Superchip / bleed valve fitted. Yes, I know what a lot of people think about Superchips on here, but I had it fitted over 2 years ago, before I knew about this bulletin board or other tuning options. If I had my time again I may have done things differently, however I have had no problems and have been pretty happy with this set up. Using the great Defi gauges I have fitted, I was hitting a peak boost of 1.2 Kg/cm2,( which converts to 1.18bar / 17.0psi) and holding 1.1 Kg/cm2 (1.08 bar / 15.6psi). I have always been happy with this level of boost

Yesterday I had a Magnex de-catted downpipe fitted, to complete the rest of my Magnex exhaust.It certainly makes a big difference to the car. The turbo hits maximum boost far quicker (a rough guess would be approximately twice as quick) and the car feels significantly more responsive. The noise has altered beautifully. It has a deeper, more throaty sound to it, you can hear the turbo spinning more and the waste gate chattering.
Sounds too good to be true for £150 (+ VAT)- there must be a problem.

There is. Took the car for a bit of a play on some of the country roads around Devon and on a main dual carriage way. Peak boost has gone up to 1.45 Kg/cm2 (1.42 bar / 20.6 psi) and holding about 1.35 Kg/cm2.

This sounds dangerously high to me, Nothing else was altered when the exhaust was fitted.

Can anyone shed any light on what might be going on?

Can you expect such a huge gain in boost from fitting a de-catted pipe?

Does anyone know which way to turn the screw on the bleed value to turn down the boost pressure? If I try and experiment I have a 50:50 chance of getting it right / wrong. I certainly wouldn't want to get it wrong and turn the boost up further, I think it is probably already on the edge- BIG BANG BIG MONEY


I'm not really a new user. I've got problems with my home PC and have had to use my work computer. Hence, I don't really have time to do a search myself. Sorry.

Please help

Cheers

Simon

dowser

Get hold of a standard backbox - it'll introduce enough restriction to tame things a bit.

You can then tweak the bleed valve with more *relative* safety. That's an awful lot of boost - can you hear things creaking?!

Richard

john banks

johnfelstead

I aint telling you in case you missunderstand what i type and the engine goes pop.

Just a thought.

why dont you call a superchips garage and either ask them or take it to them and get it reset.

I once set up a car with a bleed valve fitted. When i got to it, it should have been running 15psi boost, it had 30psi and was detting so bad you could hear it over the wind noise at 100MPH with the windows open.

I hate the things.

SimonJM

Just to confuse things I have now fixed my PC at home and therefore have changed identity.

John - thanks for the link. Great site Lee.

Richard - I still have my original backbox in the garage. but don't really want to fit it back on if there are other options.

Surely there is someone with a Superchip / bleed valve who can tell me which way to turn the screw so that I can reduce the boost. I want it back down to 17-18psi

Cheers

Simon (aka Terzo Kid)

Terzo Kid

Can't really blame you John.

I have tried contacting Superchips via phone and e-mail - waiting for a reply at the moment. Unfortunately, I'm a bit impatient as I don't like driving like some of the tourists you get down here.

I can't seem to find a Superchip dealer near where I am. Um!! - I wonder if their website has a list of dealers. I'm off to try.

Cheers

dowser

You could have refitted the backbox by now

SimonJM

Back on my home PC again.

Problem all sorted now - boost back to original settings by altering the bleed valve.

Somehow my impatience and problems just don't seem very important today after the shocking events in USA. What kind of animals could inflict such devastation on innocent individuals. I'm just lost for words.

Simon