de-cat

[Rob Moch]

hi all
after my post last week i'm going to get both cat recplacment pipes from c.w i note that you all say i need a T.R.L V.F.C.C is this some thing i can fit myself or do i need some one in the no to fit it for me, if i do need some one to fit it for me any suggestions ?

thanks for the help rob moch

[Justin]

You can do it yourself mate piece of p*ss. I did and I'm no car doctor.

There should be a colour coded wiring diagram on the TRL website. That's what I used and it worked fine.

J.

[Darren]

And if you decat and remove fuel cut....IMHO I would suggest a boost gauge...just in case though your car is a UK so is prob alright...anyone else confirm please...?

[AJI]

Rob, when I got my exhaust fully de-CATed with CW pipes I didn't have to do anything with my car. The restrictor on the cat replacement pipes keeps everything ok I was told and I haven't had any problems.

[Willson]

AJI, have you got a boost guage ?
You should hit fuel cut at about 14 psi, I belive.

[Brian Jackett]

Fit a boost gauge.

My old Supra which I de catted shortly before selling it bossted to 1.4 even with restrictor in.

In the end the turbos blew, I think a lot of cars are different.

And you cannot lower boost with a boost controller only raise it

[GavinL]

Originally posted by Darren
And if you decat and remove fuel cut....IMHO I would suggest a boost gauge...just in case though your car is a UK so is prob alright...anyone else confirm please...?


UK spec cars do not overboost

[AJI]

Gwilson : No I don't have a boost gage as GavinL says the UK-specs don't boost creep into danger levels.

[Andrew]

Very easy to fit Rob, a boost gauge is even easier .

The TRL VFCC is great because it can be set to 18/19 psi by Pete, so you get a raised fuel cut.

I would suggest a BLITZ Dual Turbo Timer too, as this has an electronic boost gauge, with peak boost readings and an audio/visual alarm, I have mine set at stock fuel cut around 14psi so I know when I'm pussing it. Again the BLITZ DTT is very easy to fit.

[Willson]

AJI, it just seems that you're not making that much boost if you're not even hitting fuel cut (without a defender). Maybe that's how you want it though.

[Martin F]

Originally posted by gwillson75
AJI, it just seems that you're not making that much boost if you're not even hitting fuel cut (without a defender). Maybe that's how you want it though.

It's because of the larger wastegate on the UK spec cars, as others are trying to say above 'UK cars will not overboost'.

If you wish to increase boost, even with a de-cat on a UK car, you need to use some other means, bleed valve, boost controller.

[Willson]

Right, sorry, I didn't realise the wastegate on a UK kept the boost so low. I thought it just kept it safe (18psi).
Thanks for correcting me.........:innocent:

[THOR Racing]

The TRL VFCC is great because it can be set to 18/19 psi by Pete,

Actually it can be adjusted by anyone (the user). It's set by default to be 18/19psi but if you don't like living that dangerously then you could set it to say 15.5, 16, 17 psi etc etc See graph on the site.

19psi is about the max as the MAP sensor maxes out at around 4.95V which is around 19psi.

You could fit a 3bar MAP sensor and scale the output for the ECU but use the extended range output with the VFCC to give you 22psi overboost protection (or again whatever you like). I've often thought about making something like this. i.e. replacement MAP sensors that allow greater range of VFCC control.
Thinking about it I'm sure I could use the existing MAP sensors used on the multitude of boost controllers out there.......just thinking out aloud.
So even the high boost guys would have fuel cut protection.

Regards
Pete

[Jez sutherland]

OK guys,

Bearing in mind all that has been said - especially about the UK specs:

I have a UK 6spd TT, which will be getting in nice new exhaust soon. I'm also seriously considering getting rid of the second cat (not the first one though).

What else will I need to do? Will I hit fuel cut? Will I need a VFCC? Will I need a boost controller to get anything other than stock boost (due to the bigger UK wastegate?).

I'm sure this discussion has already provided the answers to this - but could someone actually spell it out for me as I'm being very hard of thinking today!

Cheers,

Jeremy

[THOR Racing]

Simplest thing to do is WAIT!

Wait until you've fitted the exhaust and IF you hit fuel cut

1: You'll know you're at or above 15psi boost
2: You can fit a fuel cut defencer to remove this

If after looking at your boost guage you decide that say 16psi (*) isn't enough then fit an electronic boost controller.

NOTE: (*) that was a guess, sometimes the exhaust de-cat gives you 18psi other times it doesn't. Suck it and see as they say.

If it's too low you'll need a boost controller (Either manual bleeder valve or electronic)

This is the simplest and foolproof method. Saves wasting money unnecessarily all in one go.

Guaranteed you'll want it all by the time you get used to the extra power that the de-cat gives you.

No one can tell you 100% what will happen. De-catting is a little variable from car to car.

Regards
Pete

[Mid'lifecry'sis]

agreed.

I have just done this.

HKS air and HKS hyper full system leaving the first CAT in. I hit 1 to 1.1 bar and fuel cut kicks in then, 3 seconds and the cars back on track - but a pain.

Also going to change plugs - toyota to cooler ones.

My fear with Jap tubos is over boost. I have a greddy defencer - an early purchase when I knew less than I do now - which is nothing - yes a bad buy. £95 quid - any takers !?

If I fit this, can I set the defencer to say 1.2 bar and fuel cut there???

[THOR Racing]

If I fit this, can I set the defencer to say 1.2 bar and fuel cut there???

I'm assuming you're referring to the Greddy BCC device?

This device is not adjustable in that sense. It will illiminate the fuel cut that happens at 15psi and that's it. Any adjustment is for different cars.

If you were refering to the TRL VFCC then you can adjust to a MAX of 19psi (which is a limitation of the stock MAP sensor and not the VFCC)
OR
set it to any value from 15psi to 19psi. It's in about 0.5psi steps.

Regards
Pete

[Mid'lifecry'sis]

I want it - I want it - I want it - buy buy buy...

how much ?

Greddy for sale! Never used....:sly:

[Bobbeh]

Jez, I done think you'll have any problems at all if you are still leaving the first cat in place.

UK specs apparently handle the exhuast change better than the J-Specs. (someone who knows what they're talking about can take over from me now)