Decat

I am shortly getting a new exhaust system made with a decat pipe. Other than fitting a new Walbro fuel pump. Is there anything else that antone would advise doing?

Would i need a restrictor ring or would the boost controller do the same job?

Sorry if its a dumb question!!

You should have a boost gauge. You may need a restrictor. Uk or Jap?? Jap tend to over boost once the cats are out. Not sure if the boost controller would contol the level of boost as the wasgate on the jSPEC are too small so a restrictor ring may be needed

Or am I chattin rubbish

The car is a Jap Spec.

Am still new to these cars any advice would help.

You'll need to replace your plugs to a colder set to cope with the increased level of boost. Denso IK22's are the recommened ones. People have experienced detontation & misfire because of not upgrading the plugs. Talk to the Vortex boys

The Walbro as you've said.

Without the cats - you could boost spike to 1.4Bar - not good. You'll need a restrictor ring to bring the boost down to a safe 1.2Bar. See Chris Wilson or Paul E.

You'll also need a Fuel Cut Controller. Fuel cut occurs when the stock ECU detects boosts levels >= 1 Bar. TRL sell the - VFCC. Rather than removing this restriction - it increases it. So that Fuel Cut occurs at > 1.2Bar ... as I understand it the Fuel Cut limit is configurable.

For you're MOT - 2 decats might work better than a single decat pipe. With the 2 decat pipes you can just swap decat pipe #2 for cat #2 in about 20 minutes.

I'm guessing but a single decat pipe - would this be more of a pain in the arse ? I don't know, maybe someone else who's more brainy than me can answer this better.

Edit: As far as I understand a Boost controller can only raise the boost - not lower it. I guess you'd only need a boost controller - if you never reach 1.2Bar with Restrictor Ring in - set @ 1.2Bar in cold weather. So you'd use the Boost Controller to raise the Boost to 1.2Bar.

Smarty

I've got a J spec TT, it's fitted with a Nur Spec R exhaust and recently I did the full decat.

When I push the car hard on full boost I was getting a misfire so I was looking into getting some new plugs.

Thought about getting the Denso IK 22's at approx £65 - £70.

But after doing a search on here and the mkiv.com site I find they recommend NGK BKR7E (6097) , bought a full set of these at my Partco shop £10.47 including VAT.

The car is now running perfectly!

The Denso plugs may last longer but I'll change the NGK ones every 6k miles and still save a load of money!

Originally posted by merckx

NGK BKR7E (6097, bought a full set of these at my Partco shop £10.47 including VAT.

I thought the NGK BKR7E's don't come pre-gapped for high boost ?

All the feedback I got from Q&A here - has been either

a) Denso IK22's or 24's

b) NGK PFR7B 4853 laser platinum plugs - good for 1.4Bar

What Spark Plugs ?

Sorry, forgot to mention NGK BKR7E's need to be gapped to 0.80mm (32 thou). They came pre- gapped very close to this anyway.

On the mkiv.com site they recommend these plugs for the BPU upgrade and after doing a long search I found others on this site that also use them.

Got this from mkiv.com

Here is a list of the most commonly used spark plugs,

Stock Denso PK20R11, Comes pre-gaped at 0.043 inch (best on stock supra)

Stock NGK BKR6EP-11 (2978), Comes pre-gaped at 0.043 inch (best on stock supra)

NGK BKR7E (6097), Comes pre-gaped at 0.032 inch (best on BPU & APU supra)

NGK BCPR7ES (3330), Comes pre-gaped at 0.032 inch (best on BPU & APU supra)

ik22 is perfect for bpu change them every 10k max

ik22 is perfect for bpu change them every 10k max

This thread is 5 years old mate! Please check the last reply date before responding

This thread is 5 years old mate! Please check the last reply date before responding

Was just thinking when did i ask about a decat

Hell, your car has changed abit since then:d

 

Was just thinking when did i ask about a decat

I did at first wonder why you were asking about decats

And why am I subscribed to this thread?