ChrisB

I was doing some searches on this earlier but search has been turned off

Car is an MY99 UK Turbo. Currently has a RAMAir filter (probably coming off at next service after reading about them duffing the MAF sensor) and a Bell & Colvill back box (so fairly standard).

Thinking of sticking on a de-cat Scorpian down pipe next.

First question - how long does it take to fit and remove the DP? Car is due it's first MOT come March and I'm wondering if I should wait until post MOT to swap the DPs.

Second, I've declared the back box to Privilege and my Insurance Cert. says "Exhaust Change - Performance Upgrade" and engine power is increased up to 10%. Would a DP take me past the 10% allowed (still running the OEM centre)?

Finally engine "safety". Do I need to worry about running lean with the DP in place? In the past I've struggled to tell the difference between UL and SUL, so stuck to UL. I am running my 3rd tank of Optimax now to get some MPG figures etc so is it wise to stick to SUL / Optimax with a de-cat DP in place?

I guess most of this has been answered before, but no search!

TIA,

Chris.

john banks

For insurance purposes I am on 10-20% increase with PPP, decat downpipe, induction and boost controller. You can just get away with 10% for PPP (237/215). Most cars with downpipes are not quicker than a PPP'd car. Certainly a DP and induction did not make the same difference again as PPP, but not far off. Look at dyno plots and you can see SOME unmodded cars at over 230bhp and SOME decatted cars on less than 230bhp, so I think you will be fine on up to 10% increase. I would run on SUL, but other than that I don't think you'll go lean if your car is healthy, but get a Lambda link or make you own AFR meter for £10 to check. You may pass your MOT with a healthy catted centre section.

ChrisB

Thanks for the info John.

A trip to TSL next week might well be in order!

M_D_B

Chris,
you'll probably be OK at 10%. I have a PPP, Magnex backbox and ITG filter, and I had a max of 233.5 BHP on John Noble Motorsport's rolling road last weekend. Having said that, I'm insured for upto 20% power increase, and if I'd been to an other well known rolling road, I'd probably be nearer that. I does appear to be a case of find a low reading rolling road for insurance info, and a high reading one for the pub .
Martin.

ScoobyJawa

Hey Chris, how are ya mate?

GET THE DOWNPIPE - WOW what a difference it makes

My MOT is due in April (first one) but I thought what the hell and fitted the DP anyway I think you'll be fine on your insurance for 10% increase, exhaust. Mine was RR'd at 233bhp standard back in april (just before our little Alton Towers excursion ) and I reckon I'm on 250/255 now, in comparison to others in my area with the same mods etc and speed, so thats around 10%.

GO FOR IT DUDE

NBW

Chris,

I've been asking myself the same questions. I to have +10% cap on my insurance.

I averaged all the 99/00 unmodded dyno readings - it came to 235bhp! But as pointed out there are cars on there with full de-cat exhausts knocking out around 240bhp. I guess it all depends what fuel and the weather on the day of the run.

I wander what the insurers will charge to go to +20% ?

I'm also reliably informed that most cars with a centre cat will pass the MOT. They will probably fail the idle emissions test, but apparently the tester then does a fast idle test @2500rppm, and which it should then pass, particularly if the cat is nice and hot.

Cheers
Tim

[Edited by NBW - 12/16/2001 8:40:10 AM]

TonyBurns

iTrader: (3)

Im after a down pipe next hopefully trying to break the 270bhp figure for my MY00 PPP (pushing 249bhp at the mo) so having a full decat system should bump up my torque and BHP a touch
I think the hardest part will be to see which is the best d/p to get, either a twin or single, the choices are huge (i fancy a scoobymania one as i dont think many ppl have them so i want to be different ) and it should keep me withing the 20% bracket too (so no extra to pay on the insurance!)

Tony

ChrisB

Excellent - many thanks for the info guys.

What RR did your figures come from Neil?

I'm thinking a quick wizz over to TSL this week and dive into Nottingham for extra Christmas shopping

PS. Neil, I still haven't washed the car

[Edited by ChrisB - 12/16/2001 5:59:12 PM]

ChrisB

Next question - is a P1 standard zorst the same as a UK?

WagonFly

Check out the Revolution Motorsport downpipe(Gateshead - Ad in back of EVO mag). I had one fitted and it transforms the car. Lots of pull at low revs and strong 'go' right through the range. Much better at hauling you from 60 to 80 on the motorway too.

Was a bit concerned at the change in the sound of the Turbo (sounds like a truck!) and thought it may be stressing the turbo but done 15K mls with regular hard sprints and no probs yet. (apparently it feeds air back into the turbo or something!!)

When the baffles collapsed in the back box I got the full system and it is impressive.

I am not keen on spec sheets as I think a good A to B run on an A road is a better test. With the way it hauls out of a roundabout now I don't care about spec sheets!

One final thing. Put it through an MOT and no-one batted an eyelid. Don't think many check the cat scenario. Anyone been failed for this?
Anyone done any comparisons on this pipe with others? Preferably in driveabilty rather than a print out?

ScoobyJawa

Chris,

Must look like a proper rally car now

P1 isn't the same as a UK AFAIK, the BB is definately different not sure about the other parts........

Mine was RR'd at Power Engineering. I know some people don't rate their rollers but the same day we had an S3 on them too and that put out exactly what it was supposed to, and Audi's are renouned for producing what their supposed to.........so you can draw your own conclusions I think their rollers are pretty accurate myself.
Scott Ws was done there too (both the following figures are from runs on the same day)and came out at something like 244 with a SS centre and BB and then 255 with the SS DP too.

NBW

Scoobyjawa,

Pete C. quoted me 255-260bhp for a full SS system plus ITG filter on MY00, spot on your RR figure!

Am just going to go for DP though, and keep my WR Sport BB, as mine's a wagon and I don't want it too noisy.

Cheers
Tim

Markus

My downpipe is going on tomorrow, at which point I should be catless (still got a dog though ). Insurance company said there would be no additional premium increase, but that's because policy is already loaded due to other mods on the car, so that's not too bad.

as for fuel, well, I used to run on 95 RON, much to the shaken heads of most people (car is a jap import) but have been running on optimax for past few weeks, mainly to get myself into doing so for the arrival of the DP, as with no cats in the system, thus more free flowing system, i t could run lean, thus possibly causing det, which is a 'Very Bad Thing', so I'm not taking chances (anymore )

as for doing it, well, I've been told by many 'DO IT, DO IT!' and so I am doing it and will hopefully be able to add to the cacophony of voices yelling 'DO IT, DO IT!' by wednesday morning so, go on, do it! if you retain the original downpipe then if you don't like it then you can switch back and then sell on the DP.