Thinking of possibly doing away with my cats. DP Motorsport have quoted me £70+vat each for cutom made testpipes. This also includes 'flanging' my cats so I can swap 'em over at MOT time. Could I also gut the precats and remain legal? (I have a '94 model).

On the subject of precats, I remember reading that the Z only has a precat on the left hand side as there is no room for one on the right & that pre 92 models have no precats at all. Is this true, or did I dream it up one night after a *couple* of beers?

Dave

 

 

BTW- Does anyone have a cat-less Z with a Mongoose exhaust?

It's not too loud is it?

Dave

 

Dave.

 

Before you do a thing ask Mark off the website about DP exhausts

 

Dave:

 

DONT DO IT! Well actually yeah do it, just NOT WITH DP!

 

My breif to them was...

3" Straight through with an X and finishing in two Apex Dunk boxes with 5" tips.

 

Their reply was "We'll give it a go!"

 

It cost me the best part of £1400 quid... this is what I got.

 

The boxes werent mounted properley, they packed out the hangers with wheel nuts so the tips didnt touch the body work!

 

They ruined my old exhaust and cut the flanges off it for the new one so I couldnt even go back to using that.

 

They then 'lost' my old exhaust (which was in mint condition) and have still not re-imbursed me for its value.

 

After 2 or 3 days on the car, most of the welding seams started to give! I got some rusty old cats and a HKS legal system and put that on as an emergency measure. Johnny (Grasshopper) took the exhaust to DP to get it repaired and they charged him £200 to repair their shoddy work.

 

I WOULDNT LET DP NEAR A DINKY CAR LET ALONE A REAL ONE.

 

A word of warning for people looking at Apex stuff (AVC-R & AFC etc...)

 

They havent got a clue what theyre doing with these either - speak to Bob instead.

 

Gonna sign off now before I start ranting on 'bout how incompetant DP are, but incase you didnt catch the drift DONT LET DP ANYWHERE NEAR YOUR Z - YOU WILL BE SORRY.

 

/\/\ark

 

 

 

Cheers for the info Mark, sorry to hear about all the hassles you had.

 

Oh yeah, There Prices are Wank too.

 

Here come the law suit ..LOL ...Not.

 

Z ya

 

Nico91TT

 

 

 

 

 

 

Couple of bits of info ...

 

1) Jap spec Zs don't have pre-cats. As far as I'm aware, UK ones have them both sides

 

2) I have Mongoose & no cats (standard cats have been gutted - cost about £170 which I now think is steep). Not too much noisier than without but I'm told that from behind the car sounds 10 times nicer !

 

Dave

 

Dave,

 

UK cars only have one precat fitted after 1992. Nissan couldn't fit the second one becuase of the steering column / turbo arrangement.

 

Dave W - Daves car sound very good with the cats removed and mongoose system. It's a great improvement over the quite stock setup.

 

Jez will also confirm that removing the cats benefits turbo spool up and I think he managed an extra 0.2bar boost from his

avc-r, without adjusting it.

 

This shows that the turbo's are under much less stress when producing boost.

 

Steve

 

 

 

Just a cautionary couple of notes

 

1- When getting the cats removed the "cheap" option is to cut the pipe before the cat and after the flange then weld in a straight section - don't let them do this, I did on mine and now I can't bolt up another cat back system (as I don't have the flanges anymore...doh!)

 

2- 3 out of 4 cars around the '90 model year I've seen that have the cats removed start puffing blue smoke almost instantaneously. The reduction in backpressure is great for improving turbo spool up, but also reduces the pressure on the turbine side of the turbo greatly increasing the chance of oil getting past the turbine seal and into your exhaust (and thus blue smoke).

 

Mine did this also, I started it up 10mins after having the cats removed and bingo - blue smoke. DOH!.

 

But DAMMMMMNNNN did it sound healthier, with my exhaust it takes on a really raspy exhaust note, kinda like a cross between a Porker and M3 :-) Sounds bloody awesome nailing the throttle in 2nd with the tops off :-)

 

Rowan

 

what's the cure for the oil seal problem ?

 

would newly rebuilt turbos soon start to do the same ?

 

should you specify stronger seals when getting them rebuilt ?

 

Or is it just due to the turbo/engine age when you get the cats removed ?

 

 

 

Silvia did mine. Mines a 91 so don't need cats. I had Elite fit two new Remus back boxes with twin chrome tips on both sides. Then Silvia did the centre section in large bore (60mm) stainless steel which means that the horsepower restricting washers are removed. Then they did the front section and got rid of the CATS. No problems whatsoever. Turbos spool up better, and I get appx 4 MPG extra.