Outer Limits 4x4 Board

im gonna get the exhaust done on my sierra and was wondering what is the best way to go for low down power. should i go for extractors and a hi flow system or leave the manifold and just put a larger system on after the cat????


thanx jayson

Jmo , Just do after cat - You won;t get any nasty flat spots around idle to figure out ,

i was told if you have a longer second stage pipe it give good low down like if you exaust goes 4 in to 2 and then into 1 i was told if you make the 2 into 1 section longer it give good low down power but then again some of this tech on then net is a bit dodgy

gotta do exhaust now coz i broke it today having fun in a housing estate(dont ask) i snapped the weld b4 the cat and it sounds like crap and goes crap. is missing and have almost no back pressure. how much would a full system cost including a new high flow cat and extractors?

shouldnt cost heaps and heaps if u just replace the bit after the 2 into 1

dont worry about the hi flow cat just make a fake one. its illegal but like any cop is going to pull out a pollution meter. if you know someone you could polly get it all well under $500 including extractors. have a look on ebay for extractors but there are always sets floating around.

Tosh

I recently had extractors, new cat and exhaust fitted to my vehicle. Cost about $600.

I think it has made a big diff low down.

gonna tyr to get exhaust done over the xmas break. gonna go the extractoes and have a commy cat welded in place .

Bundyzook -

No cop is going to pull a pollution meter on you but the DOT guys sure will.
I got pinged (with a badly out of tune engine and carby - since reco'd) by them just 10 mins north of brissy on a busy as road.

Didn't cop a fine or defect note (thankfully) but they were targeting old cars - pulled up a Kingswood behind me.

I'm sure they'd know if you didn't have a cat in there!

Paul

Meow..

Did yours have a cat?

Mine does not as it is a 85', i think the cats came out in the WT's or late NT's.

cheers

Cat's in there - 90 WT.

Was overdue for a service and needed a tune - was about 15 times over the limit!

From memory catalitic converters became law round 86 or so. If a vehicle without a cat is put on a gas bench (emisions tester) the user will have no problem detecting it. If ya cat is in good working order you shouldnt be loosing massive power cause of it, especialy on low powered almost stock engines like the majority of 1.3L running round. I got 4-2-1 extractors, high flow V6 commadore cat and single straight through muffler (2 inch pipe) and it is a deffinate imporvement. Have run with a "bashed out" cat too and there isnt realy a difference on my car anyway.
Layto....

Well P_Bryne considering that until 90 they didn't even have Cat's in Sierra's i really dought they are gonna know if ya dont have one in considering its the same engine. I have a heap of mates that dont have cats i just helped a mate of myne put a fake in a series 4 RX7. They wont know even if they asked say that they didn't come out with one. Like they are gonna know anybetter! Also if your gonna worry about things as rare as being pulled over by DOT then take off any big tyres and any non engineered part on ya car. seriously you nearly have to leave your car dead stock if your gonna worry about those guys. I took my girlfriend into Main roads with the 31" muddies and un engineered bodylift so she could get her licence and there were guys checking vehicles down the side, didn't bat an eyelid at my car.

Tosh