Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: Ro75Guan on January 05, 2012, 11:26:49 PM

Title: Customizing 75 TS 2L exhaust
Post by: Ro75Guan on January 05, 2012, 11:26:49 PM
Hi there,

Just would like to know if I'm going to encounter any problems in changing my exhaust and
what's the best way of dealing with it in terms of removing the catalic converter and the oxygen
pressure sensor. Only doing so to prevent it from sitting too low as you all know and also for
performance purposes but also I've already had to fabricate a new manifold due to a speed hump
that completely destroyed the old cast iron one. If anyone has already done this I would love to
know the best solution it would be greatly appreciated.

Cheers
Ro
Title: Re: Customizing 75 TS 2L exhaust
Post by: Domenic on January 07, 2012, 08:55:32 AM

Hey Ro,

You may want to try and message David Sammartino on these forums, he had modified his exhaust on his 75 twin spark to get better ground clearance. He may be able to give you some ideas


Cheers
Domenic
Title: Re: Customizing 75 TS 2L exhaust
Post by: MD on January 07, 2012, 09:57:44 AM
If this is a road car, it is possible to install small an efficient cat. that will do the job and tuck  up neatly so it is no lower than the section under transaxle crossmember.

The key point here is that your ECU requires the oxygen sensor to optimise your engine performance and it should be be retained. The second thing is, a vehicle that is originally fitted with a cat. is legally required to retain one and there are some very stiff penalties for removing them. Think this over carefully.
Title: Re: Customizing 75 TS 2L exhaust
Post by: BradGTV on January 07, 2012, 04:51:51 PM
MD, regarding cats, when i put a ts into my gtv would i need to keep the cat? or not if the gtv does not come with one from factory?
cheers, Brad
Title: Re: Customizing 75 TS 2L exhaust
Post by: MD on January 07, 2012, 08:03:14 PM
Brad, I am asuming this is for your road car.
I may be wrong but I think it goes on the basis of the car as opposed to the engine. Strickly speaking, any engine which is a replacement for the one that was in it would need to meet the same minimum air pollution requirements that the original configuration had.

Fitting a catalytic converter is the responsible environmental thing to do as the fuels presently supplied have some nasty chemical outcomes which would otherwise be simply burned and negated by the cat once up to temp. If you did install one,it would simplify the blue platting exercise in my opinion.

Having said that, I am not that naive to think that there are not a sheitload of older cars using new fuels without cats and yes, that certainlly is a can of worms that no-one in politics wants to touch with a barge pole.
Title: Re: Customizing 75 TS 2L exhaust
Post by: Ro75Guan on January 08, 2012, 11:40:15 AM
Cheers Domenic will do..
Title: Re: Customizing 75 TS 2L exhaust
Post by: Cool Jesus on January 08, 2012, 05:56:29 PM
Brad, MD is correct with the compliance aspect of the vehicles. Compliance is related to the year of manufacture, so check your complaince plate and refer to the ADR's as to emissions compliance for that vehicle. As you have assumed, if it came with no cat then one isn't required... as long as emissions are within compliance for your cars MY.

As a general remark, don't be too afraid of the retsrictions of cats these days, the market is now producing high flow units with very little effect on exhaust flow, especially when you consider that a daily driver is restricted by road speed, traffic calming devices, cameras, boys in blue, etc....
Title: Re: Customizing 75 TS 2L exhaust
Post by: DaveB on February 20, 2012, 11:02:09 AM
In my experience, the problem with aftermarket 75 exhausts catching is caused by lowering the car too much, & replacing the factory dual inlet/outlet muffler with dual inlet / single outlet.

That immediately loses heaps of  clearance at the lowest section under the car, the crossmember at the front of the transaxle .

IIRC, Dual factory small pipes are 1 1/4" side by side 
A single fat pipe (say 2 1/2 " exhaust) hangs down that critical extra 1 1/4" & catches

Of course, if the front is too low, the front pipes catch & handling goes off too unless the Pace adaptors are fitted.
Then there are non alfisti who drive without thinking about clearance ...
Title: Re: Customizing 75 TS 2L exhaust
Post by: shiny_car on February 20, 2012, 04:40:24 PM
Quote from: DaveB on February 20, 2012, 11:02:09 AM
Then there are non alfisti who drive without thinking about clearance ...

Err, don't quite understand your comment.  ::) I'm not an Alfista?  :P
Title: Re: Customizing 75 TS 2L exhaust
Post by: DaveB on February 28, 2012, 03:47:20 PM
Sorry shiney, pls dont take offense ...
Not referring to you, but others who don't / can't appreciate machinery, don't drive sympathetically & see alfas as another appliance.

There are lots of them out there, and few have alfas, by one means or another.