High Flow exhaust - regrets

[Torquelover]

Help is urgently needed

 

Recently installed a high flow muffler to my Xsara. The result was not to my expectations.

 

Low end torque almost gone. Previously my Xsara was pretty responsive at low rev as peak torque arrived at 3000rpm. After the installation, can see the rpm needle taking its own sweet time to climb the rev range. Only after ard 4K rpm do I see an surge in the rate of increase (putting a smile back into my face). But anyway, conti cars are not high revving machines and the SG driving conditions seldom need me to rev beyond 3K on normal days. Even my wife can feel the diff (she though I was saving fuel after the recent price hike .

 

Any ideas (short of swapping back my stock muffler, luckily kaisu and ask to keep it) of improving the situation. Have not change the cat yet though (waiting for so good stuff to come in from overseas [angelic]

 

TL

[Mondeo]

Have U change yr filter to high flow as well? what muffler that U changed?

[Torquelover]

Should have gone for the Remus but instead choose a high flow muffler by 'Super Dynamics' (S$ 150) on recommendation by the mechanic. He said a lot of his customers using the setup and has no bad experiences.

[Mondeo]

What car U driving? Changed high flow air fliter?

[Mondeo]

Soly, my word is bad, I mean is't 1.6 or 2.0l.

But High flow muffle usuall on grant power on high end.

[Torquelover]

I am driving the Cit Xsara 1.6 (A). Anyway, the mechanic did claimed that the high end will be improve (which I have experience). But he mentioned that the installation will have cause me to loss my low end torque (which to bad is not true at all)

 

TL

[Sky8807]

If you rarely goes beyond 3500 rpm, u should not embarked on the high flow muffler. In fact all standard exhaust are efficient enough for flow up to that rpm.

You can improve by adding this and that but my suggestion if you find the mod does not meet your requirement, don't continue making more error and ended with more $$ spent.

 

You want more oomph every now and then just add those octane booster and you car will response faster and more power or those simple replacement like sparkplugs, fuel /oil additives and the likes.

Edited March 16, 2002 by Sky8807

[Mondeo]

Any other mod done on yr babe? My pervious Renault needed to mod others to suit the muffle. ie plugs & lead set, cone filter.

[Torquelover]

Will removing the cat or replacing it improve the situation?

 

Actually, my long term mod plans (do it one bit at a time to experience the effects of the mod)

 

1. improve the intake. I have installed a drop in K&N filter (good results). Did not went for the cone type becoz it will be a major engineering exercise to feed cool air to the cone.

 

2. improve the exhaust. High flow muffler + cat. (At this stage now. Negative results from muffler experiment - though my mid-high end has been improved)

 

3. Reduce the under bonnet temperature.

 

4. Improve the ECU.

 

5. Maybe changing the cams to fast road types (less than 270 degree)

 

TL

[Sky8807]

Removing the cat may give you a bit more hp but not sure about torque improvement.

 

K&N filter is superior to standard type for those who really need the engine to breath and best suited for the high rev type of driving.

 

Improve the exhaust flow will improve performance but first, must ensure that the engine is capable to push out that extra and the standard exhaust is actually restricting the flow then the result can be seen clearly.

 

When you drive aggresively, don't expect the bonnet temp to reduce. the temp will increase with high rpm driving, heat is energy and power.

 

Improve the ECu seem like a logical choice, the ECU is the nerve centre for engine control.

 

Fast road cams are good for high rev and u may have rough idling for the mod. Fast cams have to be complimented with fast flow exhaust system to benefit.

 

Of course, u need to re-adjust valve tappets and timings and all those related component so that they compliment eash other. A single exhaust will not give you satisfaction, a well done and good mod don't come cheap anyway.

Edited March 16, 2002 by Sky8807

[Torquelover]

Sky,

 

Thanks for your advice. Guess it will save me lots of my hard earned $$$

 

IMHO, in our pursue of motoring nirvana (short of purchasing a Ferrari), it always fun to try out diff mods, some may work while others will fail miserably.

 

BTW, can share your experiences and your mods you have tried so far?

 

TL

[Sky8807]

Now, I'm more settled and do not embarked in mods but maybe add on just to try for curiousity sake.

 

I have tried some cams, filters, valve and carburettor jetting and extractor changed b4 and there was improvement. Becos I do not want to spent lots of $$ and at the same time do not want my car to be way off from its original look and configuration so did not go for the real things. Though there are improvements but nothing compared to the real professional guys who do racing and mods.

 

For me, only kacang puteh, small times and hobby only so can't quote any good experience.

[Turbobrick]

Firstly, did U increase the overall pipe diameter? Plugging a high flow muffler but retaining the stock pipe diameter will be more balanced in terms of imporving high end but not sacrificing too much low end.

[Pauly75ts]

Hi! there, Torquelover,

 

Seems like you've done a negative mod by removing the restricted exhaust end. As you haven't done any improvement in the intake, it will cause a loss of pressure during the exhaust stage.

 

Was the i.d. for the exhaust line increased? I'd wanted to improve my intake by installing a Turbozet, but then there's a restriction in space, so didn't use it, unless I modify the intake to use cone filter.

 

 

When I first got my car, I'd wanted to do mods to the cyl. head, exhaust, suspension, LSD, etc., but in the end, didn't as the car performs very well in standard form. Now, it's only Koni sports shocks & ECU.

 

Now that my car is 10 years old, it's soon time to o/haul the engine, I'd get another cyl head and do some polishing of the intake & exhaust ports to improve flow a bit.

 

Rgds

 

Paul Yong

[Torquelover]

Nope, retained the standard piping of 2" all round.

 

Anyway, I guess it is a lesson learned to all who harbors plans to swap the muffler

[Turbobrick]

Well, retaining the standard diameter is the first of many key points to note when modding exhaust of a lightly tuned car. Going big on everything not always the best!

[Pauly75ts]

Hi! there, TB,

 

That's why, when the big mods are installed, there'll be plenty of big waste of money with big regrets later.

 

Many people will not be able to realise the full potential of their stock cars, let alone when mods are installed. That's why after driving my 75 for the past 4 years, it's time to put back the suspension kit that came with it, as my brother is selling away his Alfetta GT 1.8 soon, so we'll swap it back to my car.

 

Rgds

 

Paul Yong

[Turbobrick]

Yeah I guess there's too much "enthusiasm" when we first start modding cars that we overlook the smallest details and plug into the "bigger" stuff which can be detrimental rather than advantages.