taffy993

Hello there, I've been debating for a while now on whether to go for the rsr's or the 2" bypass(LPMM), i finally made my mind up to go for the 2" bypass so today i took my car down to a local exhaust fabricaters near me and told them what i wanted, i was then told by the fitters that by putting a bypass pipe between the backbox, that it would interupt the flow of exhaust gasses which in turn would cause a loss in power. I'm not sure whether this is right or not, or whether they are just trying to sell me one of thier own fabricated systems.
I just want to know what you all think?
cheers
Lee.

MarkD

Exhaust will take the shortest/least resistant route it can. Under higher pressure it will push more through the bypass pipe... which also makes it sound better
Any effect, positive or negative would be immeasurable and utterly inconsequential.

Why would giving exhaust another route cause a performance decrease?
I mean, technically, I understand what they are gettign at... ideally, the route to the tailpipe should be smooth and uninterrupted but in this application... comon. lol

By the way, do they know that there is actually a bypass pipe inside the muffler?
Smaller tube, but it is just inside the can where the pipes go in/out.

jimbo3

There is already a bypass pipe inside the can. All an LPMM does is add a little more bypass, which is essentially what the "Motorsound" muffler does. I recall someone doing a dyno on an LPMM and there was no difference in power between it and stock, as one would expect.

Not sure what you mean by "putting a bypass pipe between the backbox", though. How much experience does you local exhaust fab shop have with 993's?

taffy993

Sorry what i ment was a bypass between the inlet and outlet pipe's to the backbox, the local exhaust fab shop said they had only worked on a few 993's and that they could make a new exhaust using shorter box's, i think they were just seeing pound signs, maybe i'll go some where else and go ahead with the bypass pipe.
cheers
Lee.

jimbo3

Is a "backbox" what y'all call a muffler? If so, I'm not sure what the heck the shop has in mind by shortening it as that would require A LOT of work to tear it open, modify virtually everthing inside, then weld it back together. In that case, you'd be way better off getting an RSR muffler.

taffy993

Ye what you call a muffler is known over here as a back box. The exhaust company is called longlife(uk) and they specialize in making stainless steel exhausts for all makes of cars from the manifold through to the backbox and they can make them sound how you want.(noisier or quieter). They were going to make new shorter and smaller backboxes to release more sound, price wise they want £400. for the two. Would be interesting to see what they sounded like compared to the RSR's/LPMM's.

GG33

I took a pair of RSR mufflers to Longlife (Wallington) a few weeks ago, they had themn for about three weeks before they decided that they couldn't actually do the job. They said they couldn'y cut the 2" holes. I have ended up taking them to a small fab shop in Church Crookham. Still waiting to see the results.

Meanwhile I am still loving my Supercups :-)

GG

Shaun Leahy

Taffy


MY LPMM story:

I eventually found Tino's Exhausts in Mitcham in SW London (in a small estate off Mill Green Road) as I thouhgt welding stainless to stainless was needed. Tino loves cars (especailly old Yank stuff from the 50's - 70's) & made my LPMM's and coated them (his idea). He specialises in exhausts and he is one of the few who can weld stainless (not actually necessary now I know) and in gearboxes. He deals only in cash. My LPMM was money well spent and cost approx £125 incl, welding, coating and fitting.

He claimed he could put a V8 in the back of the 993 but in no way could you call him a forecful salesman. Be careful of his mastiff, as the gentle giant slobbers over people, cars etc

I compared my 1 5/8" LPMM with an RSR elsewhere. No disrepsect to RSR's but my car has a deeper, throatier idle and more bass in its growl at higher revs. Each to their own, I'm .

taffy993

Hi guys, thanks for the replies and finally i've made my mind up, the car is booked in for tomorrow afternoon with longlife, just hope they don't say to me too that they can't cut the 2" hole, if they do i will have the number of you shaun for tino's exhaust's and i'll make the trip up there, I'll let you all know how it go's,
cheers
Lee.

taffy993

Finally the LPMM's are done and wow! what an awesome sound, I dropped the car in at lunch time and explained to exhaust fabricaters what i wanted done and they looked at me gone off, two hours later they were all crowded around and yes there were smiles all round, they all said they didn't expect them to sound as good as they do. Anyway I'm well pleased with them, now its on to the next mod, i think i've got the bug. Cheers All.

MarkD

Cool! Congratulations on the new sound!

1998C2S

I'm all in too. I just dropped my old mufflers off at the local fabricator for the LPMM upgrade. Perhaps I should say downgrade, cuz I am replacing supercups. I am going to try the LPMMs with the DACH X-pipe, cuz the SCs with X-pipe are just too much volume - glorious sounding at times, but not all the time. Should be on the ride next week, can't wait to hear the difference.