Sebring Exhaust

cubist · Post by **cubist** » Mon Aug 21, 2006 1:32 am

How did you check there was no lose of power with the exhaust alone?

Bit confused... thrashed the car with it's std exhaust then parked it, let it cool, bolted up the sebring and thrashed it again. No loss of power. Easy.

Did you rolling road the car after the exhaust was fitted?

No. Did lose it easier on roundabouts in the wet at peak revs though that could be thin tyres and my special driving flip-flops of course...

What was the bore of the stainless J pipe?

Mine are one and seven eigths.

Don't 356' have a 'J' tube anyway with a flapper box arrangement (not heat exchangers)

Junk the stock tubes and 'h/exs' and save nearly 4lbs. Wear flip-flops instead of DMs and lose another 10ozs...

Sorry to be probing but I would like fact on if the exhaust is any good on performance.

Always happy to be probed... mine sounds xlnt, annoys my pedantic arsey twot of a neighbour and looks the very best

It's funny how all the serious players and racers don't use them ie:- P.R.Services,Andy Prill,Barry Curtis ETC.

Porsche did...

The G man · Post by **The G man** » Mon Aug 21, 2006 6:28 pm

Ahhh sorry the tenacious G man strikes again

Ok we have established that they are for looks only
Annoying neighbours and normal people would win it one point.

Porsche did use them but only on Carrera's
I belive that Richie copied the exhaust from Mike Smith's Gt when it first arrived fron Argentina in the late eighties and had Hayward and Scott make them for pushrod engines.

Post by **Bootsy** » Mon Aug 21, 2006 6:31 pm

The G man wrote:had Hayward and Scott make them for pushrod engines.

I've always wondered who made them for KK and now I know - thanks.

The G man · Post by **The G man** » Mon Aug 21, 2006 7:49 pm

No worries.

If you ask enough questions (the truth is out there)

G

Burma-Shave · Post by **Burma-Shave** » Mon Aug 21, 2006 8:45 pm

What're these exhausts, chaps? feel a bit like the new sober guy at a party

Both are on 'proper' looking racers..

Sorry such a huge pic

Post by **Bootsy** » Mon Aug 21, 2006 8:49 pm

That first one looks like a home made affair with a Supertrapp on the end of it.

Burma-Shave · Post by **Burma-Shave** » Mon Aug 21, 2006 8:58 pm

Is the supertrapp a glasspack thingy? Sorry to hijack..

I'll try again with the second one, sensible size.. looks home made too, I guess..

Post by **Bootsy** » Mon Aug 21, 2006 9:03 pm

The second one looks like a four into one merged header affair - is it defoo a 356 engine in there? Then it's got some strange muffler on the end, actually, looks like a stinger affiar wih a bend in it (god I'm using all the tech talk!)

The G man · Post by **The G man** » Tue Aug 22, 2006 8:25 am

Matched length pipes and tapered before they merge as well for back pressure.

Much more like a system that might actually work!

turbo thomas · Post by **turbo thomas** » Tue Aug 22, 2006 11:10 pm

i had this system in my workshop for a while whilst i 'replicated' the rear muffler arrangement for davids and paul foremans 550's...

from memory the pipes from 2 + 4 are 1 5/8" and the j tubes are 1 1/2". not ideal for performance but the loss would be neglegabubble...
its only the same as fitting a 4 into 1 header to stock heat exchangers on a vw

had the chance to buy it from david, if you got it for anything near what i was going to pay you've most certainly got a bargain...

cheers

rich

Quick912 · Post by **Quick912** » Wed Aug 23, 2006 9:22 am

Hey like the exhaust - forget the comments of powerloss.

g-man - power loss !! 3bhp........

No one could honestly notice an increase or decrease of 3 bhp.
that sort of power differance could be made by anything - temperature of the rolling roads they proberbly tested it on.... which is the norm.
The first run on the rolling road is normally best as the room temp is cooler.

Mike Smith · Post by **Mike Smith** » Sun Sep 03, 2006 10:33 am

It is nice to see someone thinking about these things and not just `accepting`

The truth about ANY exhaust is that you do not know whether it works or not unless you back to back it on a rolling road (or Dyno) before and after fitting

In designing an exhaust system, one of the 1st decisions is - What rev. range do you want it to operate in

The reason that all the race boys use other systems is that they have found a system that works for them - i.e. it produces HP and works througout the required rev range
That does not mean that there isn`t something better - we have just not worked it out yet
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Perhaps the best example I can give you - is when we were playing with the Carrera GT on the rolling Road (A Sebring Style System))

We added 50mm to each of the Primary Pipes

RESULT - Absolutly no change to max HP BUT we gained 30 HP at 3000 rpm and 60 Ft Lbs of torque

These were readings taken on the Same Day on the same Rolling Road
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Of course it meant that the pipe now stuck out of the back of the car by about 12" - I cannot tell you how many times I smacked my ankles on that pipe and catapulted myself across the workshop

Mike at PR

Rustbucket · Post by **Rustbucket** » Sun Sep 03, 2006 11:16 am

My 912 engine runs a marmitte (Spelling!) ANSI exhaust- with four tail pipes (twinnned), and twin mufflers.....
Any good-?
And would it fit ok under the rear valance of my 356b?

Mike- havent forgotten I need to call you about the pedal boards !!

Mike Smith · Post by **Mike Smith** » Sun Sep 03, 2006 1:39 pm

Sorry guys, as I said before - without Rolling Road time there is no real way of telling

It may feel more responsive - the sound might be great but as to what it is `really` doing - only the Dyno Numbers and the Dyno Graph will tell you

Mike - PR

DDK - Die Deutschen Klassiker

Sebring Exhaust

Sebring Exhausts

ANSI exhaust- with four tail pipes (twinnned)