hopwood

OK guys since my last trip to the dyno with the 86.5 manifolds I have had a full custom exhaust system put on the car.

- 2.5" Y pipe
- 3" from the Y-pipe back
- 2 intermediate silencers
- flange before rear silencer to allow swapping of rear box for custom RMB
- rear silencer with 2 x 2.5" cores and 'staggered' tips for a look as close as possible to stock

Haven't been back to the dyno yet, but I tell you what, I've started her up and driven her home and

OH

MY

GOD

does this thing sound good. The perfect 928 sound: deep and slightly louder at idle, under 3750rpm at cruise it's literally only slightly noisier, but under load or above 4000rpm it's a fully resolved, ever so slightly dirty full on roar. I'll have to film it and put it on youtube, there's no way I can describe just how good this sounds....

More dyno results when I have them. And pics when I can figure out how to get them off my phone.

Joel

John Speake

:-)

Lizard928

Why 2" off the manifolds?

I always do 2.25 or 2.5.

Cheburator

I have to say that I baulked at the price when Joel first mentioned it to me. However, I can say that every penny of his hard earned has been well spent. The sound Joel's car makes now is simply incredible. Shame on you, Porsche, for not making them like that from the factory. I grabbed a ride in it last night and the beast is just perfect. I think it also pulls better from 3500 to 6000rpm. Of course there is only one way to tell and that is the dyno. Cannot wait!

Once again, well done Joel!

Ducman82

pictures?

VT928

I'm somewhat confused by your Y-pipe choice, since the 85/86 manifolds hace a 2.5 inch outlet why did you decide to step your pipe diameter down after the manifold flange, The restriction in any exhaust system is defined by the point of the lowest flow. No matter how open the flow is (3") aft of the Y it will be determined by the flow rate of the 2" piping used for the arms of the Y. IIRC the stock cast manifolds have a 2.25" outlet diameter. I would be interested to know what you hp and Tq numbers are compared to prior. Some insist that that a smaller pipe will increase tq

Paul

1980 Euro S Red/Blk Lea

hopwood

My bad - the Y-Pipe is the same diameter as the manifold outlet. Just trying to get the pics sorted now.

Mongo

Those Y-Pipes feeding in look like 2.25" ones to me and not 2", unless my eye-calibration is wrong.

hopwood

I asked them to do whatever matched the manifolds, couldn't see the point in not having the same diameter. I'm driving the car again tomorrow, decent trip, can't wait..

Joel

Mongo

I used to want a single 3" pipe on the S4 but heard they may be too restrictive on the 32v, so I opted for a dual 2.5" & X-pipe. Every single 16v car I have heard with a single 3" exhaust has this incredibly unique shriek to it. It almost reminds me of a cross between a Shelby GT350 and a Ferrari 355.

Tom. M

Louie did a test of the OttX pipe and custom 2.5 inch dual system vs. Tom Cloutier's Y pipe into a single 3" exhaust back...
Conclusion was that both performed pretty much the same and the weight advantage went to the single...

123quattro

More than one person has thought my car has a 180* crank in it.
84S dyno pull

cold_beer839

Nice looking system, I bet it does sound good.