robt964

What is it that with the exception of the stock exhaust/heat exchanger setup a lot of other systems can be prone to the drone? Is it down to the materials or thickness of the materials used? The stock headers/exchangers certainly look quite solid, thick and hefty.

HiWind

Price please Chris

StanUK951

In addition to Robs question above I would like to know if changing the headers us worth it HP wise? On another thread someone said the 993 headers were the main difference between the 993's 272bhp and the 964's 250bhp, which I had also heard elsewhere. If so, I'm surprised more people are not moving to 993 headers for the 20hp gain...?

ALEX P

If you think of the convoluted route that a 964 exhaust has to take effectively doing a lap of the engine in comparison to the 993's then it becomes clearer. I doubt whether simply changing the heat exchangers to the 993's would give you an instant extra 20bhp but it would help.

I personally think that any changes to the induction and exhaust should be carried out along with a session on the rollers to check AFR readings etc.

The 993 h/e need to have the flanges modified on one side to fit the 964 engine. They need to be cut off, rotated and welded back on. It's a pretty common mod.

You cannot swap straight to a full 993 exhaust as there is not enough room to fit the silencers (on the RH side) but there are loads of aftermarket silencers that will do the job.

HTH.

See link below.

https://rennlist.com/forums/964-foru...the-964-a.html

TheSilverFox

I have this system and it is loud, it does drone between 2400-2900 RPM yet I think it sounds great. I am convinced that any lighter aftermaket exhaust will drone to some degree. I use the car as a weekend & track toy. Previous owner put it on and I have never considered another system. Might be a lot for a daily, but other than that I definitely recommend it.

crg53

My question is, why would anyone spend $2000 plus on an exhaust system that does not increase HP and is noisy and DRONES so loud at cruising speed that the car becomes very unpleasant to drive.

TheSilverFox

Depends on the definition of unpleasant....

I personally like a throaty exhaust. Cant comment on HP as I have no numbers to compare. What I do know is it is enough to keep keep the wife out of the car allowing me trouble free motoring.

964russ

Why do you think that there's less power?
From what I've read theres more power with a re-map.

Steve Weiner-Rennsport Systems

That's the same question I pose to my clients when discussing exhaust changes.

Noise perceptions however, are subjective and one man's tea is another man's poison. I only mention this when I know a system will drone in the car's cruising range.

As a rule, I strive toward making changes that increase performance across the whole RPM range, not just at, or near the top of the engine's rev range. This is really what improves acceleration & throttle response.

Jjm4life

So now I should skip the headers and their exhaust altogether? I was under the impression this was a surly popular exhaust.

HiWind

Don't forget you can also shed 20-30kgs at the rear ... Big 'hp' Win (iykwim)

JasonAndreas

Interestingly enough, the 964 can reach nearly identical HP levels as a non-varioram 993 using the stock exhaust and just a MAF and live-remap. Whether or not that translates into anything meaningful when running the cars (modified-vs.unmodified) next to one another is another story...

John@Fabspeed

PM Sent with pricing.

NineMeister

Well, let's just say that after testing more 964 & 993 engine combinations than I care to remember, I for one would not be rushing to fit a 993 exhaust system onto a 964. IMO the 993 exhaust is not responsible for the additional power of a 993, most of this comes from the superior ecu installation and larger fuel injectors.

Chris@Fabspeed

I'm not sure where all the comments come from about the system not increasing power. It is a lightweight, track oriented system (thus the name "RSR Header-Muffler Kit") that does increase power pretty substantially from stock. On a stock 964 we have seen 25whp gains with the header muffler kit. Can one make good power with other exhaust combinations? Sure.