chewy8000

I've been going back and forth on adding MSDS headers when I put the heads back on. I really want to put the extra money towards upgrading the suspension and tires, but I can't stop thinking about the performance gain the headers will produce. Plus easy access to install them. I need all I can get with a 4.5 16v. Any suggestions?

checkmate1996

I have headers, but they are pain in the *** to work on when taking the engine in/out of the car. Also, can get in the way of doing minor work like clutches and stuff. Now, they do sounds great, and give the car a boost, but if I had to do it over again, I would serioulsly consider looking at an xpipe for dave at 928 specialists...use stock manifolds, etc..

chewy8000

I think mine would be a Y-pipe. I definately don't want to deal with taking the headers off to work on certain things. Both options are around the same price. Pro's and con's? Same performance gains?

Mrmerlin

the Y pipe is your best bet it makes about 20 to 25 more HP

Courtshark

Always start to make suspension and brake upgrades before making engine performance upgrades. It's a little different on a Porsche, as the handling is already fantastic. But remember that if you go faster, you need to be able to stop faster, too.

hacker-pschorr

Do a before / after dyno

mark kibort

I dont think you need to worry too much about brake upgrades, although a set of performance pads never hurts if you take it to the track occasionally. Ive raced with stock 79 brakes and 84 brakes as well. the 84 brakes are more than capable up to 350hp on a 928. the 79 brakes work, but you have to learn to operate within their limitations on the track. the suspension set up is certainly something to look at with any car, when starting to drive in a more spirited fashion. However, the stock 928 suspension is good enough to handle any of the hp performance gains you could expect with the mods you are thinking about
mk

John V

I have an '81 with the newer S4 factory exhaust manifolds. Most agree that these greatly improve flow over the cast manifolds and that headers are only marginally better. I also have a modified Y pipe, "free flowing" cat and Borla exhaust. I didn't find this mod to make a huge difference.. but it did help some. I didn't dyno my car before but after, the car dyno'd at 198 rwhp which would suggest perhaps a 10 HP bump. I doubt headers and Y pipe would do much better than that.

chewy8000

Would S4 factory manifolds be hard and expensive to obtain? I imagine they would bolt right on correct?

John V

If you do a search, there's a ton of info on them. You can usually find them fairly reasonable and while they don't just bolt up, I'm told they are much easier than headers to install.

hacker-pschorr

The S4 manifolds do NOT fit. You want the 85/86 manifolds. They are the same piece except the 85/86 units have the same two bolt flange as the 16V head.

I had to enlarge a few of the bolt holes - once this was complete they bolted right on my 81.

John V

Hacker is correct -it's the 85/86 manifolds you want.