reptileis

Couple topics here- but they tie together.

1) whats the HP and Torque ratings on a 78 4.5L 16V?

2) exhaust- Im thinking complete manderel bent Borla system- Should I run race downpipes or headers? what diameter should i buy? This paves the way for any future modifications i might make.
What are the realtime gains to be had from this alone?

John Veninger

77-79 - 5-man (US) 4.5L-16v M28/03 219hp 245tq
from <a href="http://www.928gt.com" target="_blank">www.928gt.com</a> site.

As for the headers. Look at the Devek Stage II for the biggest gain. MSDS ones are better than the stock manifolds, but not great.

reptileis

I heard that the early 928's had lessened HP claims than actual. Mine sure feels like more than a mere 219. Hard to not spin the wheels from a stand still. Maybe there's been some work done to her.?

Mike Schmidt

The early ones also had the lowest rear gearing of any of 928. They had a 2.75 gear. That could explain some of the wheel spin.

Fletcher

Level 2 headers (devek) and borla or devek exh which uses borla mufflers (your choice of 1or2 mufflers). Devek have been great people to me so far. That Susan is tall... Anyway side point; Dennis Barton at Borla told me they scrap any exhaust that doesn't increase power by 6% or more. Typical is 6-10% gain. That's pretty good. 928intl sells the borla for $475. The devek custom exhaust is $$ more. Happy hunting!

Normy

I can tell you..

-My Euro model S2 has a factory 310 hp, and is all over the place. I cannot keep the blue smoke from the rear wheels, despite the soft 275/40-17 rear rubber.

[that is, when I can get the injectors un-fouled!]

Before I bought it, I test drove an '84 USA model 5 speed and it was quick as well, though it didn't have the manic high rpm surge my S2 has. This one was rated at 234 hp.

As to headers...if thats all you do to it, then you'll not notice any increase. To increase your output you need to do the whole deal- headers, Borla exhaust [I have one; I highly recommend it, as it has the ideal balance of loudness and sound quality, along with stainless steel construction], and an improved intake. Add bigger valves, an extrude honed intake, and a K&N and you can make over 300 hp like I do. When I bought it, my car had 225 width rear tires, and when I downshifted to 4th and nailed it at 90 mph one day I found myself sideways-

*Its all or nothing dude...it depends on your wallet. I run 13 second quarters, and ran down a C5 corvette recently.

Early 928's respond well to large changes. If you just add headers...you're not going to see much.

Anyway, fly safe-

Normy!

Fletcher

Also forgot to mention the late model tubular manifolds SS are supposed to be a good alternative to headers (maybe less smog hassle) not sure if the devek's have carb # or 02 fitting.
In calif you would fail a visual insp I think without carb# or something with headers, sorry thinking outloud.

reptileis

Thanks for the resposes guys,

I was going to replace the entire system, not just the headers- thats why I asked for reccomended tube diameters for upgrade. I run a 2.5 inch stainless on my 4cyl VW, of course she also has flow improvements throughout. This is a custom system with a flowmaster- cost me 350.00 (thats DIRT cheap) from an Oregon tuning CO. Techtonics. Im going to see if they will consider doing my 928 custom.
(i may see about a group buy option here if anyones interested)


Are headers the only option here?

Normy

Reptileis-

I had a Scirocco once, and put that Techtonics exhaust on. Sounded great- cat back system. Any VW engine with the "JH" engine code has a HORRID exhaust manifold. For a while, I think Rapid Parts [are they still around?] sold early Jetta exhaust manifolds and twin tube down pipes to replace this, and the combo was good for 12 hp right there- a 14% improvement! Bump the timing ahead 5 degrees and you could make your 90 hp GTI suddenly develop 107 hp. I'm not an expert on the early 928 exhausts, but I doubt you can get the same level of increase on these cars.

NOW...if we could just get Eurpean Car to do a "project 928" series.....

Normy~

reptileis

Normy

Nice- Im in the process of building a 1981 "S" MK1 Scirocco now.
The car is getting a TT race downpipe, 2.5" stainless w/ Borla Flowmaster, attached to an ABA 2.0 liter 16V block with 83.5MM forged aluminum Ross racing pistons, Knifed and balanced crank, lightned flywheel, topped by a ported and polished 1.8L 16V head, w/HD springs Aggressive Schrick cams, adjustable external cam gear, 4 Throttlebody direct induction to the head managed by a complete SDS standalone Digital system. (there's more, but these are the main upgrades).

weighing a total of around 1800Lbs, the car should be comparable in acceleration to a sportbike (depending on gearing).

For an AutoX type race I'd take the rocco over the Porsche for it's increadible agility, but the Porsche would be my choice for higher speed stability and handling. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />