Ad0911

I have read a lot of posts about headers. Most of the replies are abut 85/86 headers and using Y-pipes and other alterations to the exhaust system. The question I have is about my '78 4.5L with cast iron maanifolds. Are the 85/86 headers from an S4 and later? Is an improvement in hp or torque to be expected if I delete the old cast-iron manifolds and put the S4 manifolds/headers in place? Is it a straight bolt on or do I need to change the exhaust system on my EURO car?

Ramona

The 85/86 are an easy conversion. The S4 have to be slightly modified. I had intended to do the same conversion on my '82 many years ago but had trouble sourcing a set of 85/86 headers. I sent off my cast iron headers and had them ceramic coated, I was surprised how good they turned out. Still heavy of course but probably quieter than the SS units. Engine room temperature noticeably lower.

85euro928

I switched out the stock cast exhaust manifolds on my 85 ROW to the stock 85 SS units while I was changing out the motor mounts because I was in there anyway, needed a new cats (Federalization put a swedged USA version cat complete with baby grape weld), and I wanted to utilize an 'X' pipe for better flow. The mounting stud fit issues were minor and except for the fact that the SS manifolds utilize a staggered set-up which required the purchase of a small extension piece to make the 'X' pipe fit it was an easy install. I was told the manifolds would make more HP but less torque(?)but I can't confirm as the existing cat was seriously choking the flow to begin with. In a nutshell, if you have a ROW with cast manifolds and the forum agrees the later stock SS units will fit, go for it. However they won't be headers, just better exhaust manifolds.

Landseer

85 / 86 Stainless 32V pipes bolt-up. But a short extension is need to match downstream pipes, as noted above.

87 and after, I think, use a different bolt pattern to mount to engine and fitment is supposed to be possible but poor on earlier cars.


Another interesting approach is the MSDS "bundle of snakes" type true headers. I think they are still available on the market, plus sometimes are sold used.

joejoe

I just sold my '85/'86 msds header (new) for $300 at sharktoberfest. 85/86 is 2 bolt pattern, 87 later is 3.

SMTCapeCod

The MSDS are true headers, but I wouldn't call the the bundle of snakes.
The bundles are the low-production units that aim for equal length primaries.

IcemanG17

The 85-6 headers are a direct fit to the head, but do require some custom fitting to mate to the stock Y pipe-cat...however I do think there is a small HP gain.... On my automatic 928 Estate with a custom Y pipe (think cut the cat out and replace it with straight pipe) makes 203whp...not bad for an engine quoted at 234hp....

928mac

I am going to stay away from them due to the extra heat.

mark kibort

If anyone gets some level1 devek headers, I have the cat and pipe to fit a stock exhaust system for a pre S4 model.

GlenL

It'll boost air flow at higher RPMs so an increase in torque and HP.

I did this and they fit the engine correctly but don't match the pipes right. The left side is a touch too long, but it works as-is, and the right side is too short and needs a section of pipe welded in.

Don't expect miracles. Maybe 10HP for the swap. A more throaty sound, too.

One more thing: the left-side manifold, on my car, will touch the steering column U-joint, or bolt, on tight turns to the right. My mounts are new. I needed to change the orientation of the bolt to have the head facing the manifold on turns. Still will happen when making circles in a parking lot but doesn't on the track. Scary? You bet.

Lizard928

Glen,

I noted the same thing with the bolt on a customers car.

I clearanced the bolt some, and put in new motor mounts, problem solved.