Series 1 & 2 exhasut manifold

[AlpineRaven]

Today I've removed 2 engines from Series 1 and 2 Commodores.

I've noticed the difference between Series 1 & 2 engines, exhaust manifold are both different.

For power & fuel reasons which exhaust manifold is better and recommended?

Cheers
AP

[1991_Vn2nV]

VN series 1 and VN series 1.5 commodores were fitted with a rougher manifold than the series 2 engines. They were made from mild steel non-cast thin collection exhaust manifolds and were considerably noisier than the thicker, cast-iron non-collection manifolds that were fitted to the VN series 2 engines as well as the VP and VR manifolds.

As the series 1 VN's had the thin collection manifolds, there performance would be slightly higher, although it would be minimal. Fuel consumption wouldnt be noticeable. The series 2 manifold is obviously better made and quieter as it is thicker material.

[RVN 355]

VN series 1 and VN series 1.5 commodores were fitted with a rougher manifold than the series 2 engines. They were made from mild steel non-cast thin collection exhaust manifolds and were considerably noisier than the thicker, cast-iron non-collection manifolds that were fitted to the VN series 2 engines as well as the VP and VR manifolds.

As the series 1 VN's had the thin collection manifolds, there performance would be slightly higher, although it would be minimal. Fuel consumption wouldnt be noticeable. The series 2 manifold is obviously better made and quieter as it is thicker material.

vn- vr manifolds tend to crack so there both crap....

[hakhawk]

vn series one are better for performanc, doubtfully noticeable in kw, but dad recently fitted s1 manifolds to his vr, it has better takeoff, on both petrol and gas, gas used to be a slug, now it is actually decent. and cruising at 110 dropped from 2200rpm to 1900rpm. not sure why, but it did. fuel usage we havent really looked at. they say that the s1 cracked alot, thats why they changed to the cast, but dad being a mechanic has never actually seen a s1 crack, but has seen many s2 crack, including his own.

this isnt the be all of end all proof that the s1 are better, but in my experience, they have helped.

[1991_Vn2nV]

well the fact that the Series 2 manifold is thicker and is cast-iron. So all logic says they would be stronger and more reliable. However the series 1 had the thin collection manifold which really is what you get on an aftermarket extractor but the primary runner is so short its not really worth it, but thats where you would get a gain from. So its almost a cross between a stock S2 manifold and the cheapest set of extractors u culd find.

The S2 or VP Update engine is slightly more powerful (127kw instead of 125kw and a gain of 2NM of torque also) because of other changes to the cam etc., so thats why the S1 engine is not more powerful despite the exhaust manifold.