i want your opinon to which exahaust manifold to run on my 3k (60thou over, big carby but standard, bp head etc.) where not alout to run extractors because of class rules. I'm currently running the twin from a 3k or 4k not to sure but we have a 5k mani which is a single outlet. running a 2inch with one mufffler , we just want to know whats your opinon on the best i had a search and i found out twin is more torgue and single is more hp? not sure how true that is tho thankyou.

ill mesure then and get to yas.

If you can only use factory manifolds from a K series engine, get a 5K twin exhaust manifold, they flow infinitely better than the stock into 1 setup.

 

You might have some luck using a 7K Manifold, they are twin factory.. but you may have to play with the ports ;)

7k bolt upto 3k head? also we can't touch the ports or anything with a die grinder :(

shit, if you can't port the heads, What *can* you do to these motors? hahah

haha its ment to try keep the class cheap, doesnt really work though. we can bore 60thou any head that bolts on same with manis but must be k series standard carbies and thats about it. sucks hey

No, it doesn't actually.

 

That's why they put the rules there in the first place, to stop people spending more money than the next person to try and go faster.

 

If you want to go faster, go up a couple of classes.

you have to spend money to be able to win and if we go up classes then we have to start all over again :l

Ok so your stuck with using stock exhaust manifolds, but can you modify the manifold ?

Can you wrap it with that high temp wrap stuff ?

If you can then see if you can bore the manifold out a little, its cast iron it'll take a bit punishment.

 

Do some googling on exhaust gas resonance or exhaust waves or whatever. Basically its where the exhaust gas will send a sound wave down the exhaust and at certain spots in the exhaust that wave will turn around and travel back to the cylinder and either kill the intake flow or help the intake flow. If you add "steps" into the exhaust you'll be able to tune the wave into helping the intake flow into the cylinder. Mind you this wave does effect the exhaust gas as well.

 

Another thing is what are the winners doing to help them ?

allright thanks will have a look at it. no one tells anyone anything which makes it hard

If you can only use factory manifolds from a K series engine, get a 5K twin exhaust manifold, they flow infinitely better than the stock into 1 setup.

 

You might have some luck using a 7K Manifold, they are twin factory.. but you may have to play with the ports ;)

 

7kc has same ports as a 4k. 7ke are bigger and bigger studs too