quote:
Originally posted by Monaroman68
Woz my son is a fabricator by trade so its possible for him to make just need to no what style sizes and lenghts etc , was just looking for a quick fix here thinking someone my have a set of custom pipes to do the job. My engine guy suggested 4 into 1 with 34" primaries at 1"5/8 but i'm herein that that could be to small he also suggested a merge collector like the ones used in nascar usac etc any help would be very appreciated.
Cheers Dave
I would stay away from 4-1 items full stop. 4-2-1 items done correctly are the way to go in my opinion. There is a small gain in peak H/p using the 4-1, but the sacrifice in low-mid torque is fairly dramatic.
Because I don't know what went into the internals of your engine it is very hard to comment on what you need regarding length and diameter, this is something you would need to trial and error on your engine on a dyno.
There are formulas to calculate runner lengths and diameters, so thats probably a good place to start.
What I can say though is that I have found that being slightly on the small side can work better than being on the large side in alot of cases. And with a 4-2-1 it is very important to collect 1 and 4 together, and 2 and 3 together.
Making your own is time consuming, but if your son is a fabricator you could have a play around. If you're serious about it making the best power (which it sounds like you are) it is well worth the effort though, and done correctly they will last for years.
Woz