1mm I think

Is 38mm inside or outside diameter of pipe?

??? 38mm is what I think is recommended for 2.4 with a scara manifold, if you are talking a different manifold then the power you want to achieve and the length of the primary governs the optimum diameter. If you are talking a 2.0 car then you should NOT try to go for a manifold designed for a 2.4 as it will just make the car more laggy

Yes, I'm talking about 2.0. I'm manufacturing manifold on my own, so what is the best diameter in my case, 35mm? Inside or outside?

What power do you want to achieve? How long will your primaries be, and will they be equal length?

I'm looking around 350hp + nitro. Not sure about lenght, but they will be equal lenght. Can you advice something for lenght?

whatever you can get to fit. Ideally you should taper it down from the port size. I guess for that you probably need no more than 34mm ID I would guess. Really whoever is manufacturing it should be able to advise

Thanks, will post some pics, when is finished

You know if you run huge nitrous that you will need bigger primaries but also really need larger exhaust valves and ports to make the most of it.

What is huge 100+hp? I'm planing 50-75hp, I will go with 35mm for manifold pipes that should cover me. When I rebuilded my engine I forgot about exhaust valves, that could easily been done in that time, but I totally forgot:(

yeah should be ok for that

If you can wait a short time I'll have one of the ones I've been talking about :-) this is the design I will be producing, I think with this design the water rail might need to be made as part of the kit but not sure...

http://i97.photobucket.com/albums/l220/fcck2000/fiat%20coupe%2020vt/s1.jpg

Paul

If you use 38mm internal pipe then it will have the same circumference as the length of the port opening. I'm opting for 38mm external allowing for the primaries to be slightly smaller. My thoughts are the T2 flange is quite small so velocity onto the turbo rather than volume should give early hard spooling... Although I would expect if big (450+) BHP was required then the larger primaries would be better.

Just my thoughts
Paul

Now I'm totally confused:( I was thinking about going with 35mm inside diameter for pipes. Don't know yet about lenght, but I guess that is all pretty much similar as long as they are equal lenght. In case outside diameter is 38mm, how much is inside? What is the pipe tickness?

35mm internal dia would be fine the O/A depends on what thickness material you use, I use 3mm walls on my manifolds, this is possibly overkill but I don't want them to crack.
I know with N/A engines the length of primaries can be all important to get the power within certain rpm ranges but with a turbo engine things are different, so length of pipes is not so important, as long as you try to keep them all the same.
Paul

There have been quite a few comments on here about the heat affecting the wiring - surely the current wiring can be insultated? I know that think Automotive do heat reflective tubeing that you could run the wires through?

Would your manifolds be suitable for heat wrapping, or would this weaken them?

Thanks Paul,


I will manufacturer one during this week. I think 3mm for walls is too much. I will go probably go with 2mm. Does anyone has AutoCad drawing for exhaust manifold plate, so I can cut it on waterjet? I don't know if plate is right word:) to be more specific, I need part which mounts on head, without primaries of course. I have Autocad drawing for 5 bolt turbine outlet for Garrett GT2860r if anyone needs

Dam i only use Catia you got any drawings for that?

No:( Maybe there is some converter.

Hi,

I have it in AutoCAD LT2005 version.
Post your email and I will send it to you.

- Jari -

Jari,


you have PM

Thanks

Did you lot see this one that just sold:

http://www.nyssaracing.com/Coupe_images/20vtmanifold1.jpg
http://www.nyssaracing.com/Coupe_images/20vtmanifold2.jpg
http://www.nyssaracing.com/Coupe_images/20vtmanifold3.jpg

Funnily enough, I set the price to match this thread :-)

the speed at which it sold suggests if Paul can make this price, he'll sell his ones easily enough

Well that all depends on dyno results. I would like to see a before and after run before I buy one.

Hi Trevor,

out of interest what was the selling price? and does that manifold fit with the water rail in the standard place? also do you have a spare water rail from one of your old engines?

Cheers
Paul

Don't forget the standard manifolds crack and cost more than £375 to replace with another one that might crack!

Equal length tubular manifold will flow better than the standard manifold, so depending on your set up performance gains are almost a certainty regardless of dyno results.

Paul

New standard manifolds cost about £250

Yes, all these figures and the design make interesting reading.

Still very expensive when they crack..

where are the new manifolds at 250?According to eper,900 odd