[reposted] 1JZ exhaust picture?

[George]

Hi All!

Want badly some pictures taken from below of car with a 1JZ, or even better of some custom or factory exhaust systems for the engine.

Just need to figure out how the first pipe should look like (Y-pipe). I had to make one, it looks like this, think its length isn't optimal.
http://album.foto.ru:8080/photos/pr2/227114/1162840.jpg

Any chances someone would measure it?

[86-Sh*tter]

http://www.ninjapower.co.uk/images/product/66431.jpg
http://www.bicperformance.com/images...z_downpipe.JPG
if this helps drop some rep please

[George]

Thank you! It didn't help much but anyway this is something already.

I just can't figure out how this downpipe fits. My engine has 6->2 exhaust manifold, its output looks like a plate with 2 holes. On your picture there is 2 separate pipes. Are you sure they are for an 1jz-ge?

[Jin~Jah]

http://www.ninjapower.co.uk/images/product/66431.jpg
http://www.bicperformance.com/images...z_downpipe.JPG
if this helps drop some rep please

that 2nd image link doesn't look like its for a 1j at all, or at least certainly not a remotely stock one...




that's for a 5m, but on the factory manifold in the pic, is that roughly what you mean by the "plate with 2 holes" kinda thing?

[George]

The top assembly is exactly what I mean!

Also, the picture is very representative in case of my question. The corroded factory thing has 2 long separate pipes running after manifold, while on the stainless system the 2 pipes are Y-connected together right after exhaust manifold interface. That's exactly what I've made by now, but I think that tunes the exhaust to waaaay higher RPM that was supposed by the factory (since I'm not replacing factory manifold, I think it's better stay stock in that part, too).

Since I couldn't find any used or new high performance exhaust pipe for 1JZ, I don't know how it should look like, even what diameter is optimal, so I've made something temporary just to drive right now )

[madmont]

Mine came with factory headers with cats attached and the factory had 2 pipes coming from the cats which were maybe 600mm long and then merged. I had to remove the cats and I fitted two pipes approx 800mm long and 38mm od. It is good to have the pipes between the headers and the merge fairly long to improve low rpm torque. My factory headers looked like this

[George]

$%&*! Looks totally different from mine, yours is probably newer. But a valuable info, too (especially the lenghtes), thank you! Now I know the order of values, in particular that my exhaust isn't bad at all. Namely, single 54mm pipe would work fine after merging the two pipes (it will have the same inner section area that 2x38mm pipes have).
The only disappointing thing is some experience, my friend tune some 4-cyl 2.3l 136hp engines to say 180hp@7000 if turbo isn't desired, and among other things he runs an exhaust system that is 63-mm all the way thru. So I still wonder if 2x38mm is adequate for 1jz's 200hp.

[madmont]

The 200hp comes in at 6000rpm and most of my driving is between 1500 and 3000rpm even so you will not lose much at 6000rpm . The outlets from the original cats were 42mm inside dia do not know what the pipes were. Try to keep the velocity up in the pipes before the merge . As a rule shorter/bigger pipes = less low rpm torque. Longer/smaller pipes = better low rpm torque.

[George]

I would prefer both =) So the idea is to make bigger single pipe and longer pipes before the merge. I also drive below 3000rpm most of time, however some extra high-rpm torque would be nice, too. Anyway knowing some reference values is much better than guessing about them, whatever you do. Very useful info.