Log Mani vs. Tubular Mani. for KA-T

[docrice]

Hey guys, i'm still deciding on my parts selection for my KA-T project. Right now i'm deciding on what manifold i want to use and need some opinions... The car i'm using this kit on is my s14, which is mainly for autox and mountain roads, etc... don't want super high hp (expect around 250-300 max, not really important), but i really value throttle response and minimal lag time. Expect to be using a t3 variant (possibly KKK K26 from porsche 944 turbo) or maybe a t25/t28, leaning toward t3 if i can find one to suit my needs. basically, i'm weighing pros and cons of log and equal length tubular manifolds for my application and wanted some input....here's what i've got so far:

LOG STYLE
Pros: cheap, easy to find, take up minimal space, can be configured per application (i.e. jgs unwelded mani, etc.), reduced spool time/lag of turbo

TUBULAR STYLE
Pros: higher performance capability, (may) move turbo lower (away from brake M/C, etc)

[sdtouge]

tubular will eventually crack on you...

[docrice]

That's kinda generalized, don't you think? Cheap tubular will crack, yes, but a quality manifold made from good materials with good welds should hold up about as well as a log manifold....i don't know, i asked so prove me wrong if you have some evidence of this...


I really have to stress for the integrity of this topic that i'm not trying for huge HP or anything here, 1/4 mile times, etc. are the least of my worries. I want useable power that is safe and reliable, without the need for a full rebuild (yet) and a ridiculous list of $10k worth of parts. This is a budget project for moderate power and sacrifices can be made to an extent, as long as it doesn't mean paying $900+ for a manifold.

[Mike Wazowski]

I've never heard of a Full-Race tubular manifold cracking.

[NZO]

If you arent going for numbers a log manifold should be ok. Just keep in mind that I believe a tubular manifold will allow for faster spool.

[96twofourty]

tubular will eventually crack on you...
a statement of ignorance...

[docrice]

If you arent going for numbers a log manifold should be ok. Just keep in mind that I believe a tubular manifold will allow for faster spool.

Definitely want to hear more about this....i've heard both spool faster from different people. Some say that the short runners/small volume of the log manifold help it spool faster, but other have told me that tubular manifolds spool faster because they have higher exhaust gas velocity. Both sound good to me theoretically, but i'd really like to hear some real world experience from you guys. Thanks for the responses so far.

Also, anyone have experience with coating their manifolds? most tubular manifolds seem to be either stainless or coated, so thats no big deal, but if i got a log manifold i considered going with a ceramic coating ( I'd much rather do that then try header wrap or something else cheap), any cons of doing this that i should consider? thanks again, keep the replys coming!

[Phlip]

tubular will eventually crack on you...
Tell us, oh great one about how every tubular manifold you have ever had cracked on you, include in this dissertation, if you will, the manufacturer, where you got it and the flaw that caused the failure, so that the lesser among us will not repeat this...

[infinitexsound]

log cheap works............ and upgrade later when im rich and loaded

[docrice]

i've heard of the cheap tubular ones cracking, and i think that's probably what he's referring to....the $100 ebay manifolds and SSAC ones are prone to cracking due to thin walls/poor welds/poor design or any other number of factors...

[Mike Wazowski]

When Master Enthalpy compared a Full-Race tubular to a Log style he obtained about 60rwhp with the Full-Race over the Log style on the same setup (well and MAP vs. MAF). The Log spooled slightly faster, but who gives a f, I'd rather have the 60rwhp.

Full-Race, all the way.

[turtl631]

When Master Enthalpy compared

:ghey: :wackit:

[NZO]

Hmm, well I guess the shorter runner length compensates for the poor flow design.

[sdtouge]

i have never dealt with the expensive quality tubular manifolds but the ebay specails will crack eventually.

[boosteds13]

i have never dealt with the expensive quality tubular manifolds but the ebay specails will crack eventually.

Funny, I have personally yet to see a cracked SSauto but saw my friends $900 JIC manifold crack in 3 places on his SR. So much for that theory. I believe the ssauto manifolds that are on the market now are a little better than the previous ones.

[sdtouge]

well the top mount ones were the ones that very consistenly cracked due to poor bracing. the newer version suppossedly have better bracing. a buddy of mine got the ss autochrome and just took it to a machine shop and had all the welds stregnthend

[96twofourty]

Or you could just add a flex pipe on the downpipe and prevent all cracking problems

[SR240DET]

i've heard of the cheap tubular ones cracking, and i think that's probably what he's referring to....the $100 ebay manifolds and SSAC ones are prone to cracking due to thin walls/poor welds/poor design or any other number of factors...


holy shit... this is all wrong... any manifold will crack if it doesnt have the proper.... bracing/ good condition motor mounts.. and a flex section on your down pipe will help..... iv seen $1000 rage manifolds crack due to the fact that he didnt put his exhaust to engine bracket on with worn out motor mounts...... and it crack at the welds...

ssac will not bust if you use the proper bracing and flex section on the DP..

my buddy is still using the first manifold 3 years now by ssac for his gt28r kat and has what i said above... daily drives... races at the drag strip regularly and autox monthly... get your facts straight buddy.....

[projex240]

I dont kknow what sources are being used, but the top mount manifold from SSA is the ONLY version released. It hasnt been redone. There have been no cracks reported that I know of. I have one, and it hasnt cracked on me. IM pretty hard on my car too. The top mount ssa is BY far the best bang for your buck. Its like 180 on ebay,a dn trust me when I say, its not the hunk of crap that every one thinks it is. Mine is hard core rigid, and VERY well welded. Has the bracing too.

Dnno, but before you buy yorus, check into the company. www.phatka-t.com is a great one, but uses a sweet bottom mount. Import autoperformance makes a good top mount too. Lastly, before they went south in customer service, boost designs makes a good one too.

Dont be worried about SSA. They only have a bad past, It seems as though now the new models are MUCH better.
-Josh

p.s.--cracking is 9 times out of ten due to the exhaust putting too much stress on the mani when it moves from bumps, hard braking, etc. Use a good exhaust to trans brace, and use a long flex pipe about 12 inches long. Youll be golden.