Unique Autosports Rb25det Exhaust Manifold

[drgnball34]

Looking at upgrading my standard exhaust manifold. Not even going to bother with the ebay crap. Heard bad things and pretty dam cheap for quality id say. Pay for what you get!

Unique autosports offers one. Anyone have one? Would like to hear feedback on their quality and durability.

[Craved]

perhaps linking to the one you want, so there isnt any confusion

[R31Nismoid]

I doubt a reputable workshop like UAS would sell crap

[drgnball34]

http://www.uniqueautosports.com.au/priceli...tainlessman.jpg

MADE FROM 3MM THICK 321 PREMIUM GRADE STAINLESS STEEL.

[Lazy-Bastard]

Looks like the same crap you see on ebay.....definately not tuned length so what's the point. I wouldn't expect it to perform any better than the factory log.

[HRthirtyone]

do a tig welding course then borrow a tig and make it yourself then get it ceramic coated. if you do want to buy one, get one where the "pipes" from each cylinder to the merging point (where they all meet) are the same length.

[Roy]

For what its worth, my Greddy manifold is a 6-3-1 style manifold, Not equal length 6-1 and it works a treat. Though the airflow is still uniform and the collectors nicely done. I dont think the equal length is the end all be all ...is it ?

[R31Nismoid]

For what its worth, my Greddy manifold is a 6-3-1 style manifold, Not equal length 6-1 and it works a treat. Though the airflow is still uniform and the collectors nicely done. I dont think the equal length is the end all be all ...is it ?

IMO it isnt.

My GTS-R one wasnt equal length either.

Was good enough for Nismo, was good enough for me

Other guys - please dont just call something "garbage" without an iota of proof. Refer to the forum rules.

Posts removed

[Lazy-Bastard]

I'd like to see a direct comparison between the manifold in question, a factory manifold and a "name brand" AM log style. I reckon the performance difference between the 3 would be bugger all.

Edited November 16, 2006 by Lazy-Bastard

[khunjeng]

The basic theory behind manifold and exhaust pipe length tuning is based on organ pipe theory. A tuned length exhaust is literally that - a length at which the pipe has a natural frequency of resonance which matches the resonance of the engine at a particular engine speed.

Longer tube lengths pull the torque down to a lower R.P.M. range. Shorter tubes move the power band up into a higher R.P.M. range. The amount of straight in the collector extension can move the engines torque up or down in the R.P.M. range. Longer extension length will pull the torque down into the midrange.

Really most people design the intake, cams and header to be optimal at a certain RPM range as the standing wave can only be created at a single RPM. Good for dyno shootouts...not street driving.

IMO for street cars get a well constructed deisgn...not lips etc...nice joins at the collector and a design that suits your needs...i.e. low down torque and this will be fine.

Persaonlly I have had only minor gains (2-3%) from header/extractors bolt ons.

[drgnball34]

true...it is unfair to go bag something without proof. Any how i have ordered the HKS GT2835 with a .87a/r. I also am going to get internal work so will be pushing the turbo to its limits. That being said, with the 20+psi these huffers can get up to, besides the manifold, anything else is going to be restrivtive? I have tomei cams and onli 3"inch to cat and 3.5" there after. That may be a start?

[Cubes]

That ebay looking type exh manifold...

There's around 20rwkw gain once up over 300rwkw.

A couple of track days and it cracked, but it was an ebay type.. UAS may have them made better, who knows. I don't.

[r33_racer]

I know kylies manifolds arent tuned length...they are close but not spot on. He made one tuned length and one normal and did back to back testing and found no difference in power, lag, temperatures or back pressure, just abit more added weight to get some of the runners the same length. From what i gather so long as the merge point is seamlessly smooth and doesnt induce turbulence so you get one lot of gas running directly into another lot of gas like in my crappy s/s xsforce manifold then there shouldnt be any problems with it.

My crappy one that ive had for a good year or more stupidly has no.3 running straight up into the collector towards the flange which is great however no.2 comes straight in from the side of the collector runs directly into no.3's exhaust stream. As a result stainless being stainless with its shithouse ability to dissipate heat, that section of the collector and the affected runners localise all that turbulent heat and go white and build up and im getting bad back pressure and its causing my wastegate to fluctuate and when it all gets hot enough its recking my motors power making ability

Quick question. Has anyone had their std manifold extrude ported or honed? Whatever you call it. You know that place in Sydney that was doing it to the rb26 factory manifolds, and showing the flow differences between s/s a/m ones and their honed factory ones.

Edited November 16, 2006 by r33_racer

[tridentt150v]

Yes, I was wondering that as well, I am looking at buying a hks cast manifold low mount, but then started wondering if I extrude honed my std one would that do a similar job for half the cost?

I may even do both ie buy the hks unit and then get it extrude honed.

[Cubes]

Have you found some one that sells the hks cast mani for a reasonable price?

I remember when they used to go for 400-600 and then the price began to rise to around 800 then 1000 and then last I saw people were asking close to 1.2k for them. :S

The HKS cast mani could do with some smoothing out as it is cast after all.

When you get a hks mani in your hands and compare it to the std manifold there's simply no way the std item could flow as well as the hks item. Completely different design, smooth merges at the collector etc.

[sewid]

Why not get John to extrude hone your factory manifold and be done with it. You can then bolt on your factory heat shields and junk.

[drgnball34]

I spoke to the boys at UAS. They are not the ebay crap as stated before. The china ones are 2mm thick and use 302 steel. But all stainless will eventually crack. Street use should last awhile but on track, forget about it. It also comes donw to what turbo you are using. Since mine will be generating 20+psi, the heat would effect it dramitcally. They mentioned the other option on getting the standard one extrude honed. Any idea as to how much this can cost? Any noticeable gains in power? Weighting weather i should bit the bullet and go for a AM one but if i can get similar power from the standard one for half the price...WHY NOT?

[R31Nismoid]

But all stainless will eventually crack.

wrong

1987 HR31 GTS-R stainless manifold of mine, which is now on a good mates car has done 19 years of diligent service without one crack.

If the manifold is designed correctly, it will last as long as the car itself

[drgnball34]

Thank god i was just quoting what the UAS dude said.

[sewid]

I spoke to the boys at UAS. They are not the ebay crap as stated before. The china ones are 2mm thick and use 302 steel. But all stainless will eventually crack. Street use should last awhile but on track, forget about it. It also comes donw to what turbo you are using. Since mine will be generating 20+psi, the heat would effect it dramitcally. They mentioned the other option on getting the standard one extrude honed. Any idea as to how much this can cost? Any noticeable gains in power? Weighting weather i should bit the bullet and go for a AM one but if i can get similar power from the standard one for half the price...WHY NOT?

$500 or so to extrude hone factory manifold.

If you were to ever get an aftermarket manifold you would want to get it ceramic coated to keep engine bay temps down or expect to melt things... This adds another cost on top of the manifold. Very few of them mount the factory heat shields back on.