Unique Autosports Rb25det Exhaust Manifold

[r33_racer]

on those gts-r manifolds...how thick is the stainless used in those? Also what grade and what type of s/s? Being a good quality one id assume either 316 grade austenitic.

[R31Nismoid]

No idea what grade to be honest. Finding something out like that would be getting into some near impossible stuff i reckon.

I'll see if the thickness was measured before it was put back into my mates car... not sure though.

[drgnball34]

How about performance gains? Any where near what a aftermarket one can add? 6boost manifolds look like the way to go although $1200. How about thermal wrapping it instead?

[EvilINGT]

Im pretty sure there was a thread on here about this stuff before from the UAS guys.

Found some might make for interesting reading.

http://www.skylinesaustralia.com/forums/in...c=82555&hl=

http://www.skylinesaustralia.com/forums/in...c=67686&hl=

makes you think twice about buying that manifold and abrasive flowing the stocker.

cheers

Evil

[sewid]

How about performance gains? Any where near what a aftermarket one can add? 6boost manifolds look like the way to go although $1200. How about thermal wrapping it instead?

Thermal wrapping is, to be blunt, a f**king nightmare.... Ceramic or nothing...

[r33_racer]

yeh extrude honing maybe the go. Anyone have any idea what it costs to get an rb25 manifold done?

[sewid]

yeh extrude honing maybe the go. Anyone have any idea what it costs to get an rb25 manifold done?

Under $600 - call UAS and ask.

[SLY33]

Lol mine has just been done! ~500. Average 34cfm increase each runner, can get some pics later, its in the mail coming back to me now.

Main reason i did this was to retain the factory look when i have to pop the bonnet. made 281rwkw before, will be interesting to see if i can get any decent improvement.

[Cubes]

Good stuff Sly.

Considered getting the inlet mani/runners done at a later date?

[SLY33]

Good stuff Sly.

Considered getting the inlet mani/runners done at a later date?

hadnt thought of that, the only reason we did the manifold now was coz we had the turbo off due to defect, so while we were there...

I dont feel that the car needs more power, i think its more a matter of interest whether we can see some more kw's from improving a stock component Ive always thought the stock inlet mani did a pretty good job. We'll see how we go with the exh mani results!

[tridentt150v]

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.

Not yet, waiting for one to turn up, I've asked around/put the word out, so I'll wait and see. But I reckon if I can get one for the 1k mark, I'll be happy. i can be sort of patient.

[r33_racer]

500 bux hey...seems good enough to me...might hold off until you find out what sort of increase it achieves if any.

[legend01]

Some flow rates for you guy's from extrusion flow honing standard manifold ,hks cast iron manifold and hks cast iron flow honed

standard manifold .........hks cast ...............hks cast flow honed

1 159.7.........................170.7............................194.8

2 162.4.........................166.6............................203.4

3 160.7.........................178.7............................198.7

4 150.1.........................183.6............................200.3

5 149.9.........................182.2............................207.8

6 173.3.........................184.7............................202.8

Do not have any figger's for standard manifold flow honed but I do no he did a comparison between the standard manifold and a side mount s/s manifold like the one posted earlier in this thread and advised his customer to go with the standard manifold as a result last time I was there the s/s one was still there and he used it as an example of what not to buy ,I don't know if it was an ebay one or where it came from I'm just posting what he advised me as my son was after one of these same s/s manifolds and has opted instead to get his standard manifold flow honed instead when funds allow .As you can see flow honeing does make huge differances I also had the front cover and hot side of a gt3040r flowed honed at the same time to help with spoolup and it does work though I have no flow rates for these

Cheers Peter

[discopotato03]

I know of an article about a HKS turbine housing that was extrude honed in the US , I think there were some before and after shots as well . If I can find it I'll give directions because I'm not computer literate enough to know how to post links .

What I do know is that part of the cost of this process is for making a feed devise to bolt to the item to be honed . If we are smart about this and use one or a small number of firms the economies of scale could help out price wise .

Also importantly the people doing this work need to know and make sure they don't take too much out with this process because a huge oversize is not always an overall benefit . With turbine housings it can work very well mainly because it takes the ridges off the internal passage and reduces the depth of that boundary layer effect you get with fluid flow . Also any casting flash goes as well . The process is good for manifolds because it takes more from the constriction points ie round bends where its difficult/impossible to get at any other way .

Provided the operator can be convinced that the item only needs a clean up all should be ok . Either Zoom or HPI ran an article ages ago where I think A VG20 quad cam engine had its inlet manifold runners "daylighted" by a large amount . I think they also "Bridgeported" a VL turbo inlet manifold as well .

So care needs to be taken because it would not be difficult to make you nice expensive rare housing/manifold useless .

Watching this space because there is the potential to get significant gains from externally std looking components . What the whallopers can't see can't hurt you I reckon .

Cheers A .

[B-Man]

6boost manifolds are quite impressive.

[legend01]

Discopotato03 is correct when my hks manifold was done it honed into one of the stud holes for the turbo .As the manifold was made for the earlier t4 style of flange I had it drilled and taped for the t3 flange ,it was one of the older t4 stud holes that had been holed it was a matter of removing the turbo again and inserting a grub screw, this time an easy fix but it highlights what can happen if to much is taken out.

Cheers Peter

[Scooby]

I was extremely interested in getting my Rb26 manifolds hones as like you guys I see it as a great solution. When UAS posted their flow bench tests on this forum some time ago I replied and asked John to prove that the honing process produced real world ie on-car improvements that justified the cost. Those improvements could be lower/sooner boost, reduced temps, more power or torque - pretty much any of the usual things people look for.

Respect to John for agreeing to test them on my car. The idea was for us to come to an agreement about what represents a reasonable improvement, and work out the costs if it didn't produce.

Unfortunately the test never went ahead so if anyone has real world results please share them because I'd still like to get it done, but I'm not going to spend $500 because it 'should' work in the real world.

Cheers

Edited November 17, 2006 by Scooby

[r33_racer]

thats where i stand as well Scooby. Hopefully SLY33 will be able to share his experience with this when his is all setup.

[Cubes]

Legend...

http://www.skylinesaustralia.com/forums/in...c=82555&hl=

The above link has the std manifold flow rates and after its been extrude honed.

[legend01]

Hi Cubes

Thank you, Yes I know ,there for the gtr manifolds I think you'll find ,It does indicate the gains that can be had though as with the hks be4 and after in my above thread ^^^^ show's

Cheers Peter