Rb26 Single Turbo Exhaust Manifolds

[saliya]

Hi folks,

well, in the process of making final decision for turbo + exhaust manifolding for my car, and I'm trying to

decide which is the best exhaust manifold for my proposed setup (RB26, T04Z + 38-44mm external gate).

Background: there are 2 T04Z exhaust housings that I'm considering; the 0.81 single-entry and the 0.84 split-pulse.

I'm told that the single-entry 0.81 housing _can_ be had for money from Garrett (don't know how different this is from

the HKS single-entry housing but I'm not considering the HKS turbo at all at this stage).

I haven't managed to find a new cast RB26 single turbo manifold (I think HKS and a few others used to make them)

so I've discarded the idea of going this way.

I've been recommended to use stainless because of the bad oxidation properties of mild steel at very high temperatures.

I've been recommended to use mild steel because it's less likely to crack than stainless.

I'm told that if the stainless is put together properly and designed for expansion properly, it shouldn't crack.

I'm told that stainless manifolds always crack.

Some of these statements could be held to be mutually-exclusive

I'm looking at the following options:

* New Trust stainless, $?, don't read Japanese too well and it doesn't look like it's readily available individually

* New HKS stainless, $1500ish

* 6boost mild steel, $1200ish, can be either single-entry or split-pulse, wastegate flange to suit my wg

* XTR premade stainless, $1100ish, T3 flange non split-pulse, flange to suit 44mm tial gate

* N*power premade stainless $700ish, T4 split-pulse flange, flange to suit various wgs

* Ebay-and-the-like used product, nonexistent < $2000 at this time

* Ebay-and-the-like new product "HKS-style" $350

edit: add exhaust mounting locations and manner because they might be important

Can anyone that has an RB26 single conversion post on their exhaust manifold experiences? PM me if you like,

or cut/paste the very next part into your reply.

* who made it?

* how much it was?

* when it was installed?

* what HP you are running?

* what material?

* tuned-length or not?

* split-pulse or not?

* any problems you've had (cracking, rusting, other type of failure)?

* list the mount points and manner of the rest of the exhaust: e.g. 'flexible hanger off gearbox, flexible hanger near rear axle, flexible hangers above rear muffler'?

* your overall impression of it and any other information that you think is worthwhile?

* any recommendation from the above options?

end cut/paste part

edit: added n-power 2006-04-11

edit: added trust 2006-04-16

* who made it: Trust:

* what material: stainless

* tuned-length or not: unknown

* split-pulse or not: split-pulse

* how much it was: unknown

* when it was installed: 1 month ago

* any problems you've had (cracking, rusting, other type of failure)? none yet

edit: added 2nd trust 2006-06-30

* who made it: trust

* how much it was: unknown

* when it was installed: unknown, 5000km ago

* what HP you are running: unknown

* what material: stainless

* tuned-length or not: tuned-length

* split-pulse or not: split-pulse?

* any problems you've had (cracking, rusting, other type of failure)? cracked

* list the mount points and manner of the rest of the exhaust: e.g. 'flexible hanger off gearbox, flexible hanger near rear axle, flexible hangers above rear muffler'? unknown

* your overall impression of it and any other information that you think is worthwhile

* any recommendation from the above options

edit: added hks 2006-04-16

* who made it: HKS

* what material: stainless

* tuned-length or not: tuned-length

* split-pulse or not: split-pulse

* how much it was: $1500

* any problems you've had (cracking, rusting, other type of failure)? none

* your overall impression of it: very satisfied.

edit: added hks cast 2006-06-27

* who made it: HKS

* what material: cast iron

* tuned-length or not: no

* split-pulse or not: no

* how much it was: $500

* any problems you've had: cracking, mild surface rust

* your overall impression of it: not overly impressed.

edit: added 6boost mild steel 2006-06-27

* who made it: Kyle Hopf, 6boost

* how much it was: $1240

* when it was installed: still in progress

* what HP you are running: aim 500HP

* what material: mild steel

* tuned-length or not: looks like equal-length; what RPM tuned for don't know

* split-pulse or not: split-pulse

* any problems you've had (cracking, rusting, other type of failure)? none yet

* your overall impression of it and any other information that you think is worthwhile: manifold itself is

nice work. Had to make a few phone calls when not received on agreed date. Fair price.

* any recommendation from the above options: none yet.

edit: added ebay stainless 2006-06-30

* who made it: ebay?

* how much it was: $350?

* when it was installed: August2005

* what HP you are running: 600?rwhp

* what material: stainless

* tuned-length or not: unknown, looks like tuned-length

* split-pulse or not: split-pulse

* any problems you've had (cracking, rusting, other type of failure)? none

* list the mount points and manner of the rest of the exhaust: e.g. 'flexible hanger off gearbox, flexible hanger near rear axle, flexible hangers above rear muffler'? unknown

* your overall impression of it and any other information that you think is worthwhile: has not broken

* any recommendation from the above options: sounds like it's a very good deal.

edit: added custom racepace 2006-06-30

* who made it? Ben @ racepace, 9/6 Halloway Drive, Bayswater 9762 9421

* how much it was? depends on requirements:P unsure of exact cost because project is 4 years old

* when it was installed? 4 years ago

* what HP you are running? 420-430kw

* what material? unknown

* tuned-length or not? unknown

* split-pulse or not? unknown

* any problems you've had (cracking, rusting, other type of failure)? none

* list the mount points and manner of the rest of the exhaust: e.g. 'flexible hanger off gearbox, flexible hanger near rear axle, flexible hangers above rear muffler'? unknown

* your overall impression of it and any other information that you think is worthwhile? Never had problems with it. Perfect condition even after all the pain we've put it through

* any recommendation from the above options? Anything made by Ben is worthwhile. Perfection at it's best.

Regards,

Saliya

Edited June 30, 2006 by saliya

[saliya]

Nobody?

Update: Got a HKS RB26 cast manifold 2ndhand, it's cracked and re-welding a cast

cracked manifold is a _bitch_ of a job. Sending it back on Monday, so still looking.

Votes for Trust stainless manifold to suit T78/T88 (apparently it's a T04 flange) from people on the forum.

SW

Edited April 15, 2006 by saliya

[CruiseLiner]

Nobody?

Update: Got a HKS RB26 cast manifold 2ndhand, it's cracked and re-welding a cast

cracked manifold is a _bitch_ of a job. Sending it back on Monday, so still looking.

Votes for Trust stainless manifold to suit T78/T88 (apparently it's a T04 flange) from people on the forum.

SW

trust t78/88 manifold is sweet, looks nice, havent used mine yet (well only 300km use) so i dunno about durability, but the jap gear is usually good. much better than the ebay crap ive seen around

[SRB]

ive got a hks one, that came with my kit, absolute mint. other than that id highly recomend the 6boost manifolds, seen them and they are awesome!!! u get wat u pay for buddy, keep that in mind

[dangerous_daveo]

What I have been told is stainless is no longer stainless after it reaches a certin temp. And this is where the apparent problem is. I've always been told steam pipe (is this the same as mild steel?) as its far less likely to crack as you can use a different weld, it holds in the heat better (exaust side not always a problem, hotter air is thinner, thinner air moves faster, spool quicker...) Which is I guess is also the reason the cast ones are good. Give you something else to think about.

[R32-GTS]

My shitty Ebay manifold has been going good for 8months now . No cracks etc ( touch would ) . Its made outta stainless steel.

[AlexCim]

stock manifold is mild steel....

[600hp]

I've just mounted up our stainless Trust item which i purchased of doughboy how is on this forum(T88 kit).

he had some other jap brands as well give him a pm for prices.

Cheers

[saliya]

Finally have some time.

pics of cast HKS cast manifold showing cracks.

[saliya]

Update:

Ordered 6boost manifold on 2006-05-17, quoted 10 days to completion. $1200 PLUS shipping.

Received manifold 2006-06-02, no flange for wastegate.

Update: I had to attach wastegate thick-walled piping plus the flange; adding around $30

to the cost of the manifold. I thought wastegate piping would be included but apparently not

with mine.

Overall construction quality seems very good; details of split-pulse collector show what

a nice job has been done.

Update: An entire weld was missed in construction (pics to be added soon) which I had to

have welded so the manifold would not leak. Moral of the story: check each weld on the

manifold thoroughly when you receive it. No, I have not contacted Kyle about this. There's

nothing he can do to change it; and I'm not going to hide the facts. Hopefully the next one

I buy will be _perfect_

Welds where visible internally have been die-ground; small internal steps can be felt where there

are joins but it was not possible to get a die-grinder to.

Placement of turbo looks roughly equivalent to HKS T04Z kit; interference with power steering

reservoir on R32 is pretty much a given. I don't know if this is the case with the 'bolt up'

HKS kits, but I had to move my p/s reservoir and hoses. I've also had to move the air/water

lines that run around the back of the RB26 as leaving them there results in a lot less room

for exhaust + gate.

Saliya

Edited October 5, 2006 by saliya

[Gts-t]

Update:

Ordered 6boost manifold on 2006-05-17, quoted 10 days to completion. $1200 PLUS shipping.

Received manifold 2006-06-02, no flange for wastegate.

Overall construction quality seems very good; details of split-pulse collector show what

a nice job has been done.

Welds where visible internally have been die-ground; small internal steps can be felt where there

are joins but it was not possible to get a die-grinder to.

Placement of turbo looks roughly equivalent to HKS T04Z kit; interference with power steering

reservoir on R32 is pretty much a given. I don't know if this is the case with the 'bolt up'

HKS kits, but I had to move my p/s reservoir and hoses. I've also had to move the air/water

lines that run around the back of the RB26 as leaving them there results in a lot less room

for exhaust + gate.

Saliya

I think the one on the gcg website looks the goods!

Check it out if its not the XTR one you mention

[saliya]

I think the one on the gcg website looks the goods!

Check it out if its not the XTR one you mention

Thanks,

Yes, this is the XTR one. It's not really suitable for a T04Z because it has the wrong flange (T3)

and it's not split-pulse. You could put a T4 flange on it, but it still wouldn't be quite right.

Either the other folks that have done this have all posted already, or can't be arsed. With

so many opinions on it out there I'd have thought more people had actually _done_ it

Regards,

Saliya

[djr81]

What I have been told is stainless is no longer stainless after it reaches a certin temp. And this is where the apparent problem is. I've always been told steam pipe (is this the same as mild steel?) as its far less likely to crack as you can use a different weld, it holds in the heat better (exaust side not always a problem, hotter air is thinner, thinner air moves faster, spool quicker...) Which is I guess is also the reason the cast ones are good. Give you something else to think about.

Um, sorry but it is still stainless steel. What does happen is that the yield strength of the material deteriorates as temperatures rise. Additionally stainless steel has a much higher coefficient of thermal expansion than carbon steel(s). Combine this with the thinner gauges typically used (relative to carbon steel) and in a poorly designed system you can get cracking.

I've always been told steam pipe (is this the same as mild steel?) as its far less likely to crack as you can use a different weld, it holds in the heat better (exaust side not always a problem, hotter air is thinner, thinner air moves faster, spool quicker...)

"Steam" pipe (I wish people wouldn't call it that) is not mild steel. It is a relatively high yield strength carbon steel and is used with any number of materials aside from steam.

Welding done properly (For same - same metals, ie not dissimilar materials) should deposit metal that is the same as or better than the parent material.

Cast and/or fabricated carbon steel manifold tend to retain heat better mostly because they are thicker than equivalent stainless steel manifolds.

Edited June 27, 2006 by djr81

[B-Man]

Hey - Good thread here - thanks for going to the time to put it together.

I have been researching the 6boost manifold as they look the goods. The VL guys are happy with them.

I tried to get in contact with the 6boost dude in qld - but no return e-mail

Where did you get yours from ??

[saliya]

Hey - Good thread here - thanks for going to the time to put it together.

I have been researching the 6boost manifold as they look the goods. The VL guys are happy with them.

I tried to get in contact with the 6boost dude in qld - but no return e-mail

Where did you get yours from ??

Hi,

I got it directly from Kyle; I found that it was better to contact him via phone than email;

but I guess this will get better as his business grows ( or not, who knows )

Since his number is on his website (www.6boost.com) I'd say that he won't mind

me posting it here - 0410 730 598. Be warned - I needed to chase him up for delivery.

As always, YMMV. The final product is, IMO (and at this stage!), very good value for money.

You can also get them from Morrie Huckel @ horsepowerinabox; and Tarek @ Racespec.

Tarek's on the forums as 'Racespec' I think, and Morrie is very easy to get hold of.

Regards,

Saliya

[BezerkR32]

I have a thread running in here somwhere about a RB26 single turbo upgrade. Used the GCG mstainless manifold with the GCG 35/66 SPL & 48mm turbosmart wastegate. has been on car for over 2 months and is a daily driver, no problems thus far. Car has hade mild tune done. 275rwkw on 12.5 psi. going for final tune this week. Turbo is very drivable. Ill try to link to thread but not sure how.http://www.skylinesaustralia.com/forums/index.php?showtopic=119136&hl=

Hi folks,

well, in the process of making final decision for turbo + exhaust manifolding for my car, and I'm trying to

decide which is the best exhaust manifold for my proposed setup (RB26, T04Z + 38-44mm external gate).

Background: there are 2 T04Z exhaust housings that I'm considering; the 0.81 single-entry and the 0.84 split-pulse.

I'm told that the single-entry 0.81 housing _can_ be had for money from Garrett (don't know how different this is from

the HKS single-entry housing but I'm not considering the HKS turbo at all at this stage).

I haven't managed to find a new cast RB26 single turbo manifold (I think HKS and a few others used to make them)

so I've discarded the idea of going this way.

I've been recommended to use stainless because of the bad oxidation properties of mild steel at very high temperatures.

I've been recommended to use mild steel because it's less likely to crack than stainless.

I'm told that if the stainless is put together properly and designed for expansion properly, it shouldn't crack.

I'm told that stainless manifolds always crack.

Some of these statements could be held to be mutually-exclusive

I'm looking at the following options:

* New Trust stainless, $?, don't read Japanese too well and it doesn't look like it's readily available individually

* New HKS stainless, $1500ish

* 6boost mild steel, $1200ish, can be either single-entry or split-pulse, wastegate flange to suit my wg

* XTR premade stainless, $1100ish, T3 flange non split-pulse, flange to suit 44mm tial gate

* N*power premade stainless $700ish, T4 split-pulse flange, flange to suit various wgs

* Ebay-and-the-like used product, nonexistent < $2000 at this time

* Ebay-and-the-like new product "HKS-style" $350

Can anyone that has an RB26 single conversion post on their exhaust manifold experiences? PM me if you like

* who made it

* how much it was

* when it was installed

* what HP you are running

* what material

* tuned-length or not

* split-pulse or not

* any problems you've had (cracking, rusting, other type of failure)

* your overall impression of it and any other information that you think is worthwhile

* any recommendation from the above options

edit: added n-power 2006-04-11

edit: added trust 2006-04-16

* who made it: Trust:

* what material: stainless

* tuned-length or not: unknown

* split-pulse or not: split-pulse

* how much it was: unknown

* when it was installed: 1 month ago

* any problems you've had (cracking, rusting, other type of failure): none yet

edit: added hks 2006-04-16

* who made it: HKS

* what material: stainless

* tuned-length or not: tuned-length

* split-pulse or not: split-pulse

* how much it was: $1500

* any problems you've had (cracking, rusting, other type of failure): none

* your overall impression of it: very satisfied.

edit: added hks cast 2006-06-27

* who made it: HKS

* what material: cast iron

* tuned-length or not: no

* split-pulse or not: no

* how much it was: $500

* any problems you've had: cracking, mild surface rust

* your overall impression of it: not overly impressed.

edit: added 6boost mild steel 2006-06-27

* who made it: Kyle Hopf, 6boost

* how much it was: $1240

* when it was installed: still in progress

* what HP you are running: aim 500HP

* what material: mild steel

* tuned-length or not: looks like equal-length; what RPM tuned for don't know

* split-pulse or not: split-pulse

* any problems you've had (cracking, rusting, other type of failure): none yet

* your overall impression of it and any other information that you think is worthwhile: manifold itself is

nice work. Had to make a few phone calls when not received on agreed date. Fair price.

* any recommendation from the above options: none yet.

Regards,

Saliya

Edited June 27, 2006 by BezerkR32

[saliya]

Um, sorry but it is still stainless steel. What does happen is that the yield strength of the material deteriorates as temperatures rise. Additionally stainless steel has a much higher coefficient of thermal expansion than carbon steel(s). Combine this with the thinner gauges typically used (relative to carbon steel) and in a poorly designed system you can get cracking.

Cast and/or fabricated carbon steel manifold tend to retain heat better mostly because they are thicker than equivalent stainless steel manifolds.

Looks like I've found something we can agree on

For anyone that's interested, Carroll Smith's 'Foo' to Win series have some useful things to say about metals

and their properties. Engineer to Win is probably the most relevant here but there is some overlap within

the series.

Regards,

Saliya

[djr81]

Yeah Carroll Smith has some useful things to say, but the info contained within his books is now getting somewhat dated.

[felixy69]

i have a trust t78/t88 manifold after 5000kms the manifold started cracking....

i might give the ebay manifold a try !!

[Sydneykid]

Most times I see cracked manifolds it is because the whole weight of the exhaust system is hanging off the turbo. So many cars don’t have the solid mounting bracket at the bell housing and the flexible mount at the gearbox cross member. The weight of the entire exhaust hangs of 2 rubber mounts at the rear muffler and the turbine flange at the front. It’s any wonder that the manifold cracks, carrying the weight of the turbo itself and half the exhaust system, swinging around.

If you support the weight of the turbo, the external wastegate (if it has one) and the exhaust system properly, then all the manifold has to do is hold in the exhaust gas. Which doesn’t require huge thicknesses of stainless steel.

If you are concerned with a thin (ish) walled stainless manifold, spend $50 and get a couple of supports welded on from the turbine/manifold flange to the manifold/cylinder head flange. That will stop any flexing in the pipework itself.

cheers