Jump to content
SAU Community

Recommended Posts

hi looking at upgrading my exhaust manifold and wanting some advise form people who have. ive upgraded the turbo to a 500ps unit and it sits on the standard mani with a custom twin dump/front pipe. So if anyone can tell me were to get a good manifold that locates back to the stock turbo position would be great. also the gains they have got from doing it . what is the most hp a stock manifold on a rb25 can support?

cheers guys

hi looking at upgrading my exhaust manifold and wanting some advise form people who have. ive upgraded the turbo to a 500ps unit and it sits on the standard mani with a custom twin dump/front pipe. So if anyone can tell me were to get a good manifold that locates back to the stock turbo position would be great. also the gains they have got from doing it . what is the most hp a stock manifold on a rb25 can support?

cheers guys

Hi i can have made for you a custom exhaust manifold in stainless steal,but its expensive.i all so can supply plenium kits and inlets for rb20,25,30.contact me at

[email protected].I can send pics of all item.good kw gains

cheers steve k

I have one of those china manifolds and they look good dunno if it makes more power but,I guess I'll find out soon :wassup:

Here's some pics of mine

China power 1

China power 2

China power 3

China power 4

I have got one like r31 power's to slap on my rb25 but i have to say it doesn't really look like any sort of improvment maybe even more restrictive then the stock log. It wouldn't really suprise me if people with these things are loosing power....but they look pritty from above. :headspin:

Live and learn i guess but i would be going for something custom next time round or a jap one and not a cheap pre-fab thing.

John

r31 power;

cool let me know how it goes. might be ok because i think there trying to replica a hks. someone was telling me they have problems with them leeking and cracking when getting real hot. thanks for the pics. Did you order it from the site, how long did it take and what was the total cost after shipping?

cheers.

The reports I'm getting about these chinese manifolds via anecdotes is that work better than you'd expect and they are stronger than what you've heard about SS manifolds.

Some grinding is needed to get them to fit but nothing a competant shop can't work out.

T.

Have you ever noticed that these spaghetti leg fabed manifiolds (the locally made ones) look like a nest of snakes ? I have to wonder if the contorted angles that some of the tubes use when they reach the collector are much good . Some US designs merge the primaries into a single tube which then feeds the turbo , the WRC engines seem to do this too . At least then the primaries are facing the desired direction and not wasting gas velocily and heat energy trying to oxy the collector off . On a six cylinder engine I recon the split pulse (123,456) would be easier to produce (than spaghetti special) and give better response and less reversion , also access to the turbo is better .

HKS do cast iron manifolds for RB20/25/26 (single turbo) which are along these lines and usually have provision for an external waste gate . If you can find one of these it would have the advantage of cast iron (less chance of cracking/warping) a guaranteed fit and the opportunity to use a higher performance waste gate system later if you need to . Also if you can do this part for reasonable money it has the potential to open a lot doors to future upgrades . Its no problem to make a cover plate for the external gate mount if you need to use an integral one for cost or cop reasons . You'll stand a better chance of convincing Joe average Wood Duck that its factory rather than the scaffold and ****y poo custom job .

Just my two paseos worth , cheers A .

The reports I'm getting about these chinese manifolds via anecdotes is that work better than you'd expect and they are stronger than what you've heard about SS manifolds.

Some grinding is needed to get them to fit but nothing a competant shop can't work out.

T.

This is good news for me... i was starting to think i'd wasted my money. :D

Now this grinding? where? is there much of it to be done. i have just got my head back and have not test fit it yet.

Also discopotato yes i know there are some horrible aussie custom ones floating around and like you said aussie ones tend to favour the long runner equal length design. I think i saw a few threads on the short runner jap manifolds vs aussie ones on here and performance forums ages ago.

John

ive got one those chinese manifolds, power has gone from 212rwkws at 17.5psi to 224 rwkws at 17.5psi, you be the judge.

Carl,

People also report a much nicer sound and more throttle response. Do you get this?

I love a car that leaps off the line and goes from 60-80-100 in a jump.

T.

Its good to hear people are getting good results from these.

I haven't even got my one on the head yet so i have no practical knowage of how they work in the real world yet.

Its just I was a little bit dissapointed in the clean-up & weld quality inside the runners on my one but if it works. :cooldance:

I will have my engine back together in a week or two so i'll let you guys know how it goes.

John

PS thats a nice markup they are putting on those at autobarn. :uhh:

Has anyone thought about an R31 GTSR original or better copy? To look at they are a damn sight prettier, and normally of it looks right then it works right.

My 2c is no matter which manifold you get, wrap it up in it jammies:) Mine is ceramic coated and it works ok but under bonnet temps still go through the roof, so when i get the car back ill be giving it a once over with high temp exhaust wrap. That and brace the turbo up off the head so that the thin walled 800deg C exhaust isnt relied upon to support the weight of the turbo

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...