This Manifold Vs Stock

[R31Nismoid]

look @ the turbine housing on the stock turbo after the flange where it tapers in.

The inlet it tiny, IMO cost for gain again renders it unviable

[infected flow]

infected flow,

nar no shit fight...

The stock manifold tends to 'really' hit a brick wall at around if not slightly before 300rwkw.

But as you said... good gains can be had earlier. The crappy china manifold the op is comparing to shiet and worth while sticking with the stock manifold.

What manifold did you go with out of curiosity?

the manifold i chose was hpi...

okay u can get 250-300rwkw with the standard manifold but your pushing shit up hill with the turbo .. so i still dont know where u get the idea that anything over 300rwkw change the manifold crap came from.u can get one from justjap $600-700 bucks..mmm

and no boost issues and only manifold and dump changed but dump was same size as previous.!

and as for proof

has anyone actually compared the standard to an aftermarket one....that should answer your question if its worth while!.

[Cubes]

1. so i still dont know where u get the idea that anything over 300rwkw change the manifold crap came from.

and as for proof

2. has anyone actually compared the standard to an aftermarket one....that should answer your question if its worth while!.

1. Dyno

2. See 1. GT35r .82 went from very low 300rwkw (on 18psi from memory) to 336rwkw on the same boost by simply dropping on a nice exh. manifold. Also numerous RB25's and RB30's on the dyno I run on that have hit a brick wall around 300rwkw. It literally is a brick wall. I haven't seen any start pushing 330rwkw on the stock exh. manifold. Those cheapo china exh. manifolds do zilch, well so the dyno says.

[700HP-GTR33]

I have one of those dodgy manifold and it was one of the many waste of times and money things I have done.

I'm going back to the stock manifold when I get a new turbs.

Stick with the stock one.

Hi guys,

I am curious when do you label a manifold dodgy?

What makes a Manifold dodgy? Name marked on it ?

Surely we need to name manufacturers, and types of manifolds that are on the market.

Before saying ...those cheap Chinese one's.

Just by saying near enough....they all fit in the same equation...all dodgy...is not good enough.

Give us serial numbers, and part numbers.

This Topic is going no-where.

Just people expressing there opinions and there previous experiences with manifolds.

What I am trying to say is........show your facts....post them up, with the type of manifolds used.

This might help others and might just help this guy make a better choice.

Cheers

[Color_Of_Green]

Im running 280rwkw on the standard manifold no probs. Would be better to extrude hone stock manifold than to go a cheapy after market one that is likely to flow less and crack.

UAS have flow tested, and dyno proven this against one similar to above.

HKS used to make a nice low mount for RB25DET but cant get them any more.

6Boost apparently flow nicely, but I have only seen top mount not low mount, and I have been waiting 10+ weeks for my low mount and still nothing.

If you are aiming for 300+ rwkw then you wouldnt be asking about this type of manifold IMHO.

Cheers

[Craved]

If you are aiming for 300+ rwkw then you wouldnt be asking about this type of manifold IMHO.

Cheers

another good point

if your paying $10K plus to get there .. spend that little more on a good manifold

that said though, my std manifold cracked with the std turbo.. so they arent full proof

[Busky2k]

Im running 280rwkw on the standard manifold no probs. Would be better to extrude hone stock manifold than to go a cheapy after market one that is likely to flow less and crack.

UAS have flow tested, and dyno proven this against one similar to above.

Cheers

How much would it cost to extrude hone a manifold? Last time I checked it was about (or even more than) $500 so its not exactly all that cheap either. In that case I'd probably just bite the bullet and get a quality equal length jobbie.

[Slide]

Extrude honing or abrasive honing wont make that much of a performance gain and definately not worth it for the price.

1 thou high casting grain is not the problem.

[RedDrifter]

Extrude honing or abrasive honing wont make that much of a performance gain and definately not worth it for the price.

1 thou high casting grain is not the problem.

I email the abbrassive honeing place and they basically told me to buy a HKS manifold.

Quote

We have flow tested one of those exhaust manifolds before and they dont flow that well but if you are looking to make serious power you should look out for a HKS exhaust manifold they flow a lot better than standard and make more power.

Regards

James

UnQuote.

Oh well

[infected flow]

1. Dyno

2. See 1. GT35r .82 went from very low 300rwkw (on 18psi from memory) to 336rwkw on the same boost by simply dropping on a nice exh. manifold. Also numerous RB25's and RB30's on the dyno I run on that have hit a brick wall around 300rwkw. It literally is a brick wall. I haven't seen any start pushing 330rwkw on the stock exh. manifold. Those cheapo china exh. manifolds do zilch, well so the dyno says.

YAY I AGREE TO A POINT!..Well i can safely say that on a r34 anything pass the 250-270 youll hit a brick wall..lol

[Cubes]

infected flow..

My cheapo china manifold do zilch comment appears to be incorrect. Well it was correct at lower power levels.

An rb25 making just under 300rwkw stock exh. manifold back to back with a china cheapo manifold picked up 20rwkw.

I should mention it wasn't a stock exh. manifold to china manifold it was vice versa.

He was running around with the china manifold on, blew a hole in it so went back to the stock exh. manifold and lost 20rwkw. Low mid was fairly similiar, just high mid-top end difference.

I don't care.. You speculate.. I know what I've seen on the dyno including back to back runs dyno displays.

[Busky2k]

Thats a nice gain for sure. Just over 5% (well 6.5%) which does seem about right yeah?

[700HP-GTR33]

Thats a nice gain for sure. Just over 5% (well 6.5%) which does seem about right yeah?

Hello again,

My guess would have been the same even without facts.

So we have improvements......everything counts.

So .........they are not shit...if built well.

Just by looking at a manifold does not cut it .Just because you do not agree with the way they bend.

Trying then and putting them on a dyno is a better way to evaluate them.

Cheers.

[Slide]

I email the abbrassive honeing place and they basically told me to buy a HKS manifold.

Quote

We have flow tested one of those exhaust manifolds before and they dont flow that well but if you are looking to make serious power you should look out for a HKS exhaust manifold they flow a lot better than standard and make more power.

Regards

James

UnQuote.

Oh well

There we have it.

[TurboX]

I bought one of the Exhaust manifolds shown but a HKS brand for $550 off SAU forum advertiser and it took two months to get it. Thought I had been dudded but got it eventually.

I fitted it along with a lot of other mods so cant say the difference it made but it has not cracked so far, but then again the car has been off the road a lot anyway.

The dyno results talked about do not reflect the on road drivability that this type of manifold might provide in comparison to the standard item.

I know we have to try to measure everything for comparison, but a dyno cannot tell the complete story regarding real world on road driving experience, and I dont drive at WOT everywhere in the city!

I am sure it somehow contributes to the efficiency of the power output and hopefully will know very soon after a dyno session with Dr. Drift now that I have replaced my faulty knock sensors.

[Color_Of_Green]

Look its always horses for courses and if you're chasing 300rwkw then like I said before the manifold in first post is not the one you would be interested in.

If your chasing 250-280 with low mount turbo + internal wastegate then stock one is fine so you spend the money somewhere else where its needed.. suspension / brakes / tyres ...

Cheers

[Cubes]

Look its always horses for courses and if you're chasing 300rwkw then like I said before the manifold in first post is not the one you would be interested in.

Well there's no point throwing one of those manifolds on to make a little more power only to find you have blown a hole in it as soon as you give it a bit of a hard time.

[infected flow]

infected flow..

My cheapo china manifold do zilch comment appears to be incorrect. Well it was correct at lower power levels.

An rb25 making just under 300rwkw stock exh. manifold back to back with a china cheapo manifold picked up 20rwkw.

I should mention it wasn't a stock exh. manifold to china manifold it was vice versa.

He was running around with the china manifold on, blew a hole in it so went back to the stock exh. manifold and lost 20rwkw. Low mid was fairly similiar, just high mid-top end difference.

I don't care.. You speculate.. I know what I've seen on the dyno including back to back runs dyno displays.

i dont speculate i know from experience as u do...and ive seen and done thats why i state it !

im just offering some input ...geez

BALLBREAKER!...ahhahahahahahaha

[W0rp3D]

i know this is an old thread but i believe it has relevance more than ever these days!

Look its always horses for courses and if you're chasing 300rwkw then like I said before the manifold in first post is not the one you would be interested in.

If your chasing 250-280 with low mount turbo + internal wastegate then stock one is fine so you spend the money somewhere else where its needed.. suspension / brakes / tyres ...

Cheers

Im thinking about going back to a standard exhaust manifold from a china copy, the one i have is a copy of a hpi, it came with the turbo set up i bought second hand with a 3540, i was hoping for a little over 300rwkw but so far have only made 250 on 18 psi, the tuner has pin pointed at least one thing that is holding it back, the xforce cat, but even after that is fixed he still only expects it to get 270-280.

One of the things i have been trying to do with this set up is to keep it looking as stock as possible, having the exhaust manifold rise to above the cam cover certainly dosnt help that, i have put a heat shield on it but it still dosnt help a whole lot, with the standard manifold i believe it would be easier to do these sorts of things, i could also use the factory bov return which atm i have no bov return because there is no space to route it, and then theres the china manifold mods.

When i got it the head flange was so bent there was 8mm difference from one end to the other, the easiest way to fix it was to cut the flange between each runner so when bolted up it would be easier to pull each one straight, but after/while doing that the gaps would close as saw as i had finished cutting them (killing 4 cutting discs) by the time i had cut big enough slots to have space the manifold was too short, the easiest way to fix this was to jam washers between each runner to space it out, in the end it was spaced just enough to get it on all studs, didnt think of it at the time but what are the chances that now the runners dont line up with the ports properly?

So the question is:

A) 5 years on is there any more proof(for or against) that the factory manifold is good up to 270-280rwkw?

B) If there is a power restriction at the level roughly how much is it?

C) Is there any way to improve the factory manifold?

or D)I should just spend the time making sure the china lines up and keep that?

[R31Nismoid]

A GT35 is a 350-380rwkw turbo, so @ 18psi if you are not over 300rwkw then most certainly there is something holding it back.

There are users who have ceraintly run 3071 and 3076 on a stock manifold upto 280rwkw, i believe there might be users with more but I am unsure of exactly who as i cant think of the threads they were posted in at the moment.

If you only want 280rwkw perhaps go back to the stock manifold and change turbo? You'd certainly notice a big difference @ 280rwkw with a 500hp turbo vs a 700hp one.