Hpi Exhust Manifold Worth It?

[R31Nismoid]

To answer the initial Q - No, you do not need to change the manifold, it is a waste of money.

The stock manifold runs into issues around the 300rwkw-320rwkw region, which is basically when you rebuild the motor

If you are below that, stock motor etc etc save your pennies. You aren't going to get gains to justfiy the costs.

To the others asking about lowmounts and piping - of course it will change. There won't be one manifold that will be direct replacement.

I have the same thoughts on the RB30, I realise you should go a bigger turbo, but I'd be keen to see how it goes with the GTRS. Surely even being chocked up it won't make less power than my RB25, but with a heap more torque low down.

What you'll probably find is the car feels lifeless about 6500rpm because the turbo is running out of puff and the rear housing is making a mess of the situation as well.

So while it'll come on earlier, don't expect it to hold until 7000-7500rpm. You'll be looking to grab gears much sooner.

[Ryno]

Good advise.

I've got a spare standard manifold lying round, so I may do some port matching, get it ceramic coated and leave it at that.

[WARLORD]

there is a new style coming out that i have been waiting for over 7 months better collector and bigger runners,i have been in contact with the man who has built it and will be selling it soon,unfortunately the company he got to make it has sold the design to many other shops,his will be sold made from 321 S/S 3mm the copies will be made from 303 S/S 2mm,hpi will also be selling his manifold at a huge price,

here is a pic of the copied one.

by the way this is direct replacement.

Edited January 21, 2010 by WARLORD

[Ryno]

It's a shame you can't get it in steam pipe (like the 6Boost manifold). Any idea what the 3mm 321 S/S will sell for?

[seraphyn_r33]

a big +1 to nismoids post, take that advice on board because what he said is 100% true

[WARLORD]

It's a shame you can't get it in steam pipe (like the 6Boost manifold). Any idea what the 3mm 321 S/S will sell for?

nothing wrong with 321 s/s,they don't crack like 304 sus.they will be about $720 (depending on us dollar) delivered in Australia to the door.ill be getting one of the first and testing it on my set up.

Edited January 22, 2010 by WARLORD

[DCIEVE]

I can't believe people are seriously considering these manifolds. I ran a chinese version of the hpi manifold pictured on p1 years back on an rb20/td06 set-up. After chasing my tail for a few months wondering why it wasn't making any power I came to my senses and stuck the stock manifold back on - and instantly found 60+ rwhp.

[2BNVS]

i agree with Titan in earlier post. I bought a manifold from Leigh ETM and got it ceramic coated, with still plenty of change. and it looks shit hot too

[Ryno]

nothing wrong with 321 s/s,they don't crack like 304 sus.they will be about $720 (depending on us dollar) delivered in Australia to the door.ill be getting one of the first and testing it on my set up.

Lucky you... How long before we will get to hear your results?

[R31Nismoid]

I can't believe people are seriously considering these manifolds. I ran a chinese version of the hpi manifold pictured on p1 years back on an rb20/td06 set-up. After chasing my tail for a few months wondering why it wasn't making any power I came to my senses and stuck the stock manifold back on - and instantly found 60+ rwhp.

The worst part is they are charging $1700 for it, but its without question from a China factory, costing $300

[WARLORD]

Lucky you... How long before we will get to hear your results?

in a few months as im still part hunting

i have most things just need a baffled sump from somewhere,and a few little things, and some more cash...lol

but as soon as i get the result im looking for ill post it up.

Edited January 22, 2010 by WARLORD

[Cartman]

nothing wrong with 321 s/s,they don't crack like 304 sus.they will be about $720 (depending on us dollar) delivered in Australia to the door.ill be getting one of the first and testing it on my set up.

the main reason manifolds crack is due to the exhaust system not being supported properly, and if my memory serves me properly from tafedays... 304 is more durable for exhaust manifolds, due to the propertys in 321 its more prone to heat stress cracks as its a harder metal

in saying that tho i've always used 304 for all my exhaust work but i havent made a manifold out of it as steam pipe is cheaper and holds the heat in better but not once have i had any 304 crack on me its all in the mounting brackets and flex joints help.

Edited January 22, 2010 by Cartman

[WARLORD]

the main reason manifolds crack is due to the exhaust system not being supported properly, and if my memory serves me properly from tafedays... 304 is more durable for exhaust manifolds, due to the propertys in 321 its more prone to heat stress cracks as its a harder metal

in saying that tho i've always used 304 for all my exhaust work but i havent made a manifold out of it as steam pipe is cheaper and holds the heat in better but not once have i had any 304 crack on me its all in the mounting brackets and flex joints help.

funny the guy who makes them in japan said the opposite about 304 being the lesser material than 321 as 321 has a much higher heat resistance.

of the net

321 is the grade of choice for applications in the temperature range of up to about 900°C, combining high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion.

Grade 304 is more readily available in most product forms, and so is generally used in preference to 321 if the requirement is simply for resistance to intergranular corrosion after welding. However 304 has lower hot strength than 321 and so is not the best choice if the requirement is resistance to an operating environment over about 500°C

more info http://www.viperalley.com/forum/viper-disc...-stainless.html

Edited January 22, 2010 by WARLORD

[Guilt-Toy]

are you guys heat wrapping stainless manifolds??? NOOO!!!!

[WARLORD]

are you guys heat wrapping stainless manifolds??? NOOO!!!!

??????

[Cartman]

funny the guy who makes them in japan said the opposite about 304 being the lesser material than 321 as 321 has a much higher heat resistance.

of the net

321 is the grade of choice for applications in the temperature range of up to about 900°C, combining high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion.

Grade 304 is more readily available in most product forms, and so is generally used in preference to 321 if the requirement is simply for resistance to intergranular corrosion after welding. However 304 has lower hot strength than 321 and so is not the best choice if the requirement is resistance to an operating environment over about 500°C

more info http://www.viperalley.com/forum/viper-disc...-stainless.html

has been a long time since i got taught all that shit, but i use 304 for everything and have never once had it crack, i'll be making a turbo manifold soon for one of my own cars providing i can get the bends cheap enough i'll test it out, could get scary pricing up 20 or so bends in small sizes but will see how it goes when ever i get around to doin it 

[Kaido_RR]

Was looking at exhuast manifolds and was looking at this hpi one at just jap priced for 1700 which says it keeps the exact stock postion. Now my question is is this a worthwhile to consider getting considering I got the usual mods turbo injectors ecu etc. 270kw , How much more benifet could I receive over the stock manifold?

shit design. if you want a j-spec brand get HKS