Jump to content
SAU Community

High vs low mount ex manifold: performance advantage?

180bfj20det
 Share

Recommended Posts

180bfj20det Community Regular

180bfj20det

Posted
Posted

Please support for "for and against" high and low mount" ex manifolds with respects to performance advantages.

From what I gather, I do NOT see "flow" benefits from either manifold type as flow is determined by inlet diameter, smoothness and diameter of bends in manifold runners (many other things including pressure but for the sake of the argument lets ket it relatively simple). I know of an associate who claims that low mounts flow better and I do not agree. I have built many ex manifolds and personally I have seen no advantage in either low or high in my designs.

This is not a thread of personal preferences but for performance-only cons and pros of the low and high mount manifolds. So please no "I think", just "it has been proven" or theory to support your opinions.

Cheers

Roy Grand Master

Roy

Posted
Posted

Well a few observations of my high mount setup. Oil lines are easy to suss, i suspect a low mount to be more awkward to run lines to/from turbo.

Also the dump pipe on my high mount is almost 2x90deg bends to clear the firewall then track the underside of the car....do i increase back pressure with 2 large 90 deg mandrel bends???? Id say bees d1ck difference, but a low mount does have a straighter shot to the backside of the car.

Also with alow mount i dont feel there is as much a need for heat shielding, sure you still got the steering rack etc down there you have to look out for, but my high mount sits lots wiring/bits & pieces next to glowing red steel:( It has taken me a while to get the temp / insulation to a point where im happy..

As for pure performance, id say maybe high mount as it gives you a bit more flexibility with pipe runs/layout...but again i think it comes down to a case by case basis as other factors are likely to influence performance more

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

lol, thats what i do... point... the big thing... down there :D

In all honestly i wish i had high mounted it now.

Everytime something dump/gate/turbo related has to be fiddled with its a 3 day adventure to get it apart.

Where a highmount would cost me no more than around 20mins if i scratch my ass a few times

Sydneykid Grand Master

Sydneykid

Posted
Posted

Personally I would much rather have the superior performance of a low mount and use reliable turbos and high quality installation so that i don't have to work on them all the time. A well engineered low mount doesn't present much more of an access problem, don't get trapped into comparing a aftermarket high mount with the factory low mount. You really need to compare it to an aftemarket low mount.

The superior performance is there all the time when I am driving it, any miniscule maintenance advantages is only there when I am not driving it.:cheers:

otto Collaborator

otto

Posted
Posted

Dont know if this is relevant but i got told a turbo turns heat energy into mech energy. i would have thaught a manifold that kept the turbo as close to the action (exaust valves) as possible (without affecting flow to much) would be better/more efficient, the highmounts i have seen seem to keep the turbo alot further away than the lowmount.

Sumo Mentor

Sumo

Posted
Posted

A turbo works on a flow energy afaik. Heat alone with not spin a turbine.... my understanding is very simple, but the spinning motion caused by the exhaust gases spins the common shaft that has a compressor at the other end.

Cheers

Sumo

lwells Grand Master

lwells

Posted
Posted
A well engineered low mount doesn't present much more of an access problem, don't get trapped into comparing a aftermarket high mount with the factory low mount.  You really need to compare it to an aftemarket low mount.

Any tips on improving upon the stock lowmount setup for those of us who don't want to go for a highmount? :cheers: Is it just a question of trying to smooth out the airflow through the manifolds, or should they be replaced entirely, etc etc etc?

Lucien.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

the thing is you cant have a BIG turbo low mounted easily.

Depending on what car etc etc.

But i have all of 3-5mm, yes MM clearance in some areas, there is no "better" way to have designed it as low-mount/stealth is gonna be tight when you gotta fit a turbo and a big eXT gate in there somewhere, combine that with a exhaust dump pipe...

If it was something smaller than a GT30 then yeah, easily.

lwells Grand Master

lwells

Posted
Posted
I havent see too many aftermarket low mounts..the only one that i woudl like to use is the factory GTS-R or the cast HKS jobs.

The Silk Road ones seem to be on Yahoo JP all the time, but I haven't heard any reports of people using them...?

LW.

Sydneykid Grand Master

Sydneykid

Posted
Posted
the thing is you cant have a BIG turbo low mounted easily.

Depending on what car etc etc.

But i have all of 3-5mm, yes MM clearance in some areas, there is no "better" way to have designed it as low-mount/stealth is gonna be tight when you gotta fit a turbo and a big eXT gate in there somewhere, combine that with a exhaust dump pipe...

If it was something smaller than a GT30 then yeah, easily.

We tried a GT30 on the R34GTT mounted to the standard manifold using an adaptor. It fitted in easily. If I remember rightly, Steve on here also had the same on an R33GTST making 300+rwkw. The HPI R34GTT had a GT3040 low mounted on a Croydon's custom exhaust manifold, around 310 rwkw if I recall correctly.:rofl:

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      R32 GTR - Where to begin

      By Duncan · Posted

      You're 20 years too late mate. Used to be 80% skylines back in team trackday days
    • GTSBoy
      R32 GTR - Where to begin

      By GTSBoy · Posted

      There's a lot of drug money on that side of Sydney. Just sayin'.
    • Dose Pipe Sutututu
      R32 GTR - Where to begin

      By Dose Pipe Sutututu · Posted

      At SMSP, I mainly see Hondas, M cars, A90 Supras and of course, plenty of Evos. Have not seen a single R32 ro R34 Skyline on the night sessions that I've been to. That's really saying something.
    • V35_Paul
      Looking at getting a Tesla style Screen for my V37 Skyline.

      By V35_Paul · Posted

      I like mine. Much better than stock. Like i said before the reverse/parking cameras look even worse than normal, still useable. When you buy one make sure it's the latest version. Heaps of cheap ones that run the old hardware and software. Got mine from AliExpress. Mine is quick no lag, boots up 1-2 sec. Menu is fast. Netflix is fine and so is YouTube. Android Auto is random taking 3sec to 15sec. Most of the time it's quick. Very rare it doesn't connect. But that could be a phone thing.   Now I think they use a Pixel 3XL to run this whole thing which i guess is fine, but the problem is that some apps will not work on old hardware like Disney Plus  Maybe Prime Video too 🤔. they will not update. Iv'e tried getting the APK Disney + but i still couldn't get it working. I have a Data sim installed so i have internet all the time. You can't Hotspot off your phone and connect Android Auto at the same time. Not that you need too, if you want you can hotspot off your phone and run any internet map app (google maps) and you can run the Spotify app on it's own (the app runs better than android auto) You can still access the INFINITI intouch system for all the o.g stuff    P.S i got new non Polarization Sunglasses too 😎 
    • Kinkstaah
      R32 GTR - Where to begin

      By Kinkstaah · Posted

      I also don't mean to rain on your parade. But with a 5-10k budget for road only? I'd want to check confirmation that everything IS working correctly and I'm with @GTSBoy for a plan of action here. I'd be checking subframes, bushes, exhaust hangers, interior bits and generally QOL things and CONFIRMING they are working right before thinking about motor. You can get 250KW+ on stock RB26 hardware by simply removing the built in restrictors and tuning the stock ECU. If you want purity that's as far to take it, which I would be worried to do and won't think the budget would allow for when earnestly checking for 30+ year old car stuff.
×
×
  • Create New...