Plenum chamber

[two40]

I'm in the deep end when it comes to lots of things regarding this brilliant invention called a car. So take it easy with me and explain things like you would to an ametuer. Although don't hold anything back as I want to learn as much as I can.

I've heard that a professional custom built plenum can yield increases in performance in a n/a car simmilar to those of bolting on a turbo. My source said that this would not happen all the time but it does happen. If this is the case, how would a custom built plenum increase the performance of a turbo. Is this a common mod? How much would it roughly cost? etc etc

I just want to pick your brains on everything that has to do with it. How does it work, what parts are directly related to its performance or lack of it.

You get my drift.

[meggala]

A custom plenium or one built for performance. can make power on a turbo cause the manufacturer build the standard one to price more than for maximum perfromance execpt in the case of the gtr where they considered performance with price playing a smaller. piece.

the custom or aftermarket plenium has the advantage that the air does not have to travel as far also the amount of air that the plenium can hold is larger meaning more can get forced in. the flow of the air inside the plenium can be better controled.

so the air is cooler the air has better flow and there is more of it. and it generally has a shorter run from the turbo to the custom plenium than stardard. so the bang in the motor is bigger and produces more power.

My personal opinion is that the plenium should be done later rather than earlier in the mod process as there is more power to be gained for less money doing other things.

cheers

meggala

[two40]

the custom or aftermarket plenium has the advantage that the air does not have to travel as far... meggala[/quote:1e43e4905c]

So meggala, that means that all this piping going around the engine (below) will be considerably shortened therefore air intake will be more efficient. This also means that the throttle body has to be moved. What else has to be moved along with it?

With a custom plenum on a GTS25T would the runners also be shortened or would you keep the factory ones? In other words, does the plenum unbolt from the runners or do you have to get these made as well?

The flow of air in a turbocharged car is as follows. (as far as I can tell)

Air Filter-plumbing-Turbo-plumbing-intercooler-plumbing-Throttle Body-Plenum Chamber-Intake Runners

Is this correct?

Can someone finish this to the point of muffler?

If I'm asking for too much tell me to shut up.

[img:1e43e4905c]http://communities.ninemsn.com.au/GTS25TSkylinePics/modsstage2.msnw?action=ShowPhoto&PhotoID=33/[/img:1e43e4905c]

[two40]

If the image doesn't load up follow this link.

[meggala]

ok Ihad a look at the pics of your car . yes there will be some loss from using this type of setup. but the cost of the plenium will not be justified for the gains. there are plenty of 12 second cars running this setup so dont stress if your horse power goals are to run 11's or quicker the plenium is important.Is the rest of the car stock or do you have a different turbo .let us know your setup.

cheers

meggala

[two40]

I've pretty much reached the limit of the stock turbo. At the moment it's holding everything back.

There's a turbo back mandrel bent exhaust, a 4" FMIC, Apexi PFC, Blitz boost control & fuel pump among other things. For a more detailed list follow this link.

My next step is to get a bigger turbo. I'm thinking a HKS 2540 but as this is $$$ I might get a T4. I've seen a setup where the turbo comes on at 2500rpm. It was pretty impressive.

What kind of a gain would you get from an external wastegate? I haven't made my mind up about ext/int yet.

At the same time I might have to get injectors. Either 555 or 700's, depending on $.

After all this it might be plausable to get a plenum made up. What do you think?

[meggala]

you have it pretty sussed as to what you want when selecting the turbo you are best to set your self a power goal 500 600 700 etc then talk to some one who really knows there stuff and run through the options the hks 2540 is wicked but so are there biggerones like 2835 an 3037 etc. I reckon lag is a good thing cause you can toodle around doing the shopping peak hour traffic and never come on boost but when you want it you just stand on it and its there. just my opinion.

interal is easier external will give you better boost controll .

meggala

[Ethan_R32]

I've pretty much reached the limit of the stock turbo. At the moment it's holding everything back.

There's a turbo back mandrel bent exhaust, a 4" FMIC, Apexi PFC, Blitz boost control & fuel pump among other things. For a more detailed list follow this link.

My next step is to get a bigger turbo. I'm thinking a HKS 2540 but as this is $$$ I might get a T4. I've seen a setup where the turbo comes on at 2500rpm. It was pretty impressive.

What kind of a gain would you get from an external wastegate? I haven't made my mind up about ext/int yet.

At the same time I might have to get injectors. Either 555 or 700's, depending on $.

After all this it might be plausable to get a plenum made up. What do you think?[/quote:cde590b1e2]

G'day onarun,

I have pretty much the same mods as you except power fc (i have S-AFC for now) and the oil cooler.

I too am looking at upgrading the turbo, and ive had a look at HKS gt2530, 2540 T3/T4 and garret GT30. Im still not sure on which one to go, and whether external/internal wastegate.

I dont think you need to worry about the plenum yet, only when you get over 500hp id reckon you would need a custom one.

[two40]

I just spoke to my mechanic and he said pretty much the same thing. I wasn't planning on getting one before the turbo, but I still wanted to suss them out.

Ethan,

What's the best price you've been quoted for a 2540 without labour? Do you have to mod/replace the manifold for a 2540? I'd preffer this turbo to the others as you can boost it a bit more. Let me know how you go with your mods.

[Ethan_R32]

Onarun:

for a HKS GT2540 ive been quoted around $1600 without fitting. And this bolts on to original manifold and is ball bearing.

Do you know what is the max. horsepower this turbo can handle, and its psi efficiency range?

Andrew

[two40]

Ethan, that's a damned good price mate. I'm gona call BD4's here in Sydney tomorrow and get some prices. They are HKS distributors but I'm betting my life that they will quote me upwards of $2500.

I remember reading somewhere that the 2540 is rated at around 350hp. Don't quote me on this. I think it might be a bit higher. Not sure how much you can boost them but it'll be considerably higher than it's Garett counterpart.

[meggala]

the 2540's are at least 400 hp probably 450 and their main operating range in 1.2 bar. but I got that from a mag so who knows

try this its a car for sale with =one

http://www.japimportcar.com/en/classifieds...ds/show.asp?118

only 200rwkw yeah only :-)

but I think both of you want more any way.

meggala

[two40]

mmm, I thought I was wrong. 350 did sound a bit too low. Must have read 450 but just forgot. Thanks meggala.

[Ethan_R32]

ONARUN:

yeah get a price from BD4's and post it here. The price i got was from the guy who complianced my car in melbourne. He gets parts striaght from Japan, even HKS themselves!!

I think that with a 2540 and only at 1bar you should be getting 220rwkw. Matt (whatsisname) from SDU forums only runs about 12-13psi and has 220rwkw if i remember correctly, with a T3/T4 turbo

Ive also replied to your PM onarun.

[two40]

Ethan,

BD4's quoted me a 2540 kit for $4300 and a 2835 kit for around the same price. Since the 2540's bolt straight on it would be a smart choice. Tim also told me that the 2835's don't come in external wastegate form but I'm sure I've read somewhere that they do. Can anyone clear this up for me?

[Squizz]

I heard somewhere that having a spacer on your plenum/intake manifold can yeild some performance gains, is there any fact in this? The reason I ask is I am soon to be in a good position to try this...

[Squizz]

anyone?

[Squizz]

c'mon someones gotta know...

[Squizz]

stop ignoring me or I'll cry...