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RB25DET Intake Plenum change


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specs-

-6 ltrs vloume

-accepts XF t/b

-fully TIG welded

-tuned length ram tubes

theres a guy thats got one and also got a nizpro he had them flow tested and the nizpro read 204cfm, and that one read 223cfm, only thing the custom one had a 85mm t/b and nizpro 65mm so they would be very close.

Originally posted by Gradenko

GTS-t VSPEC, do you know where your friend got his cut'n'shut done or if he had it tested for even flow? I'd be interested in pics (or seeing it in person). I'm in the process of doing something similar, so first hand feedback would be great.

I don't think is was flow tested, but it has been on Barries Dyno and achieved excellent results. Alot more people are starting to go this route. I don't have any pics, but a friend of mine is making a custom plenum and I'll post some pics of that soon.

See'ya:burnout:

Guest MFX_R33

I can't really comment on the difference the plenum made by itself cause I got the front mount, plenum, throttle body, and EMS all in one hit. To be honest though I don't think the plenum makes much difference at this power level. I like the fact that it cut's down on I/C pipework which is the main reason I got it (and the fact that my car is a show car and it looks good).

Jeff.

Originally posted by russcb007

Also I have simply wrapped my intake from plenum to intercooler outlet in insulation and the heat soak was measurably different. (Looks dodgy but...) Even before I put the thermometer on it the pipe stays cold with the insultion but without it is quite hot to touch.  Cheap way to earn a few measly Kw.  Has anyone else done this...I thought it was a pretty cheap obvious thing to try.

Does someone have the contact details for where sub zero intakes are sold.

Cheers,

Russ

Do you have any pics of the wrapping. Would be interested too see how you have done it.

Subzero are on the Gold Coast QLD. Brisbane road i thikn. if you cant find the website, u will find them in the white pages.

Originally posted by Steve

All this for $895 fitted, and for an extra $200 will fit an 80mm throttle body.  This has to be close to the bargain of the century - I'm getting one!

Thanks for pointing Hills motorsport out - saved me hundreds

Hmm, is that $900 inclusive of cutting a hole in the chassis, running the extra intercooler plumbing, re-locating the bov, supplying a new throttle cable (the old one is too short), etc? Because I got quoted around $600 in labour alone to fit my own custom plenum on including all of the above. Is he only selling his own for $300, or does Mark just not like me? ;)

  • 2 weeks later...

JimX,

That is what they quoted, to tell the truth I wasnt too concerned about the details of fitting as I was after one to be sent to me, which is happening.

They do supply a throttle cable, and if you want one sent to you, rather than fitted, they are doing one for me for $890 with throttle body.

I think $600 is a bit rich for fitting a plenum - I say this because it cost me about that to get my cooler fitted, including all the pipework being made up.

These plenums bolt up to the stock runners.

Anybody else been quoted to fit a plenum or tell us how much to fit a plenum? Anybody else think $600 is a bit rich?

It looks like I had a bitch of an intercooler setup, because I asked how much extra it would be to fit a new intercooler at the same time and I will end up saving around $100 off the original quote! (add to that the cost of the intercooler of course)

Where my current outlet is is very awkward and he said that routing the piping for it was where most of the cost was going. So it should be around $500 to fit the plenum and cooler inclusive of parts, which seems reasonable to me.

I am just in the process of installing my fmic (600x300x75).

I bought a plenum of a mate that had had it modified (he got a GREDDY item), they basically just did the cut'n'shut so it feeds from the front. This is the plan of attack

1) Buy wanky BOV (already done for $200)

2) Install FMIC (already done, FMIC cost $1100 with brackets welded on it, I had to remove front bumper and cut some steel out of the front along with shaving a fair bit of plastic of the rear of the bumper. Not Hard)

3) Get modified plenum (already done cost around $300)

4) Pull front bumper off again and cut a hole in the front driver side panel for outlet of FMIC to feed plenum.

5) Take car around to bloke who welds Stainless. He is going to weld 2 stainless pipes. The first simply goes from the inlet of the standard FMIC (no need to repipe that section) to the inlet of new FMIC. Second pipe will go from outlet of FMIC through the hole i am cutting to the inlet of the plenum, he will also plumb in my new wanky BOV. (i am told this should cost aound $200 to $300 parts included)

6) Take the pipes, plenum and car to my regular mechanic. Get him to get the throttle cable extended at a local motor bike shop, also connect the pipes up and tune it. (Again this i have been told will cost around $300 - $400 since PowerFC settings have to be changed).

In short get the parts and organise / do it yourself. There is a lot more satisfaction in it.

Oh and for a modified plenum go spend the extra cash and get it from Hills. I talked to him about it and it really sound like he did his homework.....

I paid about $1500 for mine, then you'll need a different throttle body, the Infiniti one is probably the best. Most decent tuning shops should be able to get it, but look into some of the local ones, they are very well designed:D

See'ya:burnout:

paul was that $1500 fitted? including injectors, fuel rail etc....?

adrian :P

is it worth putting new plenum on automatic gts-t? or just stay with normal plenum?

say i wanted to bolt a bigger turbo later on? like gt30 or wateva i would have to go to a new plenum then right? so the turbo can be mounted?

adrian :D

A new plenum obviously has to come along with a front-mount intercooler. If you also have the exhaust done, I would say the plenum is definitely worthwhile doing. If nothing else it will improve your throttle response, and in theory should be good for at least 10-20kw.

For a mild car the cut-n-shut option is probably going to be the best value, you can't really get the most out of the expensive ones until you start going wild with the mods.

Adrian,

Currently using the stock fuel rail and injectors, but plenty of room for a top feed rail:D

We are talking about intake manifold, turbo's are on the exhaust manifold, so it doesn't make a difference to turbo choice.

See'ya:burnout:

nah nah paul i worded the post wrongly!

i meant like say u wanted a high mount turbo right you would have to change over to to a new plenum hey coz the old plenum will be blocking the way with all the intercooler piping?

adrian :)

i am seriously considering this for the show coz u know how i am also after big power! :D

  • 1 month later...

bringing thread back to life.

out of interest how did that cut and shut plenum go.

i know u'd like to sell it. but it do the job. i am getting one made up. the angle that redirected path the air takes, can that cause adverse effects.

not providing air to right cylinders etc.

heard people say it starves 1st cylinder, but you know what people say, without any proof and all.

just curious.

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