Plazmaman Plenum On Rb25Det Neo

[SargeRX8]

All that time, effort and money for 0 gains? ZERO GAINS? MADNESS. I'm going to be swapping ECU's soon, from PFC to something with a map sensor. No power gains directly but I do have the option to get E85 up in this bitch.

[Hanaldo]

Could say the same for paying 4k for Jap brand wheels.

It is a lot of money. But I do want to go down the forward facing path, and the Plazmaman so far seems like the least dicking around to get fitted. I'll be honest, it is mostly about appearances. I don't like the stock cross over pipe or the intercooler plumbing and I'm done with spark plug changes being a 45 minute job.

I don't care about adding numbers to my power figure, my main interest is not losing torque in the mid-range. If there's a better option then I'm all ears, I haven't paid for anything yet.

All that time, effort and money for 0 gains? ZERO GAINS? MADNESS. I'm going to be swapping ECU's soon, from PFC to something with a map sensor. No power gains directly but I do have the option to get E85 up in this bitch.

Easy enough over on the east coast I imagine, but in WA E85 isn't really an option yet. I'm not keen on paying $600 odd dollars to buy a 200l drum that I have no room to store anywhere. The appeal of changing ECU's for the possibility of running E85 was lost when I got the $3500 quote to do so. When I get word that E85 has officially been made legal to sell at the pump here then I'll put it back on the priority list.

Edited February 6, 2012 by Hanaldo

[dori34]

i reckon you will lose torque/response by going FFP.

i'm sure some others will be able to confirm this.

[SargeRX8]

http://www.skylinesaustralia.com/forums/topic/363467-rb25-det-intake-manifold/

[Hanaldo]

I've seen mixed results to be sure. But the general consensus that I have found in threads on here is that my best option (aside from staying stock obviously) to limit any losses from going forward facing is to use as close to the stock runner length as I can. The Greddy plenums and their copies change to shorter runners, and I've seen people claiming more power up top with losses through the middle. I've also seen people claiming losses across the whole rev-range and some who say there is no difference at all. Same goes for the Plazmaman.

I'm not happy with the stock plenum, that's the situation. I don't want to stay stock so that's a non-issue. The issue is which plenum I change to. Is the Plazmaman my best option for maintaining as close to stock performance as possible, despite the extra cost, or is there a better option? If there's a better option then please fill me in.

Edited February 6, 2012 by Hanaldo

[boostn0199]

From what ive read about feedback from the various plenums over the years If I was going one I would go the plazaman as they have longer runners then the greddy. I dont think youll have any problems going the plazaman youll also gain abit of response since your considerably shorten your cooler pipe. Post up back to back results when your done.

[SargeRX8]

Get a bigger turbo to compensate for the larger plenum. Or if you really want to spend some money, get the GTR plenum mated onto your neo head: http://www.skylinesaustralia.com/forums/topic/247435-mating-rb26dett-throttle-plenum-on-rb25det-neo-head/page__st__40

[Hanaldo]

Get a bigger turbo to compensate for the larger plenum. Or if you really want to spend some money, get the GTR plenum mated onto your neo head: http://www.skylinesa...ad/page__st__40

The turbo I have should be enough compensation.

Also, come on... Have you even read that thread?

the stud patterns don't match up.

Adapter plates can be found or manufactured to mate the 26 intake manifold to a 25 head. Blitz offered one for over $1K. Steep, and no longer available. Also, moving the plenum away from the head creates other issues.

Thinking outside the box, the old man decided to modify the head and eliminate the need for an adaptor plate to suit the 26 stud pattern. This involves plugging some of the holes and building-up areas on the intake side through TIG welding, followed by drilling and threading new holes to suit the RB26 plenum.

just remember you need to use the rb25 ACC value, as it has 2 plugs on it and the gtr one only has 1.

you also need to mod the throttle cable, use gtr fuel rail + injectors, wire in a gtr resistance pack and get gtr injector plugs.

Also you need to mod the water outlet on the gtr plenum as it hits the VVT; best way to do this it remove the water outlet on the rb25 plenum (just cut it off) and weld it onto the gtr plenum.

This is the conclusion:

looks like a f**kload of effort so far, congrats dude!

Don't get me wrong, I take my hat off to Cris and his dad for undertaking and completing that so well. But I have neither the skill or the time that is required for that. I can do basics, I can't start welding and machining the head, nor do all the necessary modifications to the plenum. For me to do that would end up costing countless times more than the Plazmaman as I wouldn't be able to do any of it myself. Spending money is the means, not the objective.

Edited February 6, 2012 by Hanaldo

[kitto]

So much money and stuffing around for no gains.

Nissan designed it well, so stick with it.

You'll lose mid range torque and spend a lot of money and piss about for no major reason.

If you really want a forward facing plenum, fit a GTR unit as said earlier.

Although, i'm almost positive if Nissan was easily able to fit a flip up plenum and retain the ITB's on the RB26, i'm sure they would have.

The forward facing plenum may increase response yes, but for a cost of torque.

I know several people who have regretted going down this path.

[KiwiRS4T]

I put on a Greddy copy (cost $300) with my stock throttle body when I got my RB30 so no direct before and after comparisons but I am happy with the way my car goes. The main downside, and it appears to apply to the Plazmaman as well, is that the angle of the intake means your piping has to go where the battery is and I had to hack away some of the fusebox to make room for the throttlebody.

I believe some people are developing adaptor plates to make it easier to fit RB26 plenums although if I had more money I would just have put an RB26 head on my RB30.

[Hanaldo]

So much money and stuffing around for no gains.

Nissan designed it well, so stick with it.

You'll lose mid range torque and spend a lot of money and piss about for no major reason.

If you really want a forward facing plenum, fit a GTR unit as said earlier.

Although, i'm almost positive if Nissan was easily able to fit a flip up plenum and retain the ITB's on the RB26, i'm sure they would have.

The forward facing plenum may increase response yes, but for a cost of torque.

I know several people who have regretted going down this path.

And I know LOTS who couldn't be happier having gone down this path. Is any of what is being posted in here actually first hand experience, or is this all regurgitated 'he said she said' information? I'm not about to invest 1.5k into something without doing research, and as yet I haven't really come across anything where the result was SO much worse than the stock intake manifold that the owner regretted the change. There's Roy's experience with it, that's about the only direct poor experience I can find. Trent from Status has mentioned that he has seen no gains, but what sort of losses have you seen Trent?

On the other hand, Mercury Motorsport claim to have done testing on the Plazmamans and rave about their performance:

I have this conversation with many customers and we have tested both back to back to determine the pros and cons. The main difference is that the Plazmaman retains the standard runners, where the Greddy has shorter runners incorperated into the unit. This design feature of the Greddy in simple terms, creates more top end power at the expense of mid range torque. The longer factory runners helps bring boost on at an earlier rpm (have seen 300-500rpm better spool!!!) so if you want your turbo to spool faster, make more useable mid range power/torque but miss out on a little bit of peak hp, then the Plazmaman is for you. If you only care about the number on the dyno, get the Greddy.

You also suggest going to the RB26 intake, but can you please point me in the direction of the results that show it is worth the cost and hassle? There is no doubt that trying to fit the 26 intake to my car would cost a HELL of a lot more than the Plazmaman or any other option I have, not too mention the fabrication and effort that it requires as well. I haven't seen any results that tell me it is THAT much better either.

Look my car isn't a serious race car. It's a bit of fun, and I do track it and I like to go quick. I also like it looking good, I've spent money on other areas than performance purely for the looks perspective. To anyone who has actually done it, does changing to a forward facing plenum REALLY ruin the car? Does it make such a big difference either positive or negative that it simply isn't fun? Just to be clear, I'm not putting this on a stock setup either. I am currently making 393.7rwhp (hub dyno, debate it if you will) with plenty of torque.

Please, experience tells all, so if someone has done this and it did work/didn't work, link me.

I put on a Greddy copy (cost $300) with my stock throttle body when I got my RB30 so no direct before and after comparisons but I am happy with the way my car goes. The main downside, and it appears to apply to the Plazmaman as well, is that the angle of the intake means your piping has to go where the battery is and I had to hack away some of the fusebox to make room for the throttlebody.

I believe some people are developing adaptor plates to make it easier to fit RB26 plenums although if I had more money I would just have put an RB26 head on my RB30.

It's possible to route the piping through the side, just requires a couple more bends. Depends how fussed you are whether you deem it worth it or not.

Edited February 6, 2012 by Hanaldo

[Aggroman]

ok after reading this ill make a few points from first hand experience.. Plazmaman did the install of the plenum but everything else I did on the car

Your injectors will fit (I installed ID1000's and had a good amount of room and could pull the rail off with ease so 10mm spacer is shitall), you will need to do either what dahtone said or just get a new FPR. Id suggest the sard one and standard rail adaptor for about 200-250ish if you shop around or go the turbosmart version and mount it on the strut tower underneath (possible headf**k to adjust?)

Torque difference depends on who tunes it and if they did a good job of it or not, it may drop a little but honestly not enough for me to care (hks version of a 3076r turbo int gate, lowmount as a reference).. Throttle response will be better but i cant recall it being a great deal

You can get custom piping made up to suit the hole you already have BUT it may look shit with tight bends (you can debate the KW and response loss from it but blah) it will also cost decent money as most places charge by the bend.

I think that covers all of it?

[Hanaldo]

Thanks David, I appreciate the response.

Is ditching the fuel dampener ok? I'd rather not if it's going to cause problems... But if it's one of those things that just doesn't make a difference once you start modifying things like the fuel pump etc. then I'll just do what Dahtone said.

[dori34]

i got my custom plenum from CPC, which used half of the bottom runners (cut and shut) to mate up to the plenum.

the only downside is he doesnt make fittings/holes for the IAC valve so it had to be remotely mounted.

If i went through it again, i would go a greddy or plazaman or even stick with stock.

i have no direct comparison but i reckon i have lost some low down/mid range as i can feel it boggy down low.

i wanted the cooler piping to run through the original hole as well but it would be too much bends and may cause issues with air flow rather than a straight pipe.

i used the stock fuel rail, nismo reg and injectors, and the dampener stays.

[Aggroman]

Thanks David, I appreciate the response.

Is ditching the fuel dampener ok? I'd rather not if it's going to cause problems... But if it's one of those things that just doesn't make a difference once you start modifying things like the fuel pump etc. then I'll just do what Dahtone said.

Couldnt tell you to be honest, Try asking plazmaman what they do about it? if they just remove it and all those cars running their plenums go fine I would say that its safe to do so.

[joeyjoejoejuniorshabadoo]

Couldnt tell you to be honest, Try asking plazmaman what they do about it? if they just remove it and all those cars running their plenums go fine I would say that its safe to do so.

which is a gain

[methz]

Ive seen a few rb25s with these plenums fitted and im not a fan at all.

greddy inlet anyday over these ugly big heaps of junk lol.

[Hanaldo]

i got my custom plenum from CPC, which used half of the bottom runners (cut and shut) to mate up to the plenum.

the only downside is he doesnt make fittings/holes for the IAC valve so it had to be remotely mounted.

If i went through it again, i would go a greddy or plazaman or even stick with stock.

i have no direct comparison but i reckon i have lost some low down/mid range as i can feel it boggy down low.

i wanted the cooler piping to run through the original hole as well but it would be too much bends and may cause issues with air flow rather than a straight pipe.

i used the stock fuel rail, nismo reg and injectors, and the dampener stays.

Thanks mate. I was considering a CPC as well having read Ariel's thread, but unfortunately he would need me to send him my runners so he could get started, which means a lot of down time for the car.

So you managed to get the dampener to fit with the Nismo reg? Maybe I should just get a fuel reg, I suppose I'm gonna have to bite the bullet at some stage. I don't have much choice with regard to the intercooler plumbing, I've got a custom oil catch can/rad overflow unit sitting in the battery tray with no room for it to move over.

Couldnt tell you to be honest, Try asking plazmaman what they do about it? if they just remove it and all those cars running their plenums go fine I would say that its safe to do so.

If I could get in contact with someone there who actually knows what they are talking about then I'd give it a go, but so far whoever I've spoken to would tell me anything to get a sale. To be honest, it doesn't inspire me with confidence about dealing with them.

Ive seen a few rb25s with these plenums fitted and im not a fan at all.

greddy inlet anyday over these ugly big heaps of junk lol.

Come on, not even Phil's?

Each to their own man; but either way, both Greddy and Plazmaman look miles better than stock

I am in two minds about whether to get it mirror polished or satin black. It seems a shame to get a Plazmaman in anything other than mirror polished, but to be honest I think it may be too much chrome for me. Still not sure.

[34GeeTeeTee]

More examples for ya -

Ians R34 by JEM -

My R34 soon to be by JEM -

Random pics sent to me by Plazmaman -

With my setup i am going to use a small battery that i have found fits the standard battery cables and sits sideways right next to the cooler pipe, this means i can retain my washer bottle location and be lazy and avoid having to put the battery in the boot.

I had long conversations with Plazmaman about the plenum setup etc and combined with the 6Boost gear etc it should be a responsive and fun all round package... I dont care about dyno numbers, i can about having a fun all round car to drive..... And the look of the factory setup is FAILtown -

Enough spamming up your thread now...BYE

[2rismo]

IAC valves can easily be replaced by a competent tuner. My Plazmaman plenum allowed me to run the stock RB25 IAC (upside down / had to extend two wires) but I ended up pissing it off and replacing it with a piece of flat steel, some silicon and the bolts that normally hold the IAC in place.