Greddy Plenum Spacer Info (Torque/midrange)

[WARLORD]

i don't often comment on here that much due to the completed bullshit i read sometimes but this is what i think.

what kind of loss did you have in the mid range ?

what top mount manifold to you have ?

who tuned the car.? (that's a big thing ive had self proclaimed experts and real experts tune the car)

in my old set up i had a greddy plenum only difference is i have a q45 throttle body and a stock exhaust manifold hks 3037 pros turbo and the mid range was great 312kw at the wheels and with 700+nm full boost by 3200rpm.

i don't think a spacer in real world conditions is going to do a thing.

my new set up has a hks low mount and larger turbo and the mid range is neck snapping.

I think you need to look at the entire setup.

plazmaman plenum are better but again its the hole package.

most of my build has been trail and error and shuffling past the bullshit you read on the internet.

​and inlet temperature is better controlled if your that concerned with water meth as i have done.

Edited January 19, 2015 by WARLORD

[skylineking]

i don't often comment on here that much due to the completed bullshit i read sometimes but this is what i think.

what kind of loss did you have in the mid range ?

what top mount manifold to you have ?

who tuned the car.? (that's a big thing ive had self proclaimed experts and real experts tune the car)

in my old set up i had a greddy plenum only difference is i have a q45 throttle body and a stock exhaust manifold hks 3037 pros turbo and the mid range was great 312kw at the wheels and with 700+nm full boost by 3200rpm.

i don't think a spacer in real world conditions is going to do a thing.

my new set up has a hks low mount and larger turbo and the mid range is neck snapping.

I think you need to look at the entire setup.

plazmaman plenum are better but again its the hole package.

most of my build has been trail and error and shuffling past the bullshit you read on the internet.

​and inlet temperature is better controlled if your that concerned with water meth as i have done.

Hey mate thanks a lot for commenting & I know what u mean with everything your saying! My question is when keeping all the variables the same except for either the plenum or a spacer with the existing plenum what would the results be....

The setup I had was very similar to yours 3037pro s greddy plenum with q45 throttle body pon cams & a rare HKS GTII top mount manifold external gate. With a .87 housing (weird hks sizing) on 21-22psi I was making 330rwkw on e85 but full boost 4th gear on the dyno wasn't til after 4000rpm maybe around 4200..... When I had a .72 housing & 98 unleaded it was making 310rwkw on similar boost & similar response. My ecu is a power fc.... I have personally always wondered if mechanics are giving ur car the best effort they possibly can...... I'm not an expert so I don't know, a lot has been trial & error & I've had some misleading info in my time thats why i try tread carefully cause I've spent a lot of money on my car. If my car was making full boost around 3500 I would be ridiculously happy...... Don't know why people with 3076r/3037s are making boost earlier than me I just wonder if we are comparing figures correctly ??

Really want to learn how to tune so I can start doing it on my car then moving on to friends cars too!

Cheers for the input anything more u got mate is appreciated

[skylineking]

I use a phenolic intake gasket on the inlet manfold for my RB25DET. My inlet plenum uses the standard lower runners with a MX Performance plenum top (similar to a Plazmaman manifold).

I don't beleive the intake temp changes would be very significant, as the coolant runs through the inlet manifold. This will heat up the inlet manifold to what ever temperature the coolant is at. Conversly if you were running a standard gasket, the plenum may be a touch warmer, but the coolant will then do the opposite and try to bring the temperature of the inlet manifold down to the level of the coolant. So there's probably only a few degrees in it either way.

I would have preferred to use a phenolic gasket between the lower runners and the plenum top (provided it could seal correctly) however I wasn't able to find anyone who makes them.

Awesome to hear from someone who used a phenolic gasket!! I have 1 question though, if the temps were similar while it was running due to the coolant, is it the same when u switched the car off, as in did the inlet manifold cool quicker than usual (could u touch the plenum within a few minutes without it almost burning u) or is the coolant still causing heat to be retained...?

[BlackBox]

I can't recall having coolant flowing through my plazmaman manifold? Unless you are referring to iac

[skylineking]

I can't recall having coolant flowing through my plazmaman manifold? Unless you are referring to iac

Yeah sorry mate didn't get a chance to re-read or edit my post had to head off quickly cheers for clearing that up. Personally I think IAC won't make much difference as far as the temps go cause the coolant flow into it is minimal but was wondering if the person who used the phenolic spacer could comment further ?

[Ryno]

I can't recall having coolant flowing through my plazmaman manifold? Unless you are referring to iac

This is the setup I use.....

As with any RB25DET plenum setup you will see that the coolant exits the block/head through the large orifice on the lower runners of the plenum. As a result the coolant will heat the lower runners and plenum top (plasmaman or otherwise) through conduction. As I said in my earlier post, if the phenolic gasket went between the lower runners and the plenum top you could keep the plenum top cool, but unfortunately the only phenolic gasket I could find goes between the head and the runners, therefore the performance gain would be minimal in my opinion.

[skylineking]

This is the setup I use.....

As with any RB25DET plenum setup you will see that the coolant exits the block/head through the large orifice on the lower runners of the plenum. As a result the coolant will heat the lower runners and plenum top (plasmaman or otherwise) through conduction. As I said in my earlier post, if the phenolic gasket went between the lower runners and the plenum top you could keep the plenum top cool, but unfortunately the only phenolic gasket I could find goes between the head and the runners, therefore the performance gain would be minimal in my opinion.

Thanks again for the great post mate, Yeh I know what u mean, we were referring to the top half of the plenum not having coolant through it.

I guess the only gain is from having the phenolic spacer is that the head itself is not in direct contact with the lower runners so therefore some heat should be lost but the coolant flow still will cause some heat gain! No biggie though ? I think they won't be a bad thing in any case! I'll fitting one to mine so I'll see how it works out!

[Scott Black]

Really want to learn how to tune so I can start doing it on my car then moving on to friends cars too!

http://www.amazon.com/Designing-High-Performance-Injection-Systems-Publisher/dp/B004XINOJO

we used this book in the course on dyno tuning i did, has alot of information that will give you a good understanding on tuning

[skylineking]

http://www.amazon.com/Designing-High-Performance-Injection-Systems-Publisher/dp/B004XINOJO

we used this book in the course on dyno tuning i did, has alot of information that will give you a good understanding on tuning

Thanks for that mate you're a champion! I'm ordering a copy now! ??

[RBceffy25]

This is my experience with plenums etc....

My Old RB25 with standard Intake plenum, fmic, turbo back 3in ex, elec. boost control, PFC, standard turbo was good, nice and responsive with good low end pull.

My brothers RB25 with Greddy copy plenum, fmic, turbo back 3in ex, elec. boost control, PFC, standard turbo/then NEO turbo was fantastic, even more boost responsive and felt like it had even more pull.

So, front facing plenum with all it associated factors - less pipework etc. - was a noticeable improvement on boost response, which I feel negated any potential loss in torque.

It then went to GTR plenum and itb's, fmic, turbo back 3in ex, elec. boost control, PFC, HKS GTRS and poncams and four degrees of ex cam retard on PULP which was amazing. The snappy response from both turbo and throttle was amazing. The seat of the pants feel was fantastic. As soon as you touched the throttle it was so angry and torquey with a tiny bit of lag over the previous setups, obviously due to the larger turbo.

Then, identical setup but with E85. Same response with more overall power, of course.

With this setup it made 110rwhp and 7psi at 3k then 175rwhp and 12.5 at 3.5k

Then, in the quest for ever more response, we setup a home made smoke machine test to find any and all boost leaks, which the were several tiny ones all over the place.

The previous setup was retained - GTR plenum and itb's, fmic, turbo back 3in ex, elec. boost control, PFC, HKS GTRS and poncams, ex cam back to zero and no boost leaks. The result is incredible. It made a couple HP less peak - I think due to the cam timing change - but gained response, power and torque pretty much everywhere else. It now makes 140rwhp and 10psi at 3k then 240rwhp and 19psi at 3.5k which in real word terms feel absolutely incredible on the road.

In my experience, I honestly think the gains outweigh and overshadow any loss as far as plenums go. But, as WARLORD said, its definitely down to the entire setup. The sum of all the parts and attention to fine details make the whole. So, I think front facing plenums are a good thing provided the rest of the setup is in good order and refined.

I cant say enough good about the GTR ITB setup. I dont think it lost anything anywhere (torque,power) but then we never compared that exact setup with standard runners/plenum etc. The itb's really made the car feel soooo so responsive and just angry..... and the sound! Just awesome!

I personally have not experienced a Plazmaman fitted car so I can't comment on them.

Also, I strongly recommend to anyone to do a leak test of your intake plumbing. I thought my bro was being OCD pedantic but the results sure surprised me. I think there is another fella on here with a very similar setup who did the same thing and gained likewise results.

At the end of the day I guess it depends on whether your a numbers man and obsess over every lost/gained figure on a dyno printout or if you just want to drive the car and feel the differences.

Just my two cents...

End rant.

Edited January 21, 2015 by RBceffy25

[skylineking]

This is my experience with plenums etc....

My Old RB25 with standard Intake plenum, fmic, turbo back 3in ex, elec. boost control, PFC, standard turbo was good, nice and responsive with good low end pull.

My brothers RB25 with Greddy copy plenum, fmic, turbo back 3in ex, elec. boost control, PFC, standard turbo/then NEO turbo was fantastic, even more boost responsive and felt like it had even more pull.

So, front facing plenum with all it associated factors - less pipework etc. - was a noticeable improvement on boost response, which I feel negated any potential loss in torque.

It then went to GTR plenum and itb's, fmic, turbo back 3in ex, elec. boost control, PFC, HKS GTRS and poncams and four degrees of ex cam retard on PULP which was amazing. The snappy response from both turbo and throttle was amazing. The seat of the pants feel was fantastic. As soon as you touched the throttle it was so angry and torquey with a tiny bit of lag over the previous setups, obviously due to the larger turbo.

Then, identical setup but with E85. Same response with more overall power, of course.

With this setup it made 110rwhp and 7psi at 3k then 175rwhp and 12.5 at 3.5k

Then, in the quest for ever more response, we setup a home made smoke machine test to find any and all boost leaks, which the were several tiny ones all over the place.

The previous setup was retained - GTR plenum and itb's, fmic, turbo back 3in ex, elec. boost control, PFC, HKS GTRS and poncams, ex cam back to zero and no boost leaks. The result is incredible. It made a couple HP less peak - I think due to the cam timing change - but gained response, power and torque pretty much everywhere else. It now makes 140rwhp and 10psi at 3k then 240rwhp and 19psi at 3.5k which in real word terms feel absolutely incredible on the road.

In my experience, I honestly think the gains outweigh and overshadow any loss as far as plenums go. But, as WARLORD said, its definitely down to the entire setup. The sum of all the parts and attention to fine details make the whole. So, I think front facing plenums are a good thing provided the rest of the setup is in good order and refined.

I cant say enough good about the GTR ITB setup. I dont think it lost anything anywhere (torque,power) but then we never compared that exact setup with standard runners/plenum etc. The itb's really made the car feel soooo so responsive and just angry..... and the sound! Just awesome!

I personally have not experienced a Plazmaman fitted car so I can't comment on them.

Also, I strongly recommend to anyone to do a leak test of your intake plumbing. I thought my bro was being OCD pedantic but the results sure surprised me. I think there is another fella on here with a very similar setup who did the same thing and gained likewise results.

At the end of the day I guess it depends on whether your a numbers man and obsess over every lost/gained figure on a dyno printout or if you just want to drive the car and feel the differences.

Just my two cents...

End rant.

Cheers man that's some awesome input, enjoyed reading it very much. I'll be posting my old dyno run vs my new one once my car is back up & running hopefully to show a reasonable comparison between the greddy & plazmaman plenum!

However in the mean time I'm really interested in hearing about the way you guys went about testing for leaks. I'd love to do the same & see if my setup has any once it's back together! If it's something easy to do at home & save some $$$ that's always a bonus!

[GTSBoy]

However in the mean time I'm really interested in hearing about the way you guys went about testing for leaks.

Has been posted about heaps. Search.

[WARLORD]

Smoke test

[Ben C34]

Pressure test.

[Trex]

Smoke test.

[WARLORD]

Spot on stagea97 thats what im talking about

[skylineking]

Cheers guys ???? ?