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Rb26 Greddy Plenum Vs Stock Plenum

im late

By im late,
in Engines & Forced Induction

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im late Proficient

im late

Posted
Posted

Hey All,

I am going to paint my plenum black but it will mean my car will be off the road again (which is no good for me).

I thought I might buy a GReddy Plenum, get that painted and then swap it over in one day (I have to replace my knock sensors as well once the plenum is removed).

The question is, is it a worthwhile upgrade? My mod list is quite high:

Built/Forged 26

Arias Pistons

Argo Conrods

R33 GTR Crank

Balanced Bottom End

1.6mm Head Gasket

Jun 272 10.5mm Lift Cams

Tomei Cam Gears

Jun Oil Pump

N1 Water Pump

Trust Sump Extension

ATI Balancer

GReddy Pulley Kit

6 Boost Manifolds

GT2860-5's

Trust Dump/Front Extensions

Apexi PFC D-Jetro

Sard FPR, Rail, 800cc Injectors

Splitfire Coilpacks

Bosch 044

So maybe it will give me that extra flow.

Anyone here bought them and was happy/disappointed?

If it is not a worthwhile upgrade then I will just buy another stock plenum and paint that.

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https://www.sau.com.au/forums/topic/265591-rb26-greddy-plenum-vs-stock-plenum/
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Grunter Community Regular

Grunter

Posted
Posted

Mate if I was you I would save your money and paint the std one.They get big power levels with the std plenum still in place.

You can spend the money to improve something else on the car.Why not just send the old plenum down to the painters early

in the morning.While your waiting for that to get painted you can change the knock sensors and what ever else you need to

do to the car in the meantime.I cant see why you cant get it done all in 1 day just have to be carefull not to chip the new

paint still maybe a bit soft but the painters should stick it in the oven for you though.

a31lunacy Proficient

a31lunacy

Posted
Posted

depends on what power your aiming for i think the stock plenums do alright /on par up until around the very high end lets say 500 kw then when your trying to squeeze your motor for everything go for a greddy one

femno Grand Master

femno

Posted
Posted

Yeah...I dont know about that. I wouldnt.

The collectors can warp over time, I know mine was bent like a banana when I checked it, I wouldnt risk the 2 odd hours each way for a day or so of your car being off the road...

Better to keep the entire intake side in sets.

shanef Grand Master

shanef

Posted
Posted

some of the fastest timeattack/circuit cars run single tb's. 1 explanation i've been given from the owners is that the std plenum/tb's flow approx 30% less than say a hypertune plenum/90mm tb, throttle response is as good if not better.

not to mention the std plenum is known to run leaner at the back than the front

Cjmartz2k Proficient

Cjmartz2k

Posted
Posted

Lag or less throttle response? Switching from a stock 25 intake to a stock 26 intake with ITB's and lost noticable low end due grunt to the short runners on the 26 intake. I think my friends home made short runner intake for his 25 with a Q45 has pretty snappy throttle response, even compared to mine. I think throttle response is kind of one of one of those over rated internet buzz words. It sounds real snappy blipping the throttle out of gear, and I get almost feedback when I hit the gas in gear, but I'm not sure how much faster I am.

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Yes but its how the car "feels" as much as anything else.

A car that feels doughy and sloppy is not a good end user experience ;)

A car that feels nice and snappy, responsive is much more rewarding and fun.

Whilst over a 1/4 mile it might run the same time (under full load etc), but its driving around town where you appreciate a nice snappy feel like that.

femno Grand Master

femno

Posted
Posted

I cant see how you could possibly have better throttle repsonse with a single TB compared to six smaller ones basically bolted straight to the ports in the head?

As for lean on one cylinder, most a/m plenums have the same problem anyway with distribution.

Has anyone driven a SR20 Silvia then driven a GTI-R straight after? Tell me you cant notice the difference...not power wise but response.

And you cant really compare a built 26 with std TBs which probably runs lower CR too. My car is slightly 'doughy' compared to a factory 26.

Cjmartz2k Proficient

Cjmartz2k

Posted
Posted
Yes but its how the car "feels" as much as anything else.

A car that feels doughy and sloppy is not a good end user experience :D

A car that feels nice and snappy, responsive is much more rewarding and fun.

Whilst over a 1/4 mile it might run the same time (under full load etc), but its driving around town where you appreciate a nice snappy feel like that.

I can completely agree with that. :P I just wanted to throw out there that it is the particular effect everybody if chasing with these mods and all this effort, not more hp or better low end power. A lot of people out there confuse the two I think.

shanef Grand Master

shanef

Posted
Posted
^^ ye and they also are not street driven.

Race cars, dedicated track cars, always bad examples.

As for the lean, that's simply and easily fixed with some minor correction/trim when getting tuned.

not street driven but throttle response and low end power delivery is almost everything. same as why most cars run low mount twins instead of big singles.

so ud rather have a poorly designed manifold and tune out the flaw? I'd rather have a proper manifold that flows evenly as possibly.

Id still like to see back to back flow tests.

Stock response? Id like to see that honestly! So far the single tb cars ive driven have had a noticible lag time

how was the heads setup on the different cars? did the different cars have the same tune? or did some ahve shitty fueld up tunes and some nice and crisp?

I cant see how you could possibly have better throttle repsonse with a single TB compared to six smaller ones basically bolted straight to the ports in the head?

As for lean on one cylinder, most a/m plenums have the same problem anyway with distribution.

Has anyone driven a SR20 Silvia then driven a GTI-R straight after? Tell me you cant notice the difference...not power wise but response.

And you cant really compare a built 26 with std TBs which probably runs lower CR too. My car is slightly 'doughy' compared to a factory 26.

only the crap plenums that only look pretty have the shitty in-balance of flow, the proper ones are near perfect 1-6.

Who?

no1, i was having a dig :blink:

N1GTR Grand Master

N1GTR

Posted
Posted
how was the heads setup on the different cars? did the different cars have the same tune? or did some ahve shitty fueld up tunes and some nice and crisp?

Stock heads both cars

Both tunes were freshish, cars both well taken care of with quality parts used

shanef Grand Master

shanef

Posted
Posted
Stock heads both cars

Both tunes were freshish, cars both well taken care of with quality parts used

i bet both were 2.6's though, silly kents shoulda went 3.0, problem solvered

bit ot but i hate how 26's are down low, throttle responce mite be 'snappy' but theyve got n o t h i n g until about 4

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