UAS RB20/25 Intake Plenum.

[JaFF]

you'd think that whoever the owner of the car was would be better off spending the $1500 on a powerfc and tune if they're still running the stock computer.

anyway, dyno graphs? am i invisible?

[Sydneykid]

plenums like this do make alot of difference. me and my mate tested the difference between our cars, both stock rb25's, mine had custom plenum, same size turbo. mine would kick in at 2200 and hit 1 bar by 3500 and his would kick in at around 3500 and hit 1 bar by 4500 rpm. although his was running stock computer with a safc and i was running a microtech LT-16s, im sure that tuning didnt make that much of a difference.

You're kidding right. otherwise you wasted your money on the full ecu replecement. You could tune igntioin timing and he couldn't, and that the biggest single factor in improving response.

[carl h]

for less than 1500AUD i got a very well made intake mani by RIPS in NZ, as for power #'s ive no idea as my engine is still sitting on the stand awaiting cams to make use of the free flowing intake plenum and the hks exhaust mani i have now.

[Sydneykid]

Even if the custom plenum doesnt give gains in horsepower which is debatable there would still be sustantial gains in throttle response in the form of reduced throttle lag am I correct.

Nope, the throttle butterfly on a front fed plenum is further away from #6 and #5 than standard.

And wouldnt the shorter pipes improve inlet temps thus horsepower?

Again nope, it's simple mathematics the air travels though the pipework so fast is hasn't time (or sufficient contact area ) to pick up any temperature. The numbers look like this;

5,000 rpm X 2.5 litres / 2 (its a 4 stroke) X 2 (1 bar boost) = 208 litres per second.

[LANFOH]

Nope' date=' the throttle butterfly on a front fed plenum is further away from #6 and #5 than standard.

And wouldnt the shorter pipes improve inlet temps thus horsepower?/QUOTE]

Again nope, it's simple mathematics the air travels though the pipework so fast is hasn't time (or sufficient contact area ) to pick up any temperature. The numbers look like this;

5,000 rpm X 2.5 litres / 2 (its a 4 stroke) X 2 (1 bar boost) = 208 litres per second.

So basically what your trying to say is using the standard throttle body and plenum is just as good as if not more efficient than a front fed plenum?

[Sydneykid]

you'd think that whoever the owner of the car was would be better off spending the $1500 on a powerfc and tune if they're still running the stock computer.

And if it already had a Power FC, I would vote for a split dump and hi flow cat. Then a decent clutch to hold the power, then a set of injectors, closely followed by a fuel pump to supply them. Then a pair of Tomei Poncams, a turbo, exhaust manifold etc etc

It has been my experience that all of these would give a more substantial power gain than changing a plenum.

Don't get me wrong, a plenum upgrade would be on my list and the UAS one looks very nice, but it sure as hell would be a long way down my list:cheers:

[Ben101]

Boosted zed with the manifolds are you polishing the inside of the chamber and trumpets? As ive been taught that you need a rough surface to help atomization of fuel and air mixture! If there polished to much it wont work to its full capabiltiles!!

[Abo Bob]

Perhaps John did this to a car with a stock computer and exhaust to show what his plenum can do. It looks more like an exercise for demonstration rather than a "hey do this mod first" thing.

I'm sure he is going to post a before and after Dynograph for us to ogle. If he hasn't got them already it would be worth his while to do so if it proves him right.

[KamikazeR33]

SK: i would have imagined a 500rpm difference with an ecu, not 1000rpm

[Sydneykid]

Perhaps John did this to a car with a stock computer and exhaust to show what his plenum can do.  It looks more like an exercise for demonstration rather than a "hey do this mod first" thing.

 

I'm sure he is going to post a before and after Dynograph for us to ogle.  If he hasn't got them already it would be worth his while to do so if it proves him right.

John has aready posted the "after" dyno graph.

It was done on Wednesday 3rd November last year.

Ambient temperatuer was 22 degrees so it was a cool day for November

Boost was 12.6 psi max, dropping to 10.5 psi at 6,900 rpm.

John mentioned that it had a "standard dump and engine pipe", to me that means it had a hi flow cat and a cat back exhaust. Must have been a good one to be producing increasing power over 6,200 rpm.

John's post is a little confusing to me, but since he mentions "end tanks" and "USA core", I assume the car had the UAS intercooler and pipework as well.

So the only thing that stands out to me is the "standard ECU", I would never be able to get a "standard ECU" R33GTST to 208 rwkw. The ECU would go rich and retard (based on the AFM voltage) long before I could get to 185 rwkw, let alone 208 rwkw.

[CerealKiller]

you'd think that whoever the owner of the car was would be better off spending the $1500 on a powerfc and tune if they're still running the stock computer.

anyway, dyno graphs? am i invisible?

* UAS RB25 Plenum & Intercooler

* 12 Psi

* Standard ECU

* Standard Turbocharger

* Cat Back Exhaust

* Pod Filter

I doubt a PowerFC and tune can yield as much gain with just a cat back and pod...

[JaFF]

are you syaing that a power fc would yield less than a plenum? which is the point of discussion here

[browny]

* Why design the unit as a bolt on top half (rather than welded to the lower half of the runners ala RIPS style)?

I've got two issues with the two piece design. First, maintaining a nice flat surface to get good gasket sealing is more of a problem (ok, machining will solve this, but you don't need to worry about this with a one piece design). Second, you introduce potential for air leaks around the bolts holding the two halves together (which can be avoided using blind holes or lots of thread sealant - but once again not a concern with the one piece design).

* Is the end offset to accomodate the clutch cylinder on Rb20's?

* Does the plenum accept all std sensors and actuators?

[BBQ]

The only way that car could possibly produce those kind of figures are,

#1 if it was running C16 which would give high hp increase.

#2 the dyno is reading wrong. - "Air intake temp sensor"

#3 The base timming has been advanced well past 15* BTDC

And, Stock Dump Pipes would be creating that much back pressure, The turbo would be chocking on its self.

[KamikazeR33]

guys let the argument go.

John has posted to let everyone here know of his new product and the results they got. if u doubt it y dont u go see him urself or pm him. im sure when he gets time he will post up all the details of the car.

[Abo Bob]

So the only thing that stands out to me is the "standard ECU", I would never be able to get a "standard ECU" R33GTST to 208 rwkw. The ECU would go rich and retard (based on the AFM voltage) long before I could get to 185 rwkw, let alone 208 rwkw.

http://www.skylinesaustralia.com/forums/at...achmentid=25735

This car has:

209.5kW 96 Series 2

Engine management - Stock ECU

Boost ran - 12psi

Turbo - HKS 2540

Fuel used - BP Ultimate

Stock all other internals.

Blitz DSBC 1st gen

Hybrid Front Mount

3" Exhuast from turbo back

Pod Filter

Stock BOV

[BBQ]

http://www.skylinesaustralia.com/forums/at...achmentid=25735

  This car has:

  209.5kW 96 Series 2

  Engine management - Stock ECU

  Boost ran - 12psi

  Turbo - HKS 2540

  Fuel used - BP Ultimate

  Stock all other internals.

  Blitz DSBC 1st gen

  Hybrid Front Mount

  3" Exhuast from turbo back

  Pod Filter

  Stock BOV

Yes all nice, with a HKS turbo. But the car of intrest is:

SKYLINE R33 GTS-T

UAS RB25 Plenum & Intercooler

12 Psi

Standard ECU

Standard Turbocharger

Cat Back Exhaust - Stock Dump Pipes

Pod Filter

208.4 KW AT THE REAR WHEELS

From UAS web page.

[Abo Bob]

Sigh.

[Wazz]

that 2540 is a bit of a laggy hoe

[B-Man]

He he - I knew this would happen.

John - get my old car. Do a dyno run before (with the Greddy plenum). Then take the Greddy plenum off - Put the UAS one on , with the polishes bottom runners and then put it on the dyno again - then post the dyno graphs of before and after.

I am not saying one is better or worse then the other - just a comparison.

I don't the answer - but I do know that from looking at a front facing plenum and the flow direction, it seems to ME that they make better sense than the standard ones. The standard ones to me shoot air directly into ports 3 & 4 - But as SK says he doesn't see this with his analysis.

Keep up the good work.

Cheers,