A Boy's Love For His Rb20

[Russman]

Its only natural that the setup find s it's way onto another black R32

Agreed. It will go on to conquer all.

[Roy]

Ok, so the quest continues.

Bought a new turbo this week. So the plan is the 10cm housing goes on next week. Thinking is that the plenum seems to have lost a little in the middle but seems to be a bit happier up top. But just wont make any more power so guessing its the lil 8cm housing. Will see what the 10cm housing does...

So along with that I am taking off the ARC 100mm thick cooler and installing an R34 GTR cooler. Hopefully being a bit smaller in volume we may get a bit of punch. I am a sceptic so will be interesting to see the result of that back to back. When the RB24 goes back in I may throw the ARC cooler back in, but perhaps 100mm cooler is simply too much core for a lil 2L.

So, after the cooler nad 10cm housing and tune it will be decision time. If the 8cm housing looks to have bene the culprit for holding back the bolt ons the cams will go in....but meanwhile. The kinder surprise bitsa motor will have the following turbo setups to trial:

- TD06-20G with 8cm and 10cm housing

- T67-25G with 8cm and 10cm housing

- TD06-25G with 10cm housing

and if i can get a minute with working this weekend will try to fit the Stoptechs this weekend

[sav man]

Just put a Garrett on

[Roy]

Truck turbos rule yo!

[SABBAi]

I hear ya brother!

Bush bearing all the way...

[bigmikespec]

I love the look of the Trust/Greddy comp. covers! Hope it works out well.

[Roy]

So, as you can see it kills response but does help flow at the very top end. But the combination of the plenum and other recent changes now means I have lost about 30rwkws through the mid range :( :(

Will see how we go with a few more trials and erros, may as well throw the 10cm housing on it now and see if we can break 295rwkws...fark knows it needs way more top end now it has lost the response that made it pretty damn quick for a 2L

As you can see at 116km/h i used to have 20psi and 185rwkws. Long live std cams, plenum and a full Greddy setup rather then 6boost and Turbosmart mani-gate setup

[DJRIFT]

a question. why do you use road speed rather than rpm? i have never had anything done with road speed so i dont understand it.

[sav man]

usually means the tuner is too lazy to put the drive ratios into the dyno.

[Roy]

But even then tyres are all different sizes so cheat the truth a little. Road speed is road speed is road speed. At the end of the day you go through corners at a certain speed not rpm...so understanding what the car is doing at that road speed makes it easy to work back from (IMO)

Sav, real interested to see how you go with your plenum...before tuning your car I would be going back to the std plenum if i were you. No way an RB26 throttle body with its bigger bore etc is going to be a good thing on an RB20 (pure speculation but just a feeling i have) And since you are racing your bus...throw the 26 throttle bodies in the bin. Ideally grab something with a smaller diameter and use the phenolic gasket etc to try and get some runner length back

[sav man]

i've been quite surprised with the car. Damo's done more driving than me cause i've been tuning it, but i've found it nice and responsive when i have driven it. Throttle response is much better than std. All in all i'm pretty happy with how mine feels, esp since it's running flat 15deg timing and 10psi of boost.

[Beer Baron]

troy.

sell plazmadude plenum. refit old standard plenum with nice piping you had (i always liked it)

buy or refit trust mani and trust gate (we both know they are both good bits of gear)

enjoy.

I agree the 100mm ARC core is too big. go to 70mm ARC core. they are same size as stock GTR core, are LIGHTER than a stock GTR core, flow more, cool more and also allow more air through to the radiator due to better design. that's what you want.

then you will be on the path to greatness.

[Beer Baron]

oh, and agree with troy road speed is the way to go for the bottom axis on the dyno. also much easier to compare and does not allow people to 'lie' by doing runs in 3rd gear etc as it instantly shows up with the speed.

[DJRIFT]

oh see i was always of the impression that the dyno picked up engine RPM by one of the probes as you can pick up RPM from just clamping onto the battery for example.

so i would have thought that comparing engine parameters like spool time ect would be better done back to back with true engine rpm as like a KW reading there is several factors that play a part. just strapping a car down tighter can change a reading.

i can easily see where road speed can be used but if your trying to compare apples with apples shouldnt the most constant of all variables be used?

[DJRIFT]

Sav, real interested to see how you go with your plenum...before tuning your car I would be going back to the std plenum if i were you. No way an RB26 throttle body with its bigger bore etc is going to be a good thing on an RB20 (pure speculation but just a feeling i have) And since you are racing your bus...throw the 26 throttle bodies in the bin. Ideally grab something with a smaller diameter and use the phenolic gasket etc to try and get some runner length back

theory and reality dont always go hand in hand. we have a dyno proven 295rwkw stock internal rb20 with a rx6 turbo on a stock exhaust manifold running at the circuit. most people would say thats not possible. mainly the stock manifold bit.

the thing is at the end of the day were happy to trial somthing different just the same as you are but we havent had the luxuary to trial it back to back. we will more so just look for the small details and compare it to similar modded rb20s we're involved with. if it has such dier results im sure they will pop up. while we both love to jaw off about how cool it is, we arent going to market them to the world so we dont need a fancey dyno proven figure to tell people what they will do. i initaly did mine as a cost cutting exercise as a plazman was to expencive for what it was. a custom made welded thing would have cost similar due to paying a profesional to weld it all up and the setup i have ment i made 95% of it at home so the cost was only in the odd bits i needed.

[Roy]

Yeh, but arent you running an RB25? The aerodynamics of the RB26 plenum on an RB25 are going to be simimlar. The gas velocity and cylinder filling etc on an RB20 will be different. Not saying different is bad, different could be better then std.

Hear what you are saying about not needing dyno figure, but its handy to see the characteristics of performance changes. Driving the car didnt really feel tht different, but dyno suggests there is a fair bit...i wont know until i drive the thing in anger and in whch case any loss in response will be very noticable

[sav man]

is't the plazman plenum just a replacement for the top 1/2 of the rb20 inlet? IE it keeps the std runners.

The local guy here with the 295rwkw made his own plenum using the same idea as the plazman, and he can't praise it enough.

Spose the question is, do the dyno figures always match the real world? As you said you probably won't know till you go the the track and see if loss of response on the dyno equates to anything.

[Roy]

is't the plazman plenum just a replacement for the top 1/2 of the rb20 inlet? IE it keeps the std runners.

The local guy here with the 295rwkw made his own plenum using the same idea as the plazman, and he can't praise it enough.

Spose the question is, do the dyno figures always match the real world? As you said you probably won't know till you go the the track and see if loss of response on the dyno equates to anything.

Yeh, it bolts to the top half of the plenum. To drive it doesnt feel voerly different. Unfortunately I dont have the logger installed so couldnt really compare 2nd, 3rd and 4th gear acceleration plots to see where the truth lay...dyno , seat of pants or somewhere in between.

I have tried to control the before and after as much as possible, same boost controller, boost, tuner, dyno etc etc. So all I can talk to are my experiences but as a result i probably will question the results of others just to understand why I am in the position I am in.

Re dyno figures and real world results...i suppose often there are stories where dyno improvements are not translated to real world gains. I am not sure there are too many stories of dyno showing losses but you have improvements?!?!?! The throttle response is no better or worse really so ... time will tell...some more things to try over the coming weeks

[irishGTSr32]

Heyya doing man!!!

What a build to start off with.... also building a angry rb20 at the min along with a plazmaman,

tho surly it wouldnt bolt on and show improvement with out mapping

[Roy]

So the tune has been tweaked with the new inlet manifold on and the results are not that encouraging This weekend I will work on the cooler pipes some more, check a few more things and see if there is anything to be gained. Then will replace the big 100mm ARC cooler with the std R34 cooler I have got in the boot and then its just a matter of throwing my Momo seat that I got out of storage back in, bed the new brakes and hopefully be able to start enjoying it again.

Still got to put the new radiator, thermo fans, low temp thermostat and new hoses in too....but thats all stuff for a lazy weekend