Rb20De+T - 300Kw+ Range

[nisskid]

Hey guys, chucking together another engine, trying out with a NA RB20 on jungle juice e85, was running a TD06 20g on the last 20(DET), made around 300rwkw, super happy with the response, lag was never an issue, have another car i use for small tracks which has response, this engine will be more for open tracks, wanna see what i can stretch the little 20 to, more of an experiment more than anything. Have a HKS twin scroll mani i'm using, and still have the TD06 although it may be in need of some love (it's had a good innings), also have a precision 6265. precision is a bit of a jump, but considering it's there and wont cost me anything, i'd be willing to try it, i've definitely had laggier setups, then change if it proves too much of an issue.

The td06 25g is an obvious option, but i'd like to see if i could utilise the twin scroll manifold, ideally a ball bearing turbo, and with the high compression, squeeze around 330rwkw with around the same lag as the td06 20g, at less boost (26psi, had control issues). the limiter is going up to 8000rpm and possibly up to 4.6's from 4.1's. any ideas on a good turbo in that range, BB twin scroll, or is it not worth it?

while i'm at it, looking into a forwards facing plenum setup, possibly adapting the RB26 itb setup, but unsure if it will help with midrange, or hinder. For me, the benefits of simplicity and clearance with them are extremely beneficial out on the track, so i'd like to justify one performance wise as well. any thoughts on that one too?

cheers

[ARTZ]

T67 will bolt up.to your tdo6 housing and provide the extra power

[nisskid]

T67 will bolt up.to your tdo6 housing and provide the extra power

thanks mate, was looking at those, but obviously that will still be keeping the journal bearings and no twin scroll.

[battery]

Did Roy end up running the T67 on his?

maybe look at the HTA 3076r

[zebra]

6265 is way too big...they are a bit laggy on 2.5s but will make 400+

T67-25g would be my pick if you aren't fussed on having to rev it to the moon and back

Sooooooo....buy some good valve springs and rev that mofo!!!

[nisskid]

i ran the precision on a 25 with a cheap chinese intake manifold and cheap NZ s/p ex mani (junk, but bought car as is), and it was pretty laggy but worked, only issue was when i went up to competition tyres, the clutch was too doey to keep the rpm up for it's setup. but it is a v-band housing-manifold, and it was running a cheap v-band so was leaking like a sieve. the 32 runs a much bitier clutch, hopefully decent plenum, the hks mani with no leaks, higher rpm (and higher ratio to suit), so i'd imagine it would be on par if not maybe a bit better even without the extra 500cc capacity. after currently running the same td06 turbo on both RB25 and RB20, i can say with all confidence that i much prefer the RB20's setup, however it did run e85 and more boost, but it was much stronger through the power region which counted for me (top end). The RB25 i run now with TD06 20g is better on the low speed stuff, but the 20 was still managable on the low speed, but had way more to give on the higher speed stuff.

[White GTS-T]

BorgWarner's new EFR 7163 would meet your goals. A bit exxy though

[Dan_J]

rb20de+T will work well for response... drop in det cam shafts as they are different... adjst cam gear advance intake and retard zorst will net you more response.

intake mani- the ones that bolts on top of the factory one are bent to be better due to longer runners, although the ones like greedy one piece will hinder power/response due to shorter runners

hypergear aint doing too bad, check out the ss range

[nisskid]

only going to 8000rpm so standard springs should be sweet, i assume they are the same de and det even though there are slight lift differentials?

as far as intake, i'd love the ITB's, really like throttle response, if it's too much work i won't bother, but it'd be ideal if i could utilise it. Just not sure how, looked into cutting and shutting, but where? possibly cutting off the runners right at the flange, running some tubing with a laser cut flange to suit rb20? could be a chance to add some length to runners if they are a little short standard. not sure how that will play with fuel delivery but will be run with motec m500 which should allow some control.

[Dan_J]

only going to 8000rpm so standard springs should be sweet, i assume they are the same de and det even though there are slight lift differentials?

as far as intake, i'd love the ITB's, really like throttle response, if it's too much work i won't bother, but it'd be ideal if i could utilise it. Just not sure how, looked into cutting and shutting, but where? possibly cutting off the runners right at the flange, running some tubing with a laser cut flange to suit rb20? could be a chance to add some length to runners if they are a little short standard. not sure how that will play with fuel delivery but will be run with motec m500 which should allow some control.

think its slight lift and duration difference which might cause power band issues, seeing that your after as much power as you can get out of it . should just rack them out of the broken det

[nisskid]

yeh sorry i meant the valve springs, i'll poach the cams from my current det.

[iruvyouskyrine]

Not any real input, just a question. Wouldn't running ~26psi on a DE+T kill it very very quickly? I know running ethanol will help but surely running high comp and high boost would lead to extremely high cylinder pressures that the NA rods just can't cope with? Don't really know too much about all this stuff, hence the question. Genuinely curious.

[nisskid]

going to give it a whirl, plenty examples around with 30de and 25de's, i'm not planning on running 26psi, that was my old setup on the DET, it actually ran aroud 30psi most of the time due to control issues. never bothered to fix it as it never had any problem running it all day every day haha.

plan is to run 17-20psi (maybe higher if the turbo i use needs it), the E85 is pretty amazing stuff. afaik RB20DE rods are the same as RB20DET rods? or at least strength wise. haven't pulled one apart yet to confirm, if they are weaker that'd be very usefull info. main worry atm is lack of oil squirters, but looking at RB30's i'm thinking it's not the end of the world.

[Simon-S14]

na rods and DET rods are the same, in fact the whole bottom end construction is the same, just the CR changes. also boost pressure doesnt kill engines (to a point) rather its excess or uncontrolled cyln pressures that does. if you can get the tune right and control the combustion you'll have a happy engine that runs right!

thankfully Nisskid and myself have a tuner who is more then switched on enough to do the job. case in point is my own car that just keeps going and making 400+ rwkw on stock rb30e bottom end

[Simon-S14]

and yes stewy... RB30E has no squirters.. reckon its of any concern to my motors in the battle car or my s14? not really lol

[iruvyouskyrine]

na rods and DET rods are the same, in fact the whole bottom end construction is the same, just the CR changes. also boost pressure doesnt kill engines (to a point) rather its excess or uncontrolled cyln pressures that does. if you can get the tune right and control the combustion you'll have a happy engine that runs right!

thankfully Nisskid and myself have a tuner who is more then switched on enough to do the job. case in point is my own car that just keeps going and making 400+ rwkw on stock rb30e bottom end

Wouldn't running more boost increase cylinder pressure? Or is the difference between 10 (standard) and 26 psi hardly worth noting when cylinder pressure is so high anyway?

[GTSBoy]

9:1 compression ratio means that whatever you put in there to start with gets squeezed up to 9 times the original pressure. If you start with no boost at all, then you end up with about 9 times atmospheric pressure. If you run 10 psi boost on top of atmospheric, then you have (14.7 + 10)/14.7 to start with and then you squeeze that 9 times. So now instead of maybe 132 psi, you have maybe 222 psi. And if you were to start with 26 psi of boost, the ratio now gives you 366 psi.

So, yeah, 26 psi does make a hell of a difference to cylinder pressures compared to 10 psi. That's the whole point.

** Note that I've only done simple ratios up there and haven't taken into consideration any aspects of head flow efficiency or non-adiabatic compression effects etc etc. It's just for illustration.

[StevenCJR31]

Unless ive missread wiki. . The DE and DET cams have the same lift and SLIGHTLY different duration. . .so little difference that they wouldnt be worth the time swapping over

[Dan_J]

takes less then 10 mins to swap over and yeah about 3-8 degrees of duration difference although i wouldn't trust wiki for solid specs

[nisskid]

http://www.tomei-p.co.jp/_2003web-catalogue/e090_camshaft-specs.html

this is what im going off.

still struggling with turbo choice, thinking about grabbing a new rear housing, maybe a touch smaller and twin scroll (assuming that's possible, feel a bit rookie asking, but i assume twin and single scroll internals are the same besides the housing, blade design isn't different?) for the precision, here are my choices
https://www.treadstoneperformance.com/product.phtml?p=2169&cat_key=596&prodname=Precision+T4+V-band+Turbine+Housings%2C+Twin+Scroll

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1.00
1.15
1.32