RB20DET Tuning options

[superclarkey]

First off please don't say get a 2.5 or a 2.6 as I’m tuning the RB20DET ok

I've striped the engine down and I’ve bought HKS exhaust manifold (t3 with external waste gate) also a GT3071R with GT series 3 inch turbine out let and 4 inch compressor inlet on .64a/r.

Also have AP Engineering power fc and 550cc Nismo injectors.

I've bought an RB26DETT bottom end and striped the crank, rod + pistons out of it and plan to put it in the RB. Do you think it is wise to upgrade to after market pistons and rods and just use the crank??

Could you outline whats involved, anyone that’s done with pictures and finial results would be cool.

The head is another story, but it’s going to have all the tools for the job.

I'm aiming for super fast power for my RS13.5 200sx drift car (yes I know you'll say maybe a GT2871R or GT28RS would have been better, oh well)

I would like to use this thread as progress on the work I’m having done and at a later date I will do a full right up on the conversion as when I do it ect.

Any help or links would be very useful as info for the RB20DET is somewhat hard to come by in the UK.

Thanx for you time.

superclarkey

[Wazz]

depends on the power you want to go for if your goin to be running.. either way you'll need to do aftermarket pistons.. btw... how much roughly was the rb26 bottom end good luck with the build anyway dude

Warrick.

also... at least some people have respect for the lil rb20's now i know im not alone!!!!!

[superclarkey]

I love the RB20DET so revy and try as you will I’ve never heard of anyone blowing one up.... anyways back to the thread. lol

Umm I’m not so bothered about final "paper power figures" what the engine to feel smooth and responsive, I think the GT3071R is a bit big for my needs, but I can get other turbo at a later day if it is.

As say response is what I need, it’s a full spec drift car, and this is its heart so let’s sort it out.

For the bottom end I paid about £1k (but its in fully working order) and I’m sure I could sell the block on to someone willing to do some tuning.

Thanx for the reply.

[superclarkey]

Been talking to a guy today that is saying that the RB20DET with a GT3071R would be very laggy, what you think?>

[Wazz]

ever thought of a HKS GTRS? rated at 400ps.. apprently its got the response n mid range power of a GT25/30 but its also got the topend of a 25/40 so i've been told.. as soon as i get some cash together im goin to throw one on my lil rb20

[Roy]

Another believer:thumbsup:

RB26 rods will be fine, id say use 81mm aftermarket pistons, (Jap pistons range from 81-83mm) Even without using the RB26 crank you can get 2.2L out of a bore and pistons.

So some nice pistons, cleaned up RB26 rods will be majic in an RB20 bottom end. Thing is head, i have no idea about cams etc, but if its going to be a built motor...perhaps someone can offer real advice on whether you can use hydraulic lifters at the sort of revs you will be able to use courtesy of the bottom end.

Hell it should rev better then the RB26 as it has the same crank and rods, but lighter pistons courtesy of their smaller diameter:)

I have long thought about doing a similar thing with an RB20, but wimp out when im happy with the power my std motor makes:) That said go for a 8.8:1 - 9.0:1 compression ratio, tune the thing to 1.2-1.3 bar of boost with a good flowing head with cams etc, and you could very well end up with an animal of an RB that is responsive, powerful and sounds great / revs well:)

Im waiting to hear footage of my car at Phillip Island don the straight, a few people have said the RB20 sounded great:) LOL thing was i was typically only reving it to 6,500rpm and ppl still commented it was a banshee.

I dont think it wil lbe too laggy with the extra cc and compression and head work. When you condsider you will be able to pull 8,000rpm reliably, perhaps 8,500rpm if you go solids in the head, then so what if falls off the boil a little down low....my thinking is sports cars are meant to rev, the sound is intoxicating by itself. Shame with std cams i make do with a 7,000rpm rev limit:(

[superclarkey]

ever thought of a HKS GTRS? rated at 400ps.. apprently its got the response n mid range power of a GT25/30 but its also got the topend of a 25/40 so i've been told.. as soon as i get some cash together im goin to throw one on my lil rb20

Yeah, i was looking at a HKS GT-RS but i need it to be a T3 flange and external wastegate

[superclarkey]

Another believer:thumbsup:

RB26 rods will be fine, id say use 81mm aftermarket pistons, (Jap pistons range from 81-83mm) Even without using the RB26 crank you can get 2.2L out of a bore and pistons.

So some nice pistons, cleaned up RB26 rods will be majic in an RB20 bottom end.  Thing is head, i have no idea about cams etc, but if its going to be a built motor...perhaps someone can offer real advice on whether you can use hydraulic lifters at the sort of revs you will be able to use courtesy of the bottom end.

Hell it should rev better then the RB26 as it has the same crank and rods, but lighter pistons courtesy of their smaller diameter:)

I have long thought about doing a similar thing with an RB20, but wimp out when im happy with the power my std motor makes:)    That said go for a 8.8:1 - 9.0:1 compression ratio, tune the thing to 1.2-1.3 bar of boost with a good flowing head with cams etc, and you could very well end up with an animal of an RB that is responsive, powerful and sounds great / revs well:)

Im waiting to hear footage of my car at Phillip Island don the straight, a few people have said the RB20 sounded great:) LOL thing was i was typically only reving it to 6,500rpm and ppl still commented it was a banshee.  

I dont think it wil lbe too laggy with the extra cc and compression and head work. When you condsider you will be able to pull 8,000rpm reliably, perhaps 8,500rpm if you go solids in the head, then so what if falls off the boil a little down low....my thinking is sports cars are meant to rev, the sound is intoxicating by itself. Shame with std cams i make do with a 7,000rpm rev limit:(

Yeah, sounds a plan, i'm glad people think its a good idea, anyone know what works involved to get the crank rods and aftermarket pistons to fit ect??

I may get a turbo made to suit engine yet thou, but i'm getting very friendly with tomie and jun at the mement so lets see how it goes

THe head is going to be matched to the bottom end with new bore so its going to be a powerful motor:D

As i say will keep this thread upto date and what i learn along the way:D

Because the RB20DET is always swaped for the 2.5, i think it stands to be a monstor.

[Angry]

Sounds good to me clarkey.... im in the process of gathering bits and piece to build what Roy was talkin about. so far i have my crank, rods, cams, injectors, long motor, fuel rail and hopefully before too long ..81mm pistons..... from a Toyota 4AGZE ..i have a standard part number for em if your interested. (just gotta find where i put it)

i believe these are forged and ceramic coated from factory.... pretty neat i reckon. .... they'll go into a Rb20 with offset gudgeon bushes machined to suit the 4AGZE gudgeon pin ..i think to bring it down a little.. yet to fully confirm it. all of this info i'm passing on i got from SydneyKid.

They are a far far cheaper option than getting Tomei Pistons ..even if u can get them at cost price. over here $340(approx) for a set of 4 toyota pistons x4 is pretty damn cheap over the counter.

Any good machine shop should be able to machine your block to suit the RB26 crank diameter. im in no hurry with mine at the moment.. but id love to see more ppl actually do it rather than go a RB25 or other.

sorry for the lack of puncuation , im lazy

Matt

[superclarkey]

Angry, that is most interesting, 4agze pistons hey nice one

Thanx guys you really know your sruff about the old RB20DET

Anyone with info please step forward and share

[superclarkey]

Also my crank + rods are out of a R32 gtr, now is there any difference between the crank in a r32 to the rest of the GTR range?

[superclarkey]

Ok started attacking the engine today,

one thing i noticed onthe inlet cam caps a few of them were realy stiff? is this normal??

ANYWAYS HEAD IS NOW GOING FOR PORT + POLISH and a few other things

Click on picture to enlarge if you want a more detailed view

First the exhaust and turbo came off

Followed by the Plenum

Then the head just droped off

Gave it a bit of a clean and removed the cam gear and lifters (that are hydrolic and NOT solid)

And of course i made a detailed drawing of how all the parts go back to gether

Today was fun Me holding the exhust cam

[superclarkey]

BTW do you guys think it looks clean?? its only done 32k miles

[Sydneykid]

My first suggestion would be to do a search on "RB24", there have been quite a few threads on this subject. Angry and Roy have passed on most of what I have learned. I would certainly look at changing over to solid followers, even if you simply lock up the standard ones. Valve springs are usually a necessity, at the very least shim them up for more seat pressure. Once you have done those 2 things you can use any RB26 camshaft. I would be looking at 264's at least, and 272's if you can find them at a reasonable price.

I have seen a video of an RB24DET in an R32GTST doing a 9 at a HKS drag meeting on street legal tyres. So there is plenty of fun to be had.

Hope that is of some help:cheers:

PS; We use 8,250 rpm all the time in our RB20.

[makaveli]

Im quite sure you can get the hks gt-rs turbo with a t3 flange.

There is a couple of guys on the forums with them.

Some making around 250kw's on their rb25's with simple mods.

Good Stuff mate, the old rb 20 is great.

Unfortunately im to lazy to fix mine up so I just dropped an rb25 in.

Take it Easy

Mark

[Roy]

...PS; We use 8,250 rpm all the time in our RB20.

LOL...id love to pull those sorts of revs...but i am so over not driving the car, and dont want to brake anything at all in 2005, although after PI my box is feeling very ordinary:(

A few other things, which id love to put on my std RB20 to make sure that it lives when being enjoyed:)

Is it worthwhile bolting on an RB26 N1 oil and water pump. Especially if your going to be getting up around the 8,500 range, id want to be sure the ancillaries are up to the job.

A few other things that have been in the back of my mind for a while and not been able to get answered. The Greddy alloy pulleys for an RB26, do they fit other RBs?

I have to ask, if you got an RB26 bottom end at a good price, did you ever consider just grabbing an RB26 head?

Be great to see this done, good luck with it

[superclarkey]

would you belive i've just sorted out and R32 V-spec crank and rods even cheaper (spares)

I want to stick with the RB20DET head as its going to be cheaper to tune

Here i come RB24DET

[Angry]

u'll only achieve 2.4litres if u go 82mm tomei pistons. with gtr crank and rods.

with 81mm pistons u'll be around the 2.3litre mark ...basically the same difference end of the day.... but ..i would think the 2.3 would be slightly more rev happy. but it would be a poofteenth of a difference between the 2.3 and 2.4....

Matt

keep us posted clarkey

[superclarkey]

I think i'm going to go Tomei 82mm pistons anyways, because i'm going to get my cams and pulleys, springs and valves too.

[browny]

superclarkey

Would you be able to do me a favour whilst you have the RB20 in bits....

Can you measure the RB20 conrod length for me?