Head Setup For Td06 Rb20 - Cams/gears Etc

[nisskid]

hey guys, a lot of reading down, but not a lot of definitive answers. will be going a td06 20g setup soon on my rb20, and wondering if i should bother touching the head or not. Being a drift car it spends almost all it's time above 4000rpm, with a limiter around 7500, possibly a bit higher. Drive-ability below 3.5-4k rpm is almost irrelevant, a strong power band from around 4-4.5krpm to 7.5krpm is what i'm after. I'm happy to go aggressive cams if need be, but if there are only very small gains in going a lift which requires new springs, then i can't be arsed going that path. i have some poncams sitting in an rb25 i have laying around, which i was thinking of nicking for the 20, but i know they are still considered mildish, wondering if it's worth going something more aggressive or not.

Also wouldn't mind people's thoughts on adjustable gears, although i think i've read enough on that topic from your average joe blow, would like to hear from someone who deals with them on a day to day basis tuning with them.

cheers guys!

[sav man]

I havn't seen any proof that cams do anything for a 20. From what I have tested and observed the inlet manifold is more of a restriction. A 20 down here has had a big prot job, and poncams and falls over at 7300rpm (GT3071r). My 20 with short runners, std everything else, and a RB20 highflow holds it power to 8000rpm. 20's already have big cams for the size of the engine. You wouldn't want anything bigger than a poncam, as I know they flow enough for 10,000prm and 550rwkw on a 25.

The exhaust side on the 20 head can do with some loving, I took heaps out of the exhaust ports. On the onlet side I only cleaned up the casting marks. I changed too many things at a time to know if it made a difference though.

[GTScotT]

Roy has shown the stock cams are good, lots of sporadic posts about how performance was lost in some cases.

Stock cams and a bit of a dial to suit your application. TD06 20G 8cm and its a good little package.

[nisskid]

I havn't seen any proof that cams do anything for a 20. From what I have tested and observed the inlet manifold is more of a restriction. A 20 down here has had a big prot job, and poncams and falls over at 7300rpm (GT3071r). My 20 with short runners, std everything else, and a RB20 highflow holds it power to 8000rpm. 20's already have big cams for the size of the engine. You wouldn't want anything bigger than a poncam, as I know they flow enough for 10,000prm and 550rwkw on a 25.

The exhaust side on the 20 head can do with some loving, I took heaps out of the exhaust ports. On the onlet side I only cleaned up the casting marks. I changed too many things at a time to know if it made a difference though.

thanks mate, yeh seems there's such a disagreement with what will benefit the rb20. this is my current setup, a 25/35 with standard everything:

and here's kris's td06 setup with hks cams

both have a huge drop in torque near each other, around 6000rpm, would love to get rid of this and run the engine up to 7500 and make steady torque at least past 7000.

i honestly probably wouldn't bother with any porting on this engine, i'm not sure how much life it has left, so mainly looking at bolt on solutions. the next engine i'm going with is a whole different story, but this is an inbetween atm.

[nisskid]

Roy has shown the stock cams are good, lots of sporadic posts about how performance was lost in some cases.

Stock cams and a bit of a dial to suit your application. TD06 20G 8cm and its a good little package.

only thing was, he did plenum and cams at the same time didn't he? the question is how much was the plenum, how much was the cams. talking to decs from garage 7 he has a lot of faith in the standard manifold, makes me wonder if that whole drop was to do with the aftermarket plenum.

[STATUS]

I have a gt2535 on my 20 and it hits a huge wall at the same rpm as yours and Kriss (and all rb20's). i have also had another with a gt3076 and step 2 cams fall off at the same point... working on a few things to test once we get the upgraded hardware for the dyno in a fortnight.

Cams are not the easy answer unfortunately. Tried every combo of cam timing on both setups too with no love..

Its also interesting to note the drop off is less obvious on roller dynos as wheel and roller inertia flatten it out a bit. One of my customers did not believe that the drop off wasnt tune related so i asked him take it elsewhere to get it checked... he did on a mainline it looked kinda normal but once i ran it back on mine it was the same as before..

the drop off seems to be at the same point but at different power levels... the 3076 made killer power but the drop off is more pronounced.

[Roy]

I cant make any sense from my results vs others either Hell I run E85 and don't make any more power so on my car there is obviously something stopping me from making more then 275rwkws.

I love how the 20G makes more power at 4,000rpm then the 2535, and way more torque when you consider that whilst they seem pretty even the diff ratio is lower in the 20G setup.

I did the 260/8.8 cams years ago and they sucked. About Feb last year I did the inlet plenum and whilst it really stops the diving over at 7,000rpm it does make the mid through 4,000-5,000rpm a little doughier. It is possible that what I am about to try tomorrow may liven up the Plazmaman install as there is something in my setup that is a point of debate and will test the theory tomorrow. So trying not to get my hopes up but thinking there may be life in the Plazmaman setup yet...which may also see a better result with E85

My 2c is if the head is off then give it a tidy up of casting and match port the thing. Give the head a shave and try to get a budget RB25esque 9.0:1 compression ratio out of the thing. If the engine is all together then don't touch a thing. Run the std inlet with a Greddy or OBX exhaust manifold and std cams. You will make 260 off rwkws on 98 with a good safe track tune with pretty good pull and grunt from 4,500rpm.

Anything more then that and you just move sideways and end up poorer for the experience

Now I am off to sook and think about why I am the only person on SAU who cant make an easy 25-35rwkws on E85 I think my 6boost and Turbosmart are coming off and think its time to just bite the bullet and man up and go back to my old setup described above

[STATUS]

Did it take the extra timing but make no extra power? it will tell you a fair bit. What where the exhaust temps doing too?

[Roy]

Who the f**k knows. Only gave it a quick fiddle this afternoon before getting the bigger injectors etc in there tomorrow and initial results were not encouraging with regards to the amount of boost and ignition meaning negligible change in power etc. So like everything with my car may need to be dragged kicking and screaming

[nisskid]

I love how the 20G makes more power at 4,000rpm then the 2535, and way more torque when you consider that whilst they seem pretty even the diff ratio is lower in the 20G setup.

fair's fair, kris was running the cams, exhaust manifold with external wastegate etc, mine still ran stock manifold, cams, internally wastegated and i was running a basic t-piece boost controller. fairly different setups, but yeh hoping for similar if not better results with a similar setup + e85

My 2c is if the head is off then give it a tidy up of casting and match port the thing. Give the head a shave and try to get a budget RB25esque 9.0:1 compression ratio out of the thing. If the engine is all together then don't touch a thing. Run the std inlet with a Greddy or OBX exhaust manifold and std cams. You will make 260 off rwkws on 98 with a good safe track tune with pretty good pull and grunt from 4,500rpm.

Anything more then that and you just move sideways and end up poorer for the experience

Now I am off to sook and think about why I am the only person on SAU who cant make an easy 25-35rwkws on E85 I think my 6boost and Turbosmart are coming off and think its time to just bite the bullet and man up and go back to my old setup described above

yeh mate, engine is together, not looking to do anything too extensive on this one, next engine yes, but put this engine back together only a year or so ago, so not gonna pull it apart atm.

i have a hks mainfold sitting there, so might just wack that setup on, leave the cams for now, and see how that goes.

[Roy]

Well the HKS cams Kris is running are similar to the Apexi cams I tried and its quite possible the cams he is running hurt response. But yes, granted the rest of the points are valid re manifold etc which on the bigger RBs may not make a difference but on the lil RB20 it seems a nice exhaust manifold can help that little bit with power and response. Kris runs my old Greddy manifold which whilst there are a few variables in my changing to a 6boost....the Greddy was every bit the equal of the 6boost and possible superior in outright performance.

If you have a HKS manifold then its time to Kando TD06-20G up If my memory serves me correctly Kris went from a 2535 to TD06-20G and was happy with the overall change.

[STATUS]

Who the f**k knows. Only gave it a quick fiddle this afternoon before getting the bigger injectors etc in there tomorrow and initial results were not encouraging with regards to the amount of boost and ignition meaning negligible change in power etc. So like everything with my car may need to be dragged kicking and screaming

HAHA busterd cars.... definitely know the feeling.

I fitted pressure fittings into the exh manifold yesterday so i hope to gain a few insights into whats going on with inlet/exh pressure ratio.

[nisskid]

Well the HKS cams Kris is running are similar to the Apexi cams I tried and its quite possible the cams he is running hurt response. But yes, granted the rest of the points are valid re manifold etc which on the bigger RBs may not make a difference but on the lil RB20 it seems a nice exhaust manifold can help that little bit with power and response. Kris runs my old Greddy manifold which whilst there are a few variables in my changing to a 6boost....the Greddy was every bit the equal of the 6boost and possible superior in outright performance.

If you have a HKS manifold then its time to Kando TD06-20G up If my memory serves me correctly Kris went from a 2535 to TD06-20G and was happy with the overall change.

yeh mate, will be grabbing one very soon, have a bunch of little goodies to go on from the cars im parting out. still haven't decided with ebc to go with, the blitz duel-sbc or the trust profec, thinking i might try all 3 different types i have on the dyno and see where it gets me.

[sav man]

Here is my dyno. Stock RB20 with RB26 inlet (short runners), and RB20 highflow (close to gt2871 core in RB20 housing)

You must be cursed roy

Edited May 26, 2012 by sav man

[nisskid]

Here is my dyno. Stock RB20 with RB26 inlet (short runners), and RB20 highflow (close to gt2871 core in RB20 housing)

You must be cursed roy

holy shit that's laggy

[sav man]

yes, yes it was. But it did drive a lot better than it looks it would

[nisskid]

yes, yes it was. But it did drive a lot better than it looks it would

yeh you would have had a similar powerband to me and kris as you ran it all the way to 8krpm.

[jdmser]

Roy,

I'm assuming the 260/8.8 were the Tomei procams and if so did you degree them to Tomei spec? I was running these when my engine was last together and heard that while the poncams can be dropped in that all of the procams need to be degreed. Are at least that's what I understood after translating a couple of Tomei Japans pages.

[Roy]

Roy,

I'm assuming the 260/8.8 were the Tomei procams and if so did you degree them to Tomei spec? I was running these when my engine was last together and heard that while the poncams can be dropped in that all of the procams need to be degreed. Are at least that's what I understood after translating a couple of Tomei Japans pages.

Apexi....and they were not degreed in as i have cam gears and we played for hours to see what characteristics we could get from them....end of the day they simply didnt work with my current setup

You can see above after some 60 dyno pulls trying different cam, fuel an ignition settings,,,put the std cams back in with old cam gear settings and bingo....wiyhin a few dyno pulls had more ;power everywhere,

Not to say others wom\nt be able to get cams to work. But my setup simply doesn't need them and i am told Apexincams are nowhere near as good as Tomei and HKS

[nisskid]

just had this come up on facebook, poncams and apparently played with pulley settings netted this: