Osg Rb30 Vs Hks Rb28 Stage Iii

[khezz]

I am at a loss here guys. any help will be most welcome. I won an r32 GTR this will be the last car ill get to build up so I am going all out. i want to use it for curcuit, hill climb and if all goes well go into the Targa west next year. I would like a reliable 800hp at the wheels and initialy looked at the OSG rb30 and whent as far as ordering one. Than I got a call from the supplier who asked if I would consider the HKS stage III 2.8l kit. His orgument was that it revs better, costs less (inc build and all of the bottom end) and can produce similar power to the rb30. I have been pushed and pulled either way for the past four months I just need some one to give me the cold hard facts. Its very hard to talk to supliers cause they'll push what they sell and i can not afford to make a mistake. Until I order the engine parts I can order anything else and I wont the car on the road by this time next year. Once again, any help will be most welcome.

[manage13]

i want to use it for curcuit, hill climb and if all goes well go into the Targa west next year.

Both kits are good but capacity rules I'd go the OS 3ltr.

Edited August 30, 2006 by manage13

[khezz]

i thought so to but than i was told that the rb30 is safe for aobut 9000rpm where the stage 3 HKS is ok at 12000rpm. is that true or is it a pipe dream? Take into account that all supporting hardware and software that matter will be top notch. best of everything. but like i said i cant build it twice. cant afford to.

[paulr33]

are you allowed to change to a 3 litre? what are the targa rules?

you shouldnt need to rev the rb30 to 9 grand to make good power.

revving high doesnt make a car magically fast, average power will

the power the rb30 makes at 7k the rb26 makes at 9250.

have a search on the r33 rb30 thread.

the rb30 build is always cheaper than a big rb26 build

[Beer Baron]

the power the rb30 makes at 7k the rb26 makes at 9250.

the rb30 build is always cheaper than a big rb26 build

OSG RB30 is not cheaper than an RB26 build. The bottom end alone costs around $20K... and I'm not sure what the relevance of comparing a RB30 to an RB26 is? we are talking an OSG RB30 kit compared to a 2.8 stroker (no block spacer though). so comparing an RB30 to a standard bore and stroke 26 is not really relevant.

I have not personally used either but if it were me, with a similar goal, I would chose the HKS step 3 2.8 kit. Their parts are top notch and the results from japan with people using the 2.8 are very promising. Also, when nissan were running in GT500 with an RB what capacity did they go for??? that's right 2.8. Most of the big name circuit and time attack GTRs in Japan at the moment seem to be going for a 2.8 kit of some kind, and plenty with the HKS kit. The OSG RB30 seems to be more suited to drag racing.

[khezz]

i see your point mr baron. as for the laws on the targa, it comes down to the class. I am not going to compete i just want to be in it as a driver. There are classes for all cars, a few years ago we had a 760hp porche 3.6l and it had a class. Looking at the japans gt races the 2.8l choise also came down to the amount of boost they were alowd to run on them. as for drag, the fastest cars eg rh9 dont use the 3l kit. but as a general rule, you do seem to be correct. i posted a similar link ona uk forum and people there seem to lean towards the HKS kit to.

[R31Nismoid]

600rwkw for a hill climb/circuit car? :sorcerer:

Why do you need that much power for that application?

For every cent you spend on the motor, you'll need more than double to cover the areas of suspension/breaks/gearbox/clutches/tyres etc etc as with that much power, you'd wanna have all the other $$$ spent first.

That said... do you want response or more RPM?

[Roy]

It may check to see the GT class rules with regard to means of induction, displacement and weight to see if that lends any light to the Nissan 2.8L thing...it could have more to do with the regs then any mystical/ideal displacement for grunt.

I would go the OS myself. There are plenty of amazing cars running them. Sure they present a few dramas with many of the bolt on turbo kits and IC kits no longer being bolt on because of the hieght difference, but the additional cost to allow for this is nothing compared to the total cost of what you are undertaking.

All the talk of revs. Hell even if the engine was built to pull those sort of revs...keep you r money in your pocket and save on the wear and tear and dont rev it that hard. I cant see the RB30 being a lazy motor. There are longer stroke sixes out there that rev beautifully, no reason the RB30 cant from a mechanics standpoint

800hp is sh1t loads of grunt, do you really need that much? Dont forget you have to keep your coolant temps, oil temps, diff and gearbox temps all under control...on a circuit / tarmac rally car you could find yourself working very, very hard keeping them in check

[rb26s13]

i remember reading somewere that osgiken guaranteed there 3litre kits to 10,000rpm and 1400hp?? dont know were i read it but yer..

[Faid]

i was looking into th os giken buy once but i dropped off it. the HKS step 3 2.8 is far better, have you ever seen how one of those cars rev, here in my country there is one other GTR with a HKS step 3 2.8 kit, its used for dragracing but when the car takes its revs ist sounds like a throttle up of 747. and with the right harmonic balancer you should be able to go into the 11K maybe 12K. but to do circuit rally that sort of things, i dont want to see the amount of coolers youd have to place on the car, youd need at least a tripple core alu radiadtor, a oil cooler at least 19 rows, transmission cooler, and if you an find it (a big if) use the differential coolers they used on the GTR Z tune. i wish you loads of succes and keep us posted on ur progres love to hear what youve decided to do

[Blitz]

For circuit, 2.8 stroker kit.

[Mik]

I'm going to disagree and say that the Giken would be better than the HKS stroker for circuit.

The HKS kit (step 3 anyway) is designed to be revved very hard and used with huge turbos...I can't see why you would possibly want to rev anything that hard around a circuit...and besides, it just wouldn't last.

Where as the Giken bottom end with biggish cams (maybe step2) and say 2835R turbos would have a fat torque curve and would last a lot better because you would never need to rev it past 9k.

[khezz]

I realise the costs of all the support ssytems i will need to put in place and believe me i have talked to alot of poeple here and uk and japan about them. That part is not a huge problem. As for my purpose, Like i said this will be my last one. I want the broadest possible power band. I am changing to a 6 speed gearbox. I have heard of the OSG being "safe" for 1400hp and 10 000rpm but i have not heard of any one proving those figures true or false for that matter. I have seen the stage 3 kit to pull over 1200hp and over 11000rpm. and make great use of a twin hks 3240kit. As for maintanance, no matter what you get, if you drive it hard enough and dont look after it, it will break. Thanks for the info so far. Just for peoples interests, it looks like i will most likely go for a single turbo from ITS, they have shown simply amazing results in the US.

[blk180]

I would go the OS kit if i had the money and was building a track pig. Dont they build and sell full crate(bad spelling) engines.

Also 2.8 lt kit is not cheaper ask how much it cost to get the head work to Rev to 12000rpm compared to 10000rpm.

Brad

[khezz]

you know in all of this i didi not think of that, ill have to have a look. Yes the OSG does come all put together ready to go. but the parts for the stage 3 kit cost about 15grand less than the OSG kit.

[Sydneykid]

I realise the costs of all the support ssytems i will need to put in place and believe me i have talked to alot of poeple here and uk and japan about them. That part is not a huge problem. As for my purpose, Like i said this will be my last one. I want the broadest possible power band. I am changing to a 6 speed gearbox. I have heard of the OSG being "safe" for 1400hp and 10 000rpm but i have not heard of any one proving those figures true or false for that matter. I have seen the stage 3 kit to pull over 1200hp and over 11000rpm. and make great use of a twin hks 3240kit. As for maintanance, no matter what you get, if you drive it hard enough and dont look after it, it will break. Thanks for the info so far. Just for peoples interests, it looks like i will most likely go for a single turbo from ITS, they have shown simply amazing results in the US.

These are drag racing numbers, TOTALLY irrelevant for circuit or targa use.

Forget about them, they mean NOTHING for what you are going to use the car for.

You will NOT find a gearbox, clutch, diff or drive shafts that will suite a circuit race application with that sort of power and/or rpm. You will loose more races due to unreliability than you win due to the extra horsepower.

The lag and shear lack of throttle response will make the car almost IMPOSSIBLE to drive around corners at anywhere near the G forces necessary to be competitive.

The fastest GTR’s around circuits have 600 to 700 bhp, the faster ones closer to 600 than 700. Check around, look at the lap times, look at the race results.

Keeping the above in mind the answer is ……………

IT DOESN’T MATTER

Any decent 2.6, 2.7 , 2.8, 3.0 or 3.1 litre RB will do the job just fine. Apexi, HKS, OS Giken, Trust etc etc they will all satisfy your requirements.

Turbo and camshaft selection to match the gearbox and diff ratios is far more important than a few extra cc’s. So just PICK a bottom end and get on with the important stuff, safe in the knowledge that you can’t make a bad decision whichever one you choose.

cheers

Edited August 31, 2006 by Sydneykid

[Mandingo]

Fly to japan and buy a mines car. problem solved and you'll win targa

2.8 FTW

Edited August 31, 2006 by Flipmo

[khezz]

I do own a mines car, LOL it was a test bed for them. They left all the suspension work in it and the roll cage. plus the clutch. the body has all the extra re-inforcing to. As for hp over drivability. The fastest GTR's around tsukuba this year were all around 800bhp with one being 1020bhp. AS i wrote earlier, I am after the biggest power band possible. I am leaning towards the rb28 as it seems to be good balance between revs and cubes. As for head work costs, the saving i make on the rb28 stage 3 will coveer the extra work needed to rev it. But thanks for bringing it up. realy, thank you. Plus I am notr after winning races I am after a final project. Shit load of fun. I used to have a 600hp xr6t and all i did was dream about an 800hp gtr. SO now i have a chance, I am getting it.

[Cool Hand Luke]

I cant see you being able to do a targa with 1000+fwhp and 12,000revs without a rebuild along the way.

Have a look at the CRD GTR and the sort of mods it has to rev that high. And they were still stretching their valves on short drag runs.

I'd personally go with what sydneykid said. He has a lot of experience in this areas, and its not one you would want to make an error in.

Edited August 31, 2006 by Cool Hand Luke

[fEkuaR]

I do own a mines car, LOL it was a test bed for them. They left all the suspension work in it and the roll cage. plus the clutch. the body has all the extra re-inforcing to. As for hp over drivability. The fastest GTR's around tsukuba this year were all around 800bhp with one being 1020bhp. AS i wrote earlier, I am after the biggest power band possible. I am leaning towards the rb28 as it seems to be good balance between revs and cubes. As for head work costs, the saving i make on the rb28 stage 3 will coveer the extra work needed to rev it. But thanks for bringing it up. realy, thank you. Plus I am notr after winning races I am after a final project. Shit load of fun. I used to have a 600hp xr6t and all i did was dream about an 800hp gtr. SO now i have a chance, I am getting it.

You have to much money.