Stroker Vs. Hybrid

[R31Nismoid]

I still don't understand if "money isn't a problem" why on earth you are using a R31?

Same reason that chick wants to drop a 40k V8 or whatever into a R31

tbh the Spool kit is something I'd steer clear of, most of the kits I've seen use I-beams but they use H-beams, and there was a fair bit of clearancing at the bottom of the combustion chamber. I did look into those RIPS motors..

and lol i didn't actually say money is no object, the budget is $20k for a running, driveable car (though massive power and driveable on street rarely go in the same sentence tbh)

i thought about the RIPS, it revs to 9K, I could get a Nitto stroker kit with an RB30 block for the same rated at 1600hp and 12k rpm max though?

First of all, making comments about I & H like that, clearly you do not know what you are talking about.

The debate will run forever about which is best.

Its application dependant, simple as that

hmmm all valid points, and yeah the whole thing about RB cranks is right, I think that Nitto thing may end up being the way I go with an RB26 head, those stroker kits are nuts with a 12k rpm limiter, and means I can run a retardedly oversized turbo haha

Again no ideas. What are you worried about cranks for?

20k budget wont even get your head to 10,000rpm. Let alone 12,000

So I wouldn't be getting too excited on which stroker etc.

Realistically to even sit @ 9,000rpm reliably your budget has already been blown out of the water before you start as there is probably 5k in the head alone.

20k on the street/running is as simple as a 25/30 with a mild freshen up of the bottom end etc.

Otherwise you go chasing super big power and RPM everything from the gearbox to diff & driveshafts needs attention. Then there is getting it to the ground etc etc. Just in driveline you'd be looking at the 8-10k mark.

[jangles]

tbh the Spool kit is something I'd steer clear of, most of the kits I've seen use I-beams but they use H-beams, and there was a fair bit of clearancing at the bottom of the combustion chamber. I did look into those RIPS motors..

and lol i didn't actually say money is no object, the budget is $20k for a running, driveable car (though massive power and driveable on street rarely go in the same sentence tbh)

i thought about the RIPS, it revs to 9K, I could get a Nitto stroker kit with an RB30 block for the same rated at 1600hp and 12k rpm max though?

like nismoid said, and i said before you posted this.

a Nitto stroker is out of the question.

youre looking at 15k for the 3.2 assembled with oilpump,sump etc..(or external pump)

because youd want 2-3k worth of block prep if youre looking to utilize that kit.

30k would get you a 3.2l long engine...then you can use your 20k to buy the bolt on bits.

then you'll need a clutch,gearbox.... its really just pointless for you.

build a 26 or a 26/30, youre saving yourself 5k just for not having a stroker crank.

10k for the engine, 10k for the bolt on parts (turbo setup, fuel system, ecu, tune...if u shop wisely.

and i'll also add, that a 3l bottom end was an alternative to stroking a 26, so its still a stroker motor if you want that

Edited February 16, 2011 by jangles

[N1GTR]

Lol fattox

If H beams are so bad there's a lot of manufacturers that you'd better go and tell!

Also, are you going to have 1600hp?

Are you going to spend the mega bucks to allow you to spin it to 12,000rpm safely?

Even 9000rpm is a lot for a street driven car. A well matched turbo to suit whatever bottom end you go with will make it a fast car. No point having a T51RSPL that comes on at 6000rpm when the car next to you has a responsive and linear powerband as that car will be further down the road by the time you bring it on between corners/sets of lights.

It's just plain fkn stupid to buy something based on numbers which are unrealistic for what you're going to use it for.

Sure all the parts in question are quality etc and lots of supporters for all different brands but FFS go talk to a machinist with experience and listen to what they have to say

[Justlikemusic]

This is just going to be a dyno-queen?

Initial cost of R31... what, $1k?

If it isn't... what brakes are you using the on 31? $2k+ right there DIY

Then all the other ancillaries such as rims/tyres/suspension is going to cost you another $3k on the cheap

Turbocharger in itself will cost you over $1k

Exhaust system to suit big hp is another $1k

Gearbox to hold that power? R33 manual box with all the crap fitted (not sure about tailshaft interchangeability) $1k

Injectors? $500+ for some used big 700cc+

If you do stuff on the cheap you might be able to get away with $20k and all the labour yourself... I'd buy a R32 GTR for that price and have a reliable daily, track weapon and you can get well over 350rwhp with them with stock turbos. I had two R31's and as much as my heart is with them... and I HATE my whale R33, I still have to say the R33 is such a nicer car to get around with.

Still want to change to an R32 though... but I have no RB20 love =(

[jangles]

This is just going to be a dyno-queen?

Initial cost of R31... what, $1k?

If it isn't... what brakes are you using the on 31? $2k+ right there DIY

Then all the other ancillaries such as rims/tyres/suspension is going to cost you another $3k on the cheap

Turbocharger in itself will cost you over $1k

Exhaust system to suit big hp is another $1k

Gearbox to hold that power? R33 manual box with all the crap fitted (not sure about tailshaft interchangeability) $1k

Injectors? $500+ for some used big 700cc+

If you do stuff on the cheap you might be able to get away with $20k and all the labour yourself... I'd buy a R32 GTR for that price and have a reliable daily, track weapon and you can get well over 350rwhp with them with stock turbos. I had two R31's and as much as my heart is with them... and I HATE my whale R33, I still have to say the R33 is such a nicer car to get around with.

Still want to change to an R32 though... but I have no RB20 love =(

that there is the reason im guessing he doesnt buy a R32 GTR,

because he wants to build a motor for his R31,

if you were to buy a R32 you'd put a RB25 in it

[Tony de Wonderful]

Hey guys,

What does everyone think in regards to going with a hybrid motor aka rb25/30, or going with a stroker and rb26 head?

The main build plan is just for a dirty old r31 with a big dash of sleep =D then take it to dyno days and snap ridiculous boost into it, see how well it takes it

Myself building it, with a good mate who's a qualified mechanic (and knows RB's pretty well)

Opinions? I'm not overly a fan of the rb25/30, the plan was a stroker with rb26 head as the 26's love revving more, but i'm interested to see what people have to say?

2JZ?

/end of thread.

[Nee-san]

True men don't kill coyotes and they certainly don't put RB25's in R32's !

[Tony de Wonderful]

The RB25 (non NEO) head is very understated. Bigger ports than a 26, has VCT. The only thing that lets it down would be the hydraulic lifters if you are planning on revving it past 8500rpm.

Won't cost that much to chuck some 2nd hand solid lifters in there surely?

[Rolls]

VCT is the f**king shit, my controller died the other day for a few hours till I could rewire it, felt like I was driving a 20 again.

[Beer Baron]

fck. I didn't know H beams were bad? I better tell tomei to stop making conrods. their H beams have taken up to 200hp PER CYLINDER but I guess 1200hp is not much when you're after a 5 litre RB engine that can rev to 15,000rpm. would love to post more but want to get home to remove the tomei h beams from my engine before it blows. maybe I can replace them with some Chinese made I beams which are bound to be superior?

[FineLine]

fck. I didn't know H beams were bad? I better tell tomei to stop making conrods. their H beams have taken up to 200hp PER CYLINDER but I guess 1200hp is not much when you're after a 5 litre RB engine that can rev to 15,000rpm. would love to post more but want to get home to remove the tomei h beams from my engine before it blows. maybe I can replace them with some Chinese made I beams which are bound to be superior?

Just to put your mind at rest I'll take those shitty old h beams off your hands baron.

[Rolls]

What are the main reasons manufacturing wise to go H or I beam? pros and cons?

edit: a quick google says tensile vs loading, so basically high rpm suits one design and high pressure lower rpm suits others.

Edited February 17, 2011 by Rolls

[Nee-san]

What we need to do is to put them into ANSYS for a nice FEA bashing so people can stop crying the tears of a small mexican child over which section is better.

[Beer Baron]

Just to put your mind at rest I'll take those shitty old h beams off your hands baron.

mate, you are always there for the little guy when needed. I'm going to ring up all the people I've bad mouthed you too and tell them i've changed my mind. tomei h-beams in the post.

in all seriousness the debate between H vs I beam rods can and will go on for ever. what makes it tough to rule one design better than the other is different manufacturers use different materials. so if comparing a cast I beam to a forged H beam which do you think is stronger? on top of that there are variations in every manufacturers interpretation of an I beam design and an H beam design so even among the same 'type' the designs vary quite a bit. a little more meat here and a bit less there and suddenly the strength of the rod is greatly affected.

there are a few important things with rods.

material. what grade of alloy is used?

forging (there is a vast difference between the quality of forgings between manufactueres - I won't even mention cast rods as I don't know of any aftermarket company making any for RB engines)

design (I don't mean H beam or I beam, I mean the design of the rod, where is the weight concentrated? where is the rod weak? where is it srong? is there strength in all the right places?)

Track record - who has used these rods before? what kind of power are they handling? how are they performing in competition? how many sets have they sold?

quality control - are they all the same weight? what kind of tolerance are they allowing for the size of big end and little ends? how good is the finishing?

after all those considerations then maybe you can think about I beam vs H beam or throw in X beam too if you're feeling frisky.

anyway, some info on tomei H beams. there is a small section on why they make H beams over I beams but the fact is regardless of the type they are great rods and proven many times over to handle very high cylinder pressures in engines up to 1200hp in a 6 cylinder.

http://www.tomei-p.co.jp/inf/pdf/121_AE-11x17.pdf

[bigmikespec]

What we need to do is to put them into ANSYS for a nice FEA bashing so people can stop crying the tears of a small mexican child over which section is better.

Yeah I am sure an accurate result will be had

Two engines exactly the same one with "H" one with "I"... keep making power until bang then assess the damage.

[Nee-san]

Destructive testing definitely has it's place, but when you model something in FEA you have the opportunity to really control the variables involved in the whole simulation process.

For example, you could develop a 5 point test and test 5 different parameters of each rod and how the two samples respond to stresses etc etc, but your are able to do this in a fully controlled computer environment.

Now sure, simulation has it's flaws but it is massively widespread in engineering these days and is always going to be better then "My H beam rod can take 1337 more kebabs of power then your I beams bro, because they have extra tabouli"

[sneakey pete]

One has to remember of course that FEA is only an approximation. However, its an approximation down to such a fine degree that' its "good enough" for practically any application. (of course real world testing is needed to make sure you've done your calculations right). The hardest part about FEA isn't putting in the object (dead easy), or loading it up with the correct conditions, its understanding the results, when to use them and when not to. (eg the 10th natural frequency of an object calculated by the FEA is most likely to be ridiciliously wrong).

In regard to rods themselves, my unexperienced but logical guess would be to buy pistons to suit your application. Sure xx H beams might be able to handle twice the power of yy I beams, but if you only want the sort of power that yy can handle.... get yy.

Edited February 18, 2011 by sneakey pete

[FineLine]

mate, you are always there for the little guy when needed. I'm going to ring up all the people I've bad mouthed you too and tell them i've changed my mind. tomei h-beams in the post.

http://www.tomei-p.co.jp/inf/pdf/121_AE-11x17.pdf

Just takin one for the team mate.

[Beer Baron]

make no mistake I was not advocating H over I beam. my point is that in the real world were we have plenty of I beam and H beam designs that will take up to 200hp per cylinder just chose whatever you want. my whole point was the bloke writing off H beams as rubbish was wrong. there are as many good H beams out there as I beams. Some of the BEST rods out there are H beams (like the tomei ones above). coincidentally the tomei rods are pretty cheap out the US these days with the strength of the AUD. $1200 USD for a set of tomei rods tells me I will be using them next time (that's if the current ones ever need replacing....). they have some nice design features like the shoulders, no nuts (thread cut into rod instead), little cuffs to ensure god fitment of the two halves and the fact that they are forged as two seperate pieces instead of 1 piece that is then cut in half.