Rb Head Vs Jz Head

[TurbostyleR]

yeah I have been told there are some fairly substaintial gains that can be had from SR20DET heads being ported. The first thing i did with my built motor was to get 1mm oversized exhaust valves which would help a little in the flow department - as I was too scared to lose any low down torque from major head porting lol...

Thanks once again for your help Daniel...

[Sydneykid]

sydney kid, you never cease to amaze me with the shit that comes out of your brain and onto this forum.

Strangely enough some of the stuff that you post doesn’t amaze me at all

MPH is a direct result of power, there are other measures but MPH is a bloody good measurable realisitc measure, circuit times and ets aren't.

I know that you know its average power to weight not max power on its own. Why do you persist in promoting something that is so obviously wrong?

fact remains, its a known fact toyota engines JZ series will take far more power for far longer periods of time than RB engines. that is fact.

That’s you opinion not a fact, JZ’s cost more to make the same power as RB26’s. We have had this discussion before, whether I spend $1K on stronger rods or $1K on an inlet manifold is irrelevant, it still costs $1K to fix the problem. Your problem is you think not spending money on the inside of an JZ somehow makes it superior even though you spend more on the outside fixing the JZ’s shortcomings in that area.

one of the main reason i built my car was to go race GTST's and flog there arse

I have looked long and hard at the ANDRA Sport Compact Records and I can’t find one JZ at the top of any list. A couple of RB’s though. I have also had a look at the HPI Radial challenge and I can’t find one JZ at the top of that list either. A few RB’s on top there as well.

but its people like you SK that make all other skyline haters hate skyline owners. many toyota guys get on this forum

The problem is I currently work on more Toyotas at race meetings than I do Skylines at the moment. Perhaps that’s the problem.

i apologise ahead of time if my comments have offended anyone.

Eh, a bit of venting never hurt anybody, as long as it is done in the right spirit. Plus it would be a very boring forum if we all agreed with each other all of the time.

cheers

[DoughBoy]

How does VVT give larger CFM readings? AKAIK on RB's, SR's and 2J's the VVT doesn't activate a third inlet valve, change the port size, manipulate runner size or length, or do anything other than change the lobe center on the camshaft.

Edit: Also your flow readings.. are they an average? What lift? What pressure? What measuring equipment?

[Beer Baron]

ok the name calling and bickering stops now. this thread has great info in it, but it's not a debate on whether or not mph=power, or is rb more reliable than jz or does jz power faster cars than rb or whatever.

i'm inclined generally to just let things run their course but the fighting is wrecking and diluting the thread. I'm not singling anyone out, but the next person to start up with the arguing will cop a warning. everyone in this argument has had their say now, so lets just leave it be.

any questions on flow of RB vs JZ heads etc or info is welcome of course. so bearing that in mind lets continue shall we?

[chris davey]

Strangely enough some of the stuff that you post doesn’t amaze me at all

I know that you know its average power to weight not max power on its own. Why do you persist in promoting something that is so obviously wrong?

So 2 cars, equal weight, trans, driver, suspension etc. One has 450rwhp from 4000rpm to 7000rpm. Another has 550rwhp from 5500-7000rpm. Are you telling me that the 450rwhp car will out trap the 550rwhp car?

That’s you opinion not a fact, JZ’s cost more to make the same power as RB26’s. We have had this discussion before, whether I spend $1K on stronger rods or $1K on an inlet manifold is irrelevant, it still costs $1K to fix the problem. Your problem is you think not spending money on the inside of an JZ somehow makes it superior even though you spend more on the outside fixing the JZ’s shortcomings in that area.

Difference is that the RB rods are a necessity wheras the stock inlet manifold on a 1 or 2jz or fine unless you are wanting to squeeze every last HP out of your engine and you want to push the torque curve higher up the rev range.

I have looked long and hard at the ANDRA Sport Compact Records and I can’t find one JZ at the top of any list. A couple of RB’s though.

4wd vs RWD on street tyres. Hmm...

I have also had a look at the HPI Radial challenge and I can’t find one JZ at the top of that list either. A few RB’s on top there as well.

Negative it seems.

Carlos: 10.04@150mph. 2.23 60 ft.

[Beer Baron]

am i writing in invisible ink?

edit: in case I wasn't clear debating about things unrelated to RBvsJZ heads and flow figures etc is going to stop. you are now just debating the same point over and over. if you want to argue the toss with sydneykid pm him and do so.

[chris davey]

started post prior to you posting.

I am done. I give no fark anyway

[Beer Baron]

enough whoring this thread bitches.

http://www.skylinesaustralia.com/forums/in...p;#entry2329179

[DoughBoy]

Hah put my post in the fag section please, it belongs there.

[DoughBoy]

Err I meant drag

[Beer Baron]

done you big fag.

[EXP19]

As for flow numbers here they are:

Rb26 (std) Inlet: 148cfm Ex: 105cfm

Rb25 (std) Inlet: 136cfm Ex: 98cfm

2JZ (std) Inlet: 139cfm Ex:121cfm

1JZ (std) Inlet: 134cfm Ex: 115cfm

very interesting figures there

also note that the 2J has a lift of 8.61/8.79mm while the 26 im pretty sure is only 8.1/8.2mm??

also, a guy in the the states flowed the 2J and 1J heads and got significantly higher figures than that!!

was done at 400lift (10.16mm) but not sure at what inches of water it was done at tho

his figures read:

std 2J as follows

238@400lift intake

154@400lift exhaust

std 1J

215@400 intake

133@400 exhaust

your 2J figures give a percentage of 87% while his gives 64.7%

granted his tests are done at alot more lift which will give a higher reading

cheers

Troy

[DennisRB30]

very interesting figures there

also note that the 2J has a lift of 8.61/8.79mm while the 26 im pretty sure is only 8.1/8.2mm??

also, a guy in the the states flowed the 2J and 1J heads and got significantly higher figures than that!!

was done at 400lift (10.16mm) but not sure at what inches of water it was done at tho

his figures read:

std 2J as follows

238@400lift intake

154@400lift exhaust

std 1J

215@400 intake

133@400 exhaust

your 2J figures give a percentage of 87% while his gives 64.7%

granted his tests are done at alot more lift which will give a higher reading

cheers

Troy

Just dug this thread up. I didn't expect to actually find any more decent info, just more bullshit!

Thanks Daniel for providing the figures. Very interesting.

[2rismo]

but not sure at what inches of water it was done at tho

his figures read:

granted his tests are done at alot more lift which will give a higher reading

Which makes a comparison impossible.

[eXquiSit]

Any further updates?