2JZ head porting.

[BigMuz]

every1 in the states rave about these manifolds, they say theres nothing better than them

I thought you knew better than everyone else who has worked on 2jzs? So why would you care what American forum guys say about an off the shelf manifold- surely you have your own ideas and design for a better manifold?

[Billzilla]

TK, I suspect it might be a good idea to look at each of the four heads available - The turbo & NA 1JZ & 2JZ, as I believe they're all slightly different.
If you're going to do a good JZ head, I'd be picking the best one to start with.
For example. the 2JZGE NA head has much better exhaust ports than the 2JZGTE turbo head, but the inlet ports aren't as good.

[JZK25]

Yeah but can't seem to find the "good" ebay manifold for the gte

I am having the same problem with my mates JZX71 build. Got the engine and box delivered next day(a ride in Dennis' car the day before sealed the deal :D) but can't find a manifold like Dennis' on ebay. The damn things were everywhere when I didn't want one.

[2JZR31]

The damn things were everywhere when I didn't want one.

Yeah stuffs me what happened. The other type isn't to bad. You will need to spend some time with a die grinder and probably get it internally sand blasted to have ease of mind. It just suck's that the other type was cheaper and didn't have as many probs.

[21OWA]

I thought you knew better than everyone else who has worked on 2jzs? So why would you care what American forum guys say about an off the shelf manifold- surely you have your own ideas and design for a better manifold?

haha your a funny fu<ker

as far as im concerened, theres no manifold better than the Full Race manifold but theres no way id eva pay that sort of money for a manifold!
Kyles manifolds are great and are a good price
but im getting the guy thats doing my conversion to do my manifold and the collector is from Leigh at Extreme Turbo Manifolds

i care what the US guys say because they know ALOT more about the 2J than people here in Aus and have done ALOT more with it
Pretty much all my parts have come from SP or Titan

[JZK25]

Can't wait to see the grudge match between 21OWA and Ezekial.
Two awesome cars according to the owners.
Should be interesting.

[Norbie]

TK, I suspect it might be a good idea to look at each of the four heads available - The turbo & NA 1JZ & 2JZ, as I believe they're all slightly different.

Yeah, it would be great to see a direct comparison of all 4 heads, before and after porting. There's so much BS out there about which is best (witness all the "1.5JZ" crap people go on about), sorting out fact from fiction would be very useful indeed! I have a feeling the 2JZ-GE head may be slightly better than the 2JZ-GTE head but I have no way of knowing for sure, there are too many armchair experts out there who will feed you shit without backing it up with real comparisons.

[BigMuz]

Why would they cast different heads for the same engine if there is no performance advantage. We're not talking about Rover; this is Toyota- they do engines..

edit Not saying it's not right, but it seems crazy to me if it is for no real clear cut advantage. Maybe compression ratio/ combustion chamber is different?

[2JZR31]

I think the chamber volumes are very close. (not 100%, but there is a thread somewhere where someone worked it out). Its mainly port design. Toyota loves to "perfect" the heads to each application.

[Norbie]

Port design is quite different between the GE and GTE heads, it's clear Toyota were aiming for maximum exhaust velocity with the turbo engines to get the turbos spooling up quickly, and it seemed to work quite well for them.

As for why the 1JZ and 2JZ heads are different, I have no idea? Toyota do strange things sometimes.

[2JZR31]

Well they are different capacities and one is newer.

[Billzilla]

There's so much BS out there about which is best (witness all the "1.5JZ" crap people go on about), sorting out fact from fiction would be very useful indeed!

This is why I picked that particular 7AFE head I'm using on the new engine I'm building. Everyone knows FE heads are rubbish, so they won't work ...

[BMWTurbo]

A mate bought a manifold from Just Jap and it's the best 'chineses' manifold I've seen for 2jzgte's... Think it was $350 or something.

Had braces V-band gate flange etc... nice bit of gear...

[Reaper]

Hello PF'ers,

I'm a long time listener, first time caller - hah! not really, but have browsed by a few times. Just posting up some details as my car is donating it's head to this worthy cause. A big thanks to TK for such a generous offer & to the mighty SuperCrown for putting me onto this thread.

The car's specs are >>>

1993 GZ TT auto aero with 2JZ-GTE (non-vvti)
GT4088R with 0.95 A/R hotside (1 click up from std)
HKS manifold
HKS 50mm 'RaceGate'
3" flared to 4" dump, then re-flared back down to full 3" catless Blitz zorst
Sard 800's on Sard top feed rail (recent change)
Bosch 044 internal setup (recent change)
Koyo ally radiator
DNA 80mm FMIC
Standard - intake plenum/tb/cams/valves/cam gears/ignition
AEM ecu
MV Automatics built auto with hi-stall (3200 flash speed)
Blitz i-Color SBC boost controller

Car currently runs 23psi on 98RON PULP everyday and has laid down 307rwkw on a Mainline Dyno on an unlocked auto.
(Note: dyno chart refers to 'octane' - we did have octane booster in the fuel that day but found no extra timing could be added over normal 23psi settings, it did quell knock some but had no performance benefit in our tests)

Mainline's run about 10% less than DD (as shown by previous back to back comparison done by myself). Estimated crank horsepower currently is around 600hp. So in everyday Dyno Dynamics language (if this car's auto were locked up) this car would put down about ~360/370 rwkw in current form.

Dyno charts attached here show the 'baseline' that the car will be working off. At that time I was running a Sard internal pump and Sard 650's on the OEM rail. I have only changed to 800 top feeds and a Bosch 044 since then. So no tuning change, only better fuel capacity really.

I have spoken to Tony about what we are going to do. He is going to perform his black and mysterious arts on the head and I am going to just put it all back together without any configuration change. I will go back to my usual dyno joint and get follow up dyno figures. After that initial dyno I expect to do some tuning to make use of the head work so will put that subsequent 'tuned head' dyno up also BUT I will stick with the same type of fuel and boost level to aid a fair comparison.

Expected results are a bit sketchy as this is obviously new territory but the current guess is that spool could drop by 600 - ?800 rpm. I guess Tony could chime in here to give more of an educated guess. The figure I always ask people is what rpm do they cross 1 bar? Currently my car crosses that figure at 3600. Therefore with the new head I would expect to see this drop to 3K or below - here's hoping.

Seano (SuperCrown) and I have been meaning to work on this car's timing in the mid-sections of my maps for quite a while now so with some road tuning I would also expect to drop this final spool figure even more. Currently the lower sections of my maps feel very mushy so I think there is quite a bit of gain to be had down low re: throttle response/ mid-range.

This will take several weeks I might add as TK needs a couple of weeks, I will need perhaps 1 or 2 myself to get it all back together.

Note: I may well elect to upgrade the valvetrain to high speed springs and titanium retainers but that should have no performance impact on the result I expect ie. now is a very good time to do this.

Note2: You can see the SuperCrown !! in the background of my dyno shot - fookin weapon it is.

Cheers, back soonish,
Gaven

PS - I wanted 'Reaper' when I registered but someone else has it BUT has not been on here in 2 years. Who can I contact to have that username reassigned i.e. the acct is obviously defunct - 2 years is a long time on 'teh InterWeb'.

[BigMuz]

Excellent stuff mate and welcome. Looking forward to seeing the results.

PS laminating your dyno sheet is a bit weird :D
PPS Having your car's pic in the background even more so :D

What do you use the car for? Run it down the quarter? 12s at what mile an hour?