turbodremz

iTrader: (18)

Ok as some of you know I have hit the second leg of my na-t build, but am starting to plan and research the third and final leg of the build. Basically I am shooting for a 500+ rwhp daily driver, so reliability is a must. I have plans to build another GE block with some nice pistons/rods/ARP hardware, but would like to scrap the stock GE head and distributor.

So naturally first thing that comes to mind is going with a 1JZ head, non-VVTI, with some mild cams, and if possible using the stock 1JZ ecu. Just wondering if its even worth the time/money to consider this, or just stick with the stock GE head and push the current setup.

I know with the 1JZ head, I will have a little more revving power/range, but compared to the stock GE head, is it worth the money? Or just use the money and build the GE head? Would the stock 1JZ ecu even allow me to hit 500+ or is a standalone still the only option, or can it even be done with the stock GE ecu, or a 2JZGTE ecu on the GE?

Need some "guru's" opinions/suggestions on the head/ecu choices listed above.

Stick with the GE head and ecu and push it
Go with the 1J head and 1J ecu
or stick with the GE head and 2J-GTE ecu?

I dont really want to do a COP conversion cause to me its just seems like a PITA, so if I stick with the stock GE head, the stock ignition stays..with proper support such as MSD

jonboyb

While I can't give alot of insight to all your questions, I can tell you what I know about a 1.5GTE. First thing to note is a compression bump from the 1JZ head. Not sure why but I assume it's the larger quench area on the 1JZ head vs. a 2JZ. On a fresh rebuild with 2JZ-GTE pistons and a stock TT 1.3mm HG I'm hitting 192psi per hole at 4000 miles in. While the bump makes tuning more critical from the high compression, it's really nice for drivability and spooling a big turbo (76 in my case that hits WG 21 psi at 4700).

Second....the 1JZ ECU. It came with 380cc injectors so in theory piggybacks such as MAP-ECU and SAFC's can control roughly double the injector (ie. 760cc or 75lb). Now in reality I've made 1000cc's work with an APEXi NEO out of necessity by lowering the fuel pressure. Not the right way....but all I had to work with at the time. I have some 75lb injectors ready to go now.

And regarding hitting 500+ whp with a 1JZ ECU the answer is definantly yes

turbodremz

iTrader: (18)

Thanks Jon that really cleared up a lot. Now I have some important decisions to make. Any down sides to the 1.5J other than the compression bump that I should be weary of?

jonboyb

Honestly....I have no complaints about the 1.5. I actually prefer it over my 2JZ-GTE Supra as it just feels "peppy" in comparison but that's likely just the higher compression. Certainly more grunt than a straight 1JZ too. The big disadvantage to you is going to be finding just a head first of all.....I've been looking for some time, and all the tidbits you need there (intake, sensors, exhaust man, etc.). Then the harness/ECU swap. Best bet would be to buy a complete JDM engine set and sell the bottom-end and tranny

good2go

iTrader: (6)

IMHO, I just don't see how this statement doesn't ultimately include a good standalone

99SC42

iTrader: (44)

Damn that's a tough one Chris, Pm me i got some for you.

turbodremz

iTrader: (18)

Because if you read carefully, not everyone has excellent results with a standalone. I have been having good luck with absolutely no issues using an SAFC2 so far, and now with the MAFT Pro and a few more parameters to adjust I am expecting even better results using just a piggyback system. Pair a good piggyback with an OEM ECU and have it tuned properly, reliability shouldnt be an issue...otherwise you wouldnt see so many MK4 Supra owners using just an SAFC to get the power that they want.

Ok will do.

Ali SC3

iTrader: (10)

I just don't see the point in doing all that to still have high compression.
TT pistons, TT gasket, and still high compression... I would be upset.
192 is basically higher compression than the regular old 2jz-ge.
I don't see how its any safer to run boost on that motor compared to a high compression 2j
Am i missing something here?

Im not trying to knock anyones setup, I was on the edge of my seat when I read your thread Jonboyb, Its a sweet and unique setup but second time around I would try and get that compression down for sure.
**edit** I know what quickgs300 is gonna tell you to do. we had this same talk the other day.

turbodremz

iTrader: (18)

I understand what your saying, just looking at options that have been shown to be good proven setups. If I do decide to go the 1.5j route, I WILL find a way to lower compression. Right now its just an idea Im tossing around, and getting the pros/cons of. But again I do see where your point is, but now have a bit of confusion how I see so many dyno videos of 1.5J mk3 supras running 12-18psi with no issues.

And I already talked to quickGS300, and right now am just waiting to see what route I decide to take, and compression/cam/block options I can come up with to reach my goals for the next step. Nothing is rock solid right now, just tossing it around.

99SC42

iTrader: (44)

Yeah that's why, you will need like 2 or 2.5mm HG to bring it down + some TT pistons.
I am doing the same exact setup on my friend MK4, you just need a good Turbo,272HKS and AEM.
I wouldn't waste my Time on those GTK turbo,with the Billet 67 8.5.1 CR or maybe a little higher, 272 HKS, AEM and good Tune 33psi should be around 740rwhp.
You wanna have room for error in case something happens your engine will safe, and you have time to get off the gas pedal.

Ali SC3

iTrader: (10)

I have been wondering the same thing. must be keeping the boost low or running a thicker headgasket.

you can run anything you want really ... until it detonates

turbodremz

iTrader: (18)

True. The only thing that made me consider the 1.5j is the number of them I have seen that are making good power with minimal effort. I think the 1jz head with a 2.5mm hg should be fine, but I think I will have to actually look over hard data for compression and quench area and try to calculate the best hg thickness to give a safe compression without leaving too much room for error..I think that made sense.

t70 supra

iTrader: (-4)

if u want that soarer setup let me know just sold the splug cover i have everything else