Chris88

Intro.

I have bought a 1995 JZZ31, 3.0L JDM Toyota Soarer as a project car and it's now sitting in storage in the UK waiting for me to figure out what I am going to do to it.
It's in pretty good stock condition and is already the right colour (see below) so I will be concentrating on the mechanical stuff.




I have decided to go NA-T as the main mechanical upgrade (I will be doing brakes / suspension etc. and I think that I understand pretty much how they are done) but although I have owned high performance turbocharged cars (I also have a 93, JZZ30 Twin Turbo and a 96, JZZ30 VVTI Single Turbo right now) I am only just learning about performance car tuning.

I have looked over the forum and found lots of useful information but my problem is that as a beginner much of it is going right over my head, hence this thread which is intended to satisfy my need to know not only the 'how' but also the 'why' before I start on anything.

Please bear with me if the answers to some of my questions seem obvious (remember that the answer is always obvious if you aleady know it).

Chris88

My plan is to produce a car that is suitable for street use and for trackdays and also to compete the conversion in two stages so that I can drive the car in between, learning the good and bad part of what's been done.

Stage 1 will include a large enough turbo (800HP) with all the anciliaries (Intercooler, ECU etc.) to facilitate stage 2 but will be at a low boost pressure. For stage 1 the plan is to keep comparatively a high compression ratio to make up for the turbo lag that an 800HP capable turbo will generate.

This is the turbo that I am currently considering.



As I understand it the Compression Ratio (CR) of the 2JZ-GE is 10:1 and this is too high for a turbocharged engine if the boost pressure is turned up high. In stage 1 I will be keeping the stock pistons / rods and any reduction in compression ratio will be achieved by a thicker head gasket. So the question is;

Running on premium pump gas (97 RON in the UK) what level of boost is safe to run on 10:1 CR and how does the relationship between max safe boost and CR actually look? In other words will I get a better balance of low down performance and overall power capability by reducing the CR just a bit (say 9:1)?

lexforlife

iTrader: (7)

10:0 compression in todays time is really not considered unusually high given the availability of standalone ems units out there and very compentent tuners .

in fact some of the most powerful and fastest supras of today are at same or just a tad under that 10:0 mark..Its all abou proper timing and fueling, and the only way to accomplish that is by full standalone control and a VERY knowledgable tuner . the tuner will know how much timing to run , where to pull and ramp back in. if you are talking about 600 and up rwhp , you are in race gas (high octane) territory anyways which loves timing .

i run around 9:5:1 compression and love the response . at 600 rwhp on 93 oct i have had zero problems since 10/2010

we use 93 oct as prem here and we are able to go as high as 23-24 psi ,so for you at 97 oct i wou;d say a easy 25-27 psi with a solid ems and tuner

Chris88

Thanks for the response but I think that UK 97 RON is about the same as US 93 oct (Isn't US pump oct rating the average of RON and MON?). I will probably follow your lead and drop the CR just a bit using a slightly thicker head gasket, maybe 0.762mm instead of 0.228mm which should drop to around 9.5).
If I do this it should give me a bit of safety margin and as I am going in two stages I will also get to find out how good the tuner really is.

Chris88

I understand that the main difference between the GE and GTE blocks is the oil squirter included only in the GTE block for cooling the underside of the pistons.
Most of the posts I have managed to find on this subject (both here and on other forums) say that this is a big problem when doing a 2JZ NA-T or 1.5JZ conversion and some (on another forum) go as far as saying that you can't use the GE block on a turbo conversion just because it's so difficult / impossible to add the oil squirters.

My question is. Is it safe to use the GE block without adding squirters (ultimately I hope for 600+ rwhp) and if the squirters are essential has anyone added them to the GE, or do they just buy a GTE block?

Chris88

My plan is to use two SMIC instead of a single FMIC on my NA-T conversion. Main reason for this is to avoid fitment of big scoop type front spoiler. I don't really like the look and the roads in the UK are full of speed bumps.
This means that my cooled discharge from the second SMIC will be right across at the LHS of the car and I don't want to go back across to use the existing surge tank, Y piece and throttle body location.
I know that I can have a custom surge tank made with a front mounted TB to fit onto my existing intake manifold but this will probably be hard to design to get the correct intake flow to each cylinder.

My question is; will the standard 2JZ-GTE intake manifold and surge tank taken from a MK4 Supra fit directly onto the inlet side of the 2JZ-GE head?

98$c300

This thread started out with some good 411,for the NA-T noobies.why did the thread die so soon?

frankdms

iTrader: (1)

Intake manifolds do not bolt up the same. 2jzgte or VVTI-gte is not the same as the 2jzge or VVTi-ge.

It would be easy and cost comparative to swap in a GTE...

You already have the swap in the car so- why not. There is a member here and on Supraforums who has gone 6-700 on GE blocks with good luck.With *good tuning and setup to match you can achieve your goals. The Borg Warner you are showing is a good unit. You can get that same turbocharger with a 90* deg comp outlet*. We run the BW s300sx3 with the 90* deg comp housing. We run the smallest one at higher boost levels and have great luck.

Ali SC3

iTrader: (10)

This stuff has been covered many many times on this forum, which is why the response is low.
please do a search on these topics and post your questions in the existing threads.
we have been modding 2jzge's for a long time now, there is even a faq somewhere that addresses alot of this stuff.
also take a read through the great 1jz 2jz nat debate thread, lots of info in there.
https://www.clublexus.com/forums/per...te-thread.html

no you cannot use gte intakes, there are so many threads on this topic you should really do a search.
there are aftermarket options or you can DIY.
why run a SMIC? do you just like hotter intake temps? if you are running 8 psi or less maybe, but a front mount is what will be the best, especially when keeping the stock intake manifold which gets really hot, a FMIC is almost a requirement.

there are lots of discussions on oil squirters, and most na-t will agree that you really don't want/need them above stock boost levels. with the increased pistons temps they start to stress the pistons instead of just cooling them due to suddenly trying to cool them from too high of a temperature where they need to cool down more slowly. while this works at BPU temperatures just fine, when you start pushing the boost and heating up the pistons more, the sudden cooling becomes counter productive.
2jzgte and 2jzge pistons are so good they can handle the heat just fine without any oil squirters.

there are 800+hp 2jzge's with no oil squirters doing just fine. your major limitation will be your gas and your compression ratio.

Chris88

Sorry if I have been going over things that have already been addressed but it's not simply a matter of being lazy. I seem to have a major problem with connection speed (I am normally in Southern China) and every search page etc. seems to take forever to load with many wasted efforts due to loss of connection.

Ali SC3

iTrader: (10)

I figured there was something to it which is why I didn't close the thread, if you have specific questions post them up.
There are lots of experienced na-t members on this forum that are willing to help.

generally the na-t process is pretty straight forward if you have installed a turbo before.
the electronics can get a bit tricky with the stock ecu, but since the TT ecu mod, there is an easy route to getting an na-t running properly that upgrades all the ignition as well. Since you have a JDM car you already have a map sensor setup, but your ge ecu won't let you boost past a few psi before tripping the cel.
good news is its even easier for you to switch to a TT ecu than the rest, you already have the map and IAT.
likewise you can also go to a standalone that much easier for the same reasoning. good luck.

marshall2j

Quick question. PT61 w/ Greddy HG NA-T, with B&M ignition amp, running AEM V1

Low boost AFRs (like 7psi)- what are you guys running
Spark plug? Currently using BKR7E with existing gap, like .032

When I'm flooring the car, I'm getting weird ignition breakup like seat of the pants feeling... like I floor it, around 3500 sometimes the car would hesitate for a "barely noticeable" instant then do it again around 5K plus. Can barely notice it, I don't think it's a knock event, but will confirm today. Timing is very conservative~ mid to upper teens. Will plug in computer tonight to see, but was wondering what people's opinions are regarding above info

Ali SC3

iTrader: (10)

stock distributor at you want to be .028 or lower generally. you will normally get break up at .032, but since you have an ignition amplifier it should be better than what I am used to as mine was stock at the time and I was running 9 psi then 12 psi and I had to go down from .026 to .024 with the aem and no ignition amplifier to not get any brake up in boost. I was loosing a bunch of power from the low gap but it "worked".
also make sure your AFR's are not overly rich or that will also cause brakeup if you don't have the extra spark energy to handle the excess fuel.
coil dwell settings can also have an affect but with 1 coil running 6 cylinders you are very limited in charge time.