[cpurage]

Hi All,

I have a few question that I want to ask:

I’m about to try to do with my same 2003 IS300 sportcross wagon, but I want to also keep it full interior and street legal, so I have a few questions about my future build and excuse me in advance if it rude from my side to directly write a post in your tread but I have a few questions that I need in advance before I open my bottom end start building it properly with forged stuff so here is the list with my questions:

1. Front oil pan sump vs rear oil pan sump, in terms of drifting when you accelerate and spin the tires theoretically the oil will go in the back, but when you break to weight transition the car it goes again in the front, also the front sump oil pan looks like it have smaller nose and is sucking the oil much faster because of the tighter hole right ? Or I’m wrong about it, that’s why I’m asking you guys as you may know better than me ! So please let me know which one will flow more oil and and there will be no oil hunger while drifting, my build is IS300 stock GE (fully stock GE head with stock cams springs etc.) forged pistons, rods etc. I’ll use Speeduino custom STM32 base 6 cylinder sequential one that I’ve actually created and designed on my own !

2. Do I need to choose specific pistons and rods in order the engine red line to go higher redline or this will be achievable only with higher lift cams such as BC264 or BC272, because mainly I would love to keep stock 86mm cylinder bore (only if the cylinders are in perfect condition of course and if it could stay at 86mm and not necessarily to be re-bored ! If not then it will be re-bored)

3. I’ll be swapping BMW ZF CS6-53DZ 6 speed manual (currently with stock Auto A650 one) with PMCMotors full kit dual or single heavy duty clutch, so my question about that is, how or do I need to delete Traction Control and how ? I mean that currently even TC is switched off it simply is not switched off, I start sliding and it kicks in again, may be because of the Auto Gearbox dunno ? I prefer to keep TC but only if I will be able to completely turn it off and switch it on (when needed), no idea if the manual gearbox IS300s can fully turn it off and drift with TC OFF ?

thanks in advance for your kind help in advance !

 

[_zaclemore]

Rear sump will not work on these cars. There's not enough room behind the subframe since the steering rack. The rear sump is more of a mid sump if you look at images.

Rods and pistons will be fine for high redline, but you probably won't see a difference even with 264° cams. I didn't at least. Technically you can rev higher without them too, I used to rev to 7200 on stock motor.

If you don't care about ABS either, I believe you can pull the ABS fuse to get it to be always off. I would double check on that one.

 

[DriftDaddy]

I'm not super familiar with IS300 specific's. We have a small shop and mostly do drag racing and muscle cars, but here's a couple things that apply to any and all platforms.

Oil control is a big issue to address in any form of racing. You are on the right track with wanting to control oil slosh. As odd as it seems, front vs rear sump doesn't have the effects we would normally think. Plenty of high hp Ford's drag race with a front sump without issue. Plenty of road race style cars use a rear sump without issue. Of course not all front sump pans are created equal, same with rear sump. The big features I would be concerned with are trap doors and baffles in the pan. These in effect create a small isolated sump in the pan that allows oil to drain in, but not drain away from the sump during high G maneuvers in any direction. Check out Milodon's website or YouTube for examples. Whether the IS300 needs any of these I don't know.

Longer pick up tube has no effect on any engine I've ever built. The biggest detail is getting the pan to pickup clearance correct. Usually 3/8".

There are throttle locks available for the IS300 that effectively bypasses the DBW system. It does create a heavier pedal. They are cheap and easy to reverse if it's not what you are after.

I'm not sure what you are using for engine management, but any stand alone or piggy back should only need a TPS signal to operate. You could swap to any number of DBC throttle body and throw the traction control and DBW stuff in the trash.

 

[cpurage]

Thank you for your answers.

Ooh hell yeah I’m gonna put an additional oil cooler somewhere in the front or wherever I find a place for it as this block is not having oil squirters and will be getting very hot with such high revolutions and without the oil squirters… but I don’t need them cause I know with them the whole oil distribution and flow (even in the head) will be lesser and if the block is without oil squirters is better for the head and the rest of the places in the engine where the oil flows !

 

[_zaclemore]

I have the Tomei oil baffle setup for front sump. I think it's a cool thing to have, but I will likely never tell the difference between it and stock.

 

[Hodgdon Extreme]

I'm rather ignorant to drifting in general, so please ignore me if I'm just being dumb...

But aren't drift cars subject to fewer G forces than a track car that's trying to minimize lap time? Usually oil pan baffling is designed to deal with sustained high G's. It doesn't seem like a specialty pan would be required for drifting.

Also, isn't drifting more about skill/control and less about engine performance? I get that you need enough power/torque on tap to create wheelspin basically whenever you want - but is spinning the wheels while bouncing off the rev limiter @ 7500rpm better than spinning the wheels while bouncing off the rev limiter @ 6000rpm?

If I'm being dumb, just tell me so and I'll STFU.

 

[Thatblueis]

An oil cooler and maybe a baffle would be a good upgrade. As for rpm I would upgrade to 272 or a S2 cam or not bother. Both cam need valve spring upgrades. I wouldn't go past 7200 ish with stock pistons for fear of ringland failure especially drifting. You can pull the ABS fuse to fully kill traction control but it will kill all the e assists. There is a post about a mod to fully kill tc and make it switchable.

 

[cpurage]

An oil cooler and maybe a baffle would be a good upgrade. As for rpm I would upgrade to 272 or a S2 cam or not bother. Both cam need valve spring upgrades. I wouldn't go past 7200 ish with stock pistons for fear of ringland failure especially drifting. You can pull the ABS fuse to fully kill traction control but it will kill all the e assists. There is a post about a mod to fully kill tc and make it switchable.

Sorry for my rude and dumb request, but I don't know which one exactly is and I doubt that I will find it with ease, so may I kindly to ask you to point me to the "fully kill tc and make it switchable" post ? I mean I know how to use the search engine here, but you know which one is it exactly so I will truly appreciate your kind input and thanks in advance

 

[cpurage]

I have the Tomei oil baffle setup for front sump. I think it's a cool thing to have, but I will likely never tell the difference between it and stock.

It is a must, here a simple explanation picture for dummies like me:

it is always keeping your motor with full amount of oil because of its strange greatly engineered design

 

[cpurage]

Ok so I will ask probably the most dumbest two questions I’ve ever asked in my life but I’ll ask them:

1. Can I directly open the motor from the bottom without even pulling it out from the car, remove be the whole oil assembly (with the oil pan) remove the con rod bolts, then remove crank, then pistons and rods and the measure the cylinder clearance etc. without even removing the head, and then headgasket will remain the same 0.3-0.4mm stock HG for the GE motor, and if the cylinders are OK, can I drop forged pistons, rods etc. … yes from bottom end directly, I know someone already did it, does it makes any sense to be done this way ?

2. Is the 1.5JZ a much better solution than what I wrote in my question number 1 ? I mean I would prefer to buy 1JZ-GTE head and do 1.5JZ monster and will be much better for drifting because of the better head flow right ?

sorry guys I don’t want to be rude by asking such idiotic questions but this will be my first ever build and thank you for your kind patience and understanding in advance and I assume my question number 1 is rhetorical and dumb one but it is what it is I’m asking it

 

[DriftDaddy]

Ok so I will ask probably the most dumbest two questions I’ve ever asked in my life but I’ll ask them:

1. Can I directly open the motor from the bottom without even pulling it out from the car, remove be the whole oil assembly (with the oil pan) remove the con rod bolts, then remove crank, then pistons and rods and the measure the cylinder clearance etc. without even removing the head, and then headgasket will remain the same 0.3-0.4mm stock HG for the GE motor, and if the cylinders are OK, can I drop forged pistons, rods etc. … yes from bottom end directly, I know someone already did it, does it makes any sense to be done this way ?

2. Is the 1.5JZ a much better solution than what I wrote in my question number 1 ? I mean I would prefer to buy 1JZ-GTE head and do 1.5JZ monster and will be much better for drifting because of the better head flow right ?

sorry guys I don’t want to be rude by asking such idiotic questions but this will be my first ever build and thank you for your kind patience and understanding in advance and I assume my question number 1 is rhetorical and dumb one but it is what it is I’m asking it

1. No. Pistons come out the top. Plus you can't get the crank out as it's bolted to the torque converter or clutch. Head has to come off.

2. I'm not sure.

3. No rude questions. It's how we all learn.

 

[cpurage]

Hmm this is strange, superstock is saying that the quench area should be no more than 0.060” (1.524mm) but a friend of mine who is building boxer engines just told me that the quench shouldn’t be more than 1.0mm so I’ve recalculate my eventual build and I do get the following compression ratio, which to my friend which is building boosted boxer engines is saying that it is too low and should be at least 9.0:1 or over 9.0:1 :

So I assume I’ll need thinner head gasket in order to make it exactly 9.0:1 , right ?

 

[Hodgdon Extreme]

Most engine builders would agree you want the piston to get as close to the head as possible without actually touching - accounting for rod and crank stretch, piston rocking in the bore, etc. Rod/crank stretch will depend on piston/rod weight, strength and rpm. Usually it ends up working out to somewhere between 0.030" and 0.040" Piston to head clearance. It's noteworthy this is contested logic. Some RB26 tuners swear by wildly increasing piston/head clearance. I subscribe to the theory of as little clearance as possible. It's also worth mentioning this is much more important for larger bore OHV engines with "wedge" style heads - they have a huge quench pad vs the 4 tiny patches typical of most 4V heads.

Toyota kinda dicked us over with their GE design comprising a super thin head gasket and counterbored deck surface of the head. As delivered from Toyota, there is good/proper piston/head clearance - but the HG is too thin for turbocharged reliability. Thickening the gasket for reliability means increasing the piston/head clearance. You could mill the deck surface of the head down, but that will change your cam timing and weaken the head. Kinda a bummer.

Compression ratio depends on what fuel you'll be using and how much margin for tuning error you desire. I'd say 9.0:1 for gasoline and 10:1 for E85 is about right.

 

[theraflu]

The 2JZGE comes with a good OEM oil pan baffle. Oil starvation and as a matter of fact fuel starvation is not a factor in most street friendly builds. That’s my personal experience and everything I hear from other guys. That said I’m not a drifter.
Oil cooler is a must tho, high RPMs and probably low airflow from drifting (correct me if I’m wrong) will cook the oil.

 

[Hodgdon Extreme]

1. Can I directly open the motor from the bottom without even pulling it out from the car, remove be the whole oil assembly (with the oil pan) remove the con rod bolts, then remove crank, then pistons and rods and the measure the cylinder clearance etc. without even removing the head, and then headgasket will remain the same 0.3-0.4mm stock HG for the GE motor, and if the cylinders are OK, can I drop forged pistons, rods etc. … yes from bottom end directly, I know someone already did it, does it makes any sense to be done this way ?

2. Is the 1.5JZ a much better solution than what I wrote in my question number 1 ? I mean I would prefer to buy 1JZ-GTE head and do 1.5JZ monster and will be much better for drifting because of the better head flow right ?

You can drop the front crossmember and then do the pan from below. You'll obviously need to devise some means of supporting the engine. Be careful. I did this to correct an oil leak. Don't know if it's possible to replace the rods/pistons from below; but it seems like going around your ass to get to your elbow.

From the data I've seen, it's a myth the 1J head outperforms the 2J head. To me, the 1.5J only makes sense if you started with a 1J and either hurt the bottom end or want 500cc more displacement. If you start with a 1J, all your plumbing and wiring is based around the 1J top end - in that case it makes sense to simply replace the shortblock underneath.

 

[Thatblueis]

The 1.5jz is not worth it. It was made if you had a 1jz head and blew the bottom end as 1jz engines are rare but 2jz bottoms ends were plentiful or you wanted .5L more disppacent and didn't want to build a new head. You can get the pan and windage tray off with the engine in the car but rods and pistons require pulling the head, even if you could it would much easier to pull the head. 9:1 will be a safe pump gas with good overhead for boost. If you go e85 depending on your e85 quality, anywhere from e45 to e85 you could run 11:1. After that it's really dismissing returns.

 

[cpurage]

Most engine builders would agree you want the piston to get as close to the head as possible without actually touching - accounting for rod and crank stretch, piston rocking in the bore, etc. Rod/crank stretch will depend on piston/rod weight, strength and rpm. Usually it ends up working out to somewhere between 0.030" and 0.040" Piston to head clearance. It's noteworthy this is contested logic. Some RB26 tuners swear by wildly increasing piston/head clearance. I subscribe to the theory of as little clearance as possible. It's also worth mentioning this is much more important for larger bore OHV engines with "wedge" style heads - they have a huge quench pad vs the 4 tiny patches typical of most 4V heads.

Toyota kinda dicked us over with their GE design comprising a super thin head gasket and counterbored deck surface of the head. As delivered from Toyota, there is good/proper piston/head clearance - but the HG is too thin for turbocharged reliability. Thickening the gasket for reliability means increasing the piston/head clearance. You could mill the deck surface of the head down, but that will change your cam timing and weaken the head. Kinda a bummer.

Compression ratio depends on what fuel you'll be using and how much margin for tuning error you desire. I'd say 9.0:1 for gasoline and 10:1 for E85 is about right.

Ok this makes the whole picture now, so I’ll be rubbing 100 Octane (here in Easter Europe it is also called 98, so this is equal to 93 in the US I think so). And I just found my best HG thickness and here it is with the 86mm STD Manley 9.0:1 dished 10cc pistons:

And another question which is important for me is what would you run in terms of intake manifold + throttle body setup, so this:

Or this:

 

[Hodgdon Extreme]

what would you run in terms of intake manifold + throttle body setup

Here's what I would run, since you asked:

That's a GTE upper plenum, a Taarks throttle body adaptor to marry a Bosch DBW throttle to the GTE upper, and Dodo Racing GE-T lower runners to marry the GE head to the GTE upper.

My thoughts on the two options you posted:
The fabricated manifold has significantly shorter runners than stock (both GE and GTE), which will tradeoff a significant amount of low rpm torque in exchange for a handful more torque at high rpm...as in 7000+ from the data I've seen. To me, this is a poor tradeoff. The fabricated manifold also places the throttle in a spot that tends to interfere with the ECU box. This may or may not be an issue for your application.

The adaptor you posted that marries the GE lower runners to the GTE plenum introduces a bit of a kink into the intake runners, which isn't ideal for performance. It also moves the GTE plenum quite a bit further outboard in the car as well as a lot higher. At the very least, you'll need to do some grinding/clearancing on one of the hood braces...this is just to get the plenum itself to fit under the hood. Getting a throttle to fit is another story.

I bought one of the adaptors and got it all worked out, prior to buying the Dodo Racing GE-T lower runners. If you check out posts 17, 39 and 45 in the thread below, you can see some pictures of the hood clearacing I had to do, and how I arranged my throttle. I'm not going to use these parts if you'd like to buy them.

GE-VVTi NA-T Makeover

EDIT: This thread began with me asking what throttle body options are out there for a FFIM conversion using the GTE upper manifold but it morphed into me covering the particulars of the GTE FFIM conversion and overall update of the powertrain. EDIT 2: After beginning the project, a new product...

www.my.is

 

[cpurage]

Thank you Hodgdon Extreme, I’ll think about it and will let you know (shipping to Bulgaria will be very expensive, but anyways)… I’m now in front of another dilemma, I just realized that the stock TT pistons+pins+rods are much heavier than the Manley setup that I want to use Manley 9:1 STD + Manley Pro Series Turbo Tuff I beam

and my question is (is it mandatory) do I need to lightweight and grind the stock crank or if I stay with stock crank and even with less weight of the Manley pistons + rods, it’s ok the crank to stay at stock weight as well? Please let me know once !

 

[Hodgdon Extreme]

Lighter rotating/reciprocating components are always better - that is, until they're not strong enough to handle the loads/forces.

Choosing the lightest components strong enough to handle your intended abuse should be done by someone highly experienced in building/abusing 2Js specifically (that's not me).

You'll need to have an automotive machine shop balance your crank, rods, pistons, pins and rings as an assembly - regardless of which components you choose to use.