JBurke034

I need your guy's help. I'm getting further into my build and after researching this car (2010 IS250 RWD) I see tuning with the stock ECU will be a no go. Does anyone know of someone using a stand alone on the 4gr. I'm not a Toyota guy but building this engine with 8:1 compression for twin turbos to hold 25lbs of boost won't be a problem. I just want to make sure I can tune it when I'm done. Also does anyone know of a way to upgrade the stock fuel system. And please refrain from the just trade it for a 350 or drop a 2jz in. I want to use this engine. It's and IS250 so I want to keep it an IS250. If horse power was the only concern I'd just stuff a boosted LS6 engine in there and call it a day. I try ed to search your boards and find info but I could not. Any help will be greatly appreciated.

Gville350

iTrader: (10)

I don't believe we do unfortunately. But there are places that now advertise being able to tune the 2IS ECUs.

Though it mentions the IS350, they've already tuned a member's IS250.

http://www.rr-racing.com/RR-Racing-L...is350tne01.htm

The closest someone has gotten to a standalone is a member having used the HKS F-con unit,

JBurke034

Thanks for the info I'm going to give these guys a call tomorrow. One of my closest friends grew up in the town this company is in and I go right past it on my way back home to Jersey when I visit. They are only showing a listing for the 350 but that might workout better for me anyway because I want to run dual port injection. I'm not a big fan of scrapping this ecu and losing other functions and features on my car.

Gville350

iTrader: (10)

RR Racing has been the most accommodating vendor on the boards here and I've personally purchased their USRS components. Worth taking a look at; might help with front tire life on your wild build here.

So you're eliminating direct injection altogether?

Any leads on those custom pistons?

Unless you have a better solution for the source for the turbo feed lines, you can use the low-pressure access port right next to the oil filter canister in the front of the car as a feed line. Then simply tap the pan for the drain.

JBurke034

Getting the pistons and rods won't be a problem. JE can make me any piston I want and getting high strength rods won't be a problem either. I'm waiting to get more info about tuning and what ever configuration the tuner I choose recommends that's what I will build. A part of me wants to leave the stock internals because from what I read they are pretty strong. 12:1 compression reliably can't be done with weak parts. The heat is my only concern and the stock pistons look like they can take it.

I raced and built crotch rockets for many years. The same method we would space the heads for a stroker kit on a Hayabusa should work to lower the compression on this engine. A 3.2mm (+/- head gaskets) plate will get me at 8:1. I want to try this because if it works it will be an easy option for anyone wanting to do FI. Using the port injection would be my goal (my 400hp Mazdaspeed 3 uses it well) with adding port injectors for the extra fuel I'll need if I can get it out of the port injectors. As far as I can tell from the head gaskets the 2gr & 4gr heads will swap. If I can do what I think because I haven't physically put them side by side just the head gaskets. I can Deck the 2gr heads make my plate 4mm (for strength & valve clearance) then use the lower intake (where the port injectors are housed) off the 2gr as well.

I'll probably solve the oil problem with a wet sump. I have access to cnc mills and lathes. Meaning my life time good friend owns a machine shop and I just walk in and make whatever I want. All you Lexus IS250/350 owners wanting to do reliable FI is making want to try some stuff and see what happens. So if it does I can spread the word and hopefully help some people out.

Gville350

iTrader: (10)

Though the factory IS250 pistons are hypereutectic, I'm not sure if they'll be up to the task of taking on high compression and twins. Add the fact that the piston tops won't benefit you at all with their funky DI design. I'd definitely go the forged route. Perhaps E85 would cool it enough be stable though.

Any thought to just getting larger injectors to forgo the dual setup? That spacer really interests me and confirming that the two model's head will swap would be good to know.

The sump is a good idea and has actually been done before :

http://www.turbofast.com.au/GT86.html

I also need to mention that this Aussie did use a Vipec i88 standalone with twins on a 2GR-FSE motor in a better chassis! 1000cc port injecters only was also used.

DickH

I would get the desired compression from a different piston instead of messing with the head gasket and whatever spacer. Y might run into alignment issues with the front cover and the intake ports will be offset.