aventur2

Also curious to see 1/4 mile times and 0-60

Jeff Lange

iTrader: (1)

I'm not at Country Hills, no. I was/am at Stampede Toyota, however I recently started an engineering degree and so am not there very often any more. Still, perhaps we should have some sort of Calgary Lexus meet at some point. I won't be driving the car in the winter, but maybe we can make something work.

It was just before/at the same time that the tuning was just starting. I even spoke with RR Racing and TTFS during my swap regarding possible options. RR was interested but TTFS was not. I spoke with RR about various approaches to the issue. They did seem to think that retuning the IS250 ECU was a good option, and it would be nice because it would already be set up for a manual transmission, however the main issue is that the 4GR has D-4 and the 2GR has D-4S. The IS250 ECU only has injector drivers for 6 injectors and the IS350 engine has 12. There are also other issues such as the fact that the 4GR has ACIS and the 2GR doesn't. The IS250 ECU has a sensor to verify that the ACIS actuator is working properly. Without this installed, the 4GR ECU would throw a code. So basically, you would need to delete the port injectors (or just not run them), and then figure out how to install the ACIS/intake manifold from the 4GR onto the 2GR or build something to lie to the ECU, or reprogram the ECU to ignore that input.

My point is, I considered at least 4 potential solutions to the problem and went with the one that seemed most likely to succeed. It did end up having some challenges as well, but it was what I thought had the best chance of working as intended.

I'm not entirely sold on the idea that swapping a manual transmission into an IS350 would be cheaper than swapping an IS350 engine into a manual car. You would need a lot more custom parts, and a lot of other pieces would be expensive or hard to find (interior pieces, pedals, etc.). As for why I kept the stock IS250 transmission, I never had a worry about the RA62 transmission holding the torque of the 2GR, I've said for years that it was more than capable. It was others that seemed to think it was a weak transmission even though it was used in heavier cars with higher output engines than the 2GR. (In fact Toyota even used it behind a tuned version of the 2GR in the GRMN Mark X).

Doing the swap on my car was a lot of buying this and assembling that, the only real modifications came with regards to electronics. A V160 swap would require a custom bellhousing or adapter, custom flywheel/clutch setup, a custom drive shaft, custom mounting, some shifter modifications, possibly transmission tunnel modifications, at the least. I actually have a Jack's Transmission Stage 3 V160 sitting in my buddy's basement, but it was never even considered for this project. There's no need. In fact, that transmission is destined for a JZA70 Twin Turbo R, which will actually require many of the same modifications, but in that case it is worth doing.

Currently my only project with the car is looking into potential clutch upgrades. I am working on a custom flywheel setup that will allow the use of a larger sprung disc and a different type of pressure plate. I am considering a few options to get rid of the dual-mass flywheel, but am not interested in the aluminum flywheels made by Fidanza or SPEC.

Jeff

Jeff Lange

iTrader: (1)

So I've driven the car about 20,000 km over the last year and in that time I have decided that while the clutch setup isn't terrible, it could use improving. The throttle response from the 2GR-FSE is better than the 4GR was and as such having the dual mass flywheel with the dampened clutch disc, while smooth, can actually be a bit annoying in certain situations.



After spending some time thinking about options and designing a new flywheel, I found what I've put together what I was looking for. My new flywheel is chromoly steel and weighs about 2/3 of what the factory dual-mass flywheel weighs. While it is lighter, it still has some weight to it.




I am using an Aisin NVR 250mm clutch disc with a larger inner and outer diameter and a much larger sprung hub. I've used the NVR clutch discs in a few of my other cars and always been very happy with the way they drive. I will be keeping my existing pressure plate for now, but with the larger clutch disc, it should hold about 20-25 ft-lbs more torque while maintaining the same pedal effort.



I hope to get it installed shortly, depending on how the weather looks. I've still got the Potenza RE-71R's on the car and they don't care much for the snow, haha.

Jeff

Gamer80

Been following this thread for a bit now, and I'm super excited to see all that's been done!

That being said, I have a quick couple of questions for you, Jeff:

Is your new flywheel an off the shelf one, or a custom design of your own?

Also, to whom did you send the IS350 ECU, in order to delete the ATM? Were there any other options to trick the ECU into thinking the ATM isn't there?

Jeff Lange

iTrader: (1)

It's an off the shelf unit, though I've never seen anyone run one before. The design is very similar to the one I had been designing (mine was a bit lighter and used a different pressure plate). It saved me a bunch of hassle to have one that already existed, haha. It's a little bit of a compromise on what I wanted, but it's way quicker and easier, and is really what I wanted in the first place.

I looked into a few options, and if you read through the thread I talk a bit about the ECU, but in general I don't think there are any good ways to get it working without having some sort of reprogramming done. I did manage to drive the car a bit with an unprogrammed ECU, but it randomly stopped working shortly afterward, and I of course had no TRAC/VSC and the CEL/TRAC lights were on.

Jeff

kickin8

iTrader: (1)

Would the F-Sport pressure plate work? They claimed to have 30% more ?

Jeff Lange

iTrader: (1)

The F-Sport has approximately 15% more clamping load than stock, which increases torque capacity to approximately 290 ft-lb. The pressure plate I am using is just a tad stronger than that, at approximately 17% more clamping load than stock, good for approximately 300 ft-lb. With the new clutch disc, I will have approximately 25% higher torque capacity from stock.

Stock pressure plate has a 6860N clamping force with a 236mm clutch disc.

Jeff

SebaPR

im still interested in trying this now more than before since tuning the is350 ecu is readily available. Has anyone tried the pre 2008 gs350 engine in a pre 2008 is250 m/t (non vdim with non vdim)???? Can the errors be fixed with this stock ecu reflash tunes they offer at local dynos? I would really like to try the non vdim swap i can live without abs/tcs/vsc/cel as long as it runs like a is350 with a manual trans electrical tape solves the lights lol

liqB

Jeff, have you put in your new FW? how does it feel?

Jeff Lange

iTrader: (1)

It's been a bit of a crazy year, meant to post some updates earlier, but didn't get a chance to.

I did get the flywheel installed along with the new clutch disc. It feels fantastic, though I may still adjust it a bit, not sure yet. Much lighter makes for a more rev-happy experience, but it's not crazy light and so does still drive very smooth, as a Lexus should. Additionally I did replace the 3.91:1 Torsen T2 differential setup with a low mileage 4.10:1 T2 to give me a bit more gearing advantage and did a few other items here and there as well.

Original Dual-Mass Flywheel (120,000 km, 20k of which was with the 2GR-FSE), still in spec, but heavy:


New Aisin NVR clutch disc beside previous TSB-updated clutch disc. More torque capacity:


GRMN clutch line/hose setup with no accumulator to replace my previous pieced-together setup:



4.10:1 Torsen T2 Limited Slip Differential:


In an effort to freshen-up but also increase a bit of the tight feeling of the car, I went ahead and replaced a few of the bushings/mounts on the car. I carefully considered which engine mounts to go with and almost went with the Megan ones, but I just couldn't get enough confirmation about their characteristics to make the leap.

2GR/6MT engine mounts / GRMN transmission mount (stiffer than 4GR):


Replacement shifter bushings:


TRD differential mounts/stoppers (front upper/lower and rear solid rubber instead of liquid-filled):



IS-F rear subframe mounts (stiffer than ISx50 stuff):


Overall, the car feels fantastic at this point, I am still considering other ways to improve its performance, however now that I am back in school things will likely progress a bit slower.

Jeff

Individual

iTrader: (7)

Awesome updates Jeff! Thank you very much for sharing your wealth of information.

The great thing is that you got the most important stuff done before school starts

Gville350

iTrader: (10)

Thanks for the update Jeff! Keep the beast alive and running well!

jgarrido

iTrader: (1)

Jeff whitout accumulator the biting point clutch is too high,is normal?

Jeff Lange

iTrader: (1)

Yeah, I reckon so... still, I'm always thinking of other ideas, many of which cost money, haha.

Working on it. I wouldn't mind it if winter could be over though. That would be nice.

To be honest I didn't really notice a huge difference in the engagement point after removing the accumulator. I noticed a bigger difference when I changed out the flywheel, and it is a bit higher than it was, but I wouldn't say it's too high.

Jeff

AFlex

Jeff

Great to see the 6MT beast is continually getting upgraded

I think you asked previously on a separate thread whether anyone had experience of the Megan mounts and I mentioned I had purchased some but not had the chance to install yet... Months later, they are still in the box waiting to be installed!

How difficult is the engine mount install procedure? Did you go about it by raising the engine up with a hoist? (i am too afraid to lift the engine upwards by jacking on the oil pan)

Or did you lower the subframe? I'm trying to work out what is the best approach.

My local Lexus d(st)ealership tried to make out it was a very time consuming job and quoted 4 hours labour - but most of the DIYs i have seen for other cars make it look like more of a 1hr job.

Were there any complications in replacing the engine mounts that made it a longer job?

Thanks!