Looking into an eventual motor refresher for my ISF. I'm wondering if anyone has any first hand knowledge if the 2UR-GSE from the RC-F and GS-F is backwards compatible. I know they share the same architecture but how about ECU, sensor output, plug type and transmission compatibility. Does anyone know definitively? Please refrain for speculation, I can do that myself. Currently trying to arrange a side by side comparison.

Thanks

 

The fuel systems are significantly different under the hood. The later model engine has three lines coming from the back where the early version has four. Not sure about the wiring, I haven't looked into it, but it would only make sense to do the transplant with the OEM wiring harness and ECM/TCU appropriate for the version. Integrating that might present some challenges from a wiring perspective. You'll also have to decide what to do with the air/oil cooler circuit - run it, bypass it, downgrade it to the earlier version.

I've been looking at this for a similar reason, and because the IS F would really benefit from the later engine because it's so much lighter than the RC F and GS F. Even the RC F Track Edition is heavier than the stock IS F.

 

If either of you do this, please fully document it for us. With the cost of building these engines, I’d rather upgrade to the newer version if I ever hurt my current engine. The upgraded fuel pressure and valve train components would be nice to have.

 

It would be a nice upgrade to the IS F. My concerns are similar to Lobux’s. To get the real advantages you need to use the RC/GS/LC engine ECU and it is basically one generation newer as far as electronics go. The Engine ECU communicates with the rest of the vehicle in a lot of ways, and most are probably similar. The biggest issue will likely be VDIM/ABS. You’d need to try I suppose, but I suspect the ABS ECU will be upset with the newer engine ECU.

Best bet in my mind would probably be to try to retrofit the newer ABS system along with the engine.

As far as the fuel lines go, you would need to ditch the return line from the high pressure side. 77024-53030 is the fuel pump hanger that would fit the IS F without the return line port. Other than that the lines are similarly located in both cars so I don’t think you’d need to do any further modifications.

Jeff

 

The direction I was thinking was getting a wrecked RC F or GS F and transplanting as much as is practical to prevent ECUs from having hissy fits over not hearing from an anticipated source. Could likely leave the infotainment alone, but pretty much everything else is going to need to find a new home in the old platform - TCU, VDIM, Certification ECU, Power Distribution, etc, etc,. That's what makes this a daunting task for sure. I strongly doubt the later model engine would work with earlier engine management, and the later ECM/TCU will be looking for inputs from a host of other computers not necessarily present in the early model platform.

For a stripped out track car, this would seem to be an easier proposition, but the devil is in the details for sure.

 

I’ve not experimented myself but I suspect the power control and immobilizer would maybe communicate properly with the engine ECU. Hard to know without trying it, having the engineering details, or being an engineer who worked on the components haha.

Would be fun for sure, though if I was just building a stripped out track car I would possibly consider other options.

Jeff

 

I just perused the system diagrams of both the IS F and GS F. They are very similar, but have some substantial differences, and those include multiple CAN connections on the newer ECM. That could be truly confounding.

 

How about this:

https://www.clublexus.com/forums/is-...-is-500-a.html

RCF engine into a current generation IS.

Lou

 

Exactly the way I was thinking you'd have to do it. Buy a wrecked car, and transplant everything you absolutely have to have. Probably a little easier since they're the same generation, but looking at the spaghetti wiring in one of the photos reminds me of RB36 DETT swaps into 240SXs. Lots of wires getting transplanted to the right connector bodies in the right places. That's the tedious part for sure.

 

I've also looked into this option since I've had my motor rebuilt before and I only know of two other people that can say that. The fuel pressure for the RCF and GSF platforms are a lot higher around 3000psi and the fuel pressure for the ISF is around 1800psi so they are not compatible, It could work if you were to rewired the ENTIRE car including the instrument cluster.

 

It sure would be nice to see a HPFP upgrade for our cars. Then building the engine would be the superior option. There are HPFP upgrades for many other vehicles, so disappointing that we don’t have that option.

 

I can't find hard evidence there is any difference in the high pressure injection pressure. Guess which procedure is from the RC F and which is from the IS F:

 

Modified for truth. Our cars are not found in any serious competition. If they were, we'd have all kinds of options from a range of tuners. Toyota/Lexus just don't make cars people want to race in competitive series.

 

^^^^

https://www.motor1.com/news/137471/l...-f-gt3-geneva/

Lou

 

The Ford F-150 had HPFP options prior to the release of the Ford GT. Maybe that’s atypical?