iTowils

I have everything for a w58 swap in my 97 sc300, except for the ecu. I found one of the rare 97 m/t CA spec ecu's on ebay, but it's listed for $850. I'm not sure if it's worth throwing down the money for that, or how much I should be paying for an ecu, or if I should just pass on the ecu and just bypass the NSS.

Any suggestions and opinions are much appreciated. I also have no experience swapping transmissions, so tips and tricks would be great too. Thanks!

gerrb

iTrader: (34)

The 97 original 5 speed ECU are very rare that is why they are commanding a good price. It is next to impossible even finding them not unless one of those 1 of 120 cars is totaled and parted out .

Is it worth it ? That all depends on how much really you want to convert your car closer to a 1997 5 speed. Is it necessary to get your car running ? No , you can use your auto ecu to get the car running but wont function as exactly the same since the ecu is looking for inputs from the auto trans functionality .

I would suggest try to do some more search on this forum with regards manual swaps , there will be tons of them . Just not sure exactly what info you are looking for but surely you will find a lot here .

iTowils

scsexy

iTrader: (1)

At that price you can almost buy a standalone ECU.... The Question really is how fast are you trying to make your Sc300.

Like Gerrb said you can drive around on your stock auto ecu if your just trying to make sure everything works together and have no further power goals.

You could spend 800 dollars for an ECU that you cant make any faster but will work like its suppose to for your car. Should plug and play.

If you have any kind of power goals in mind then you can go after market Ecu and save yourself the money later when you want to replace that 800 dollar one. also Plug and play but may need to have someone tune the Ecu for your car. You can always tune an aftermarket ecu again whenever you upgrade something to actually benefit from it, Intake, Exhaust, Turbo =)

Its up to you and your plans for the car

iTowils

Thanks for your input!

I'm not looking for more power right now, but it's definitely something I want in the future. From what you've both said, I'll most likely just run my auto ecu and put that $800 elsewhere into my car for now.

KahnBB6

iTrader: (5)

^^ The advice everyone has given is all correct but there is one annoying thing that you will have to factor in: Since you are in CA doing this swap to your 1997 SC300 CA-Spec chassis you are going to need that rare 1997 5-speed CA-Spec ECU due to CA smog testing.

More than likely you will have a CEL without the automatic transmission in the car. The manual version of the ECU is designed to take into account the driver being in full control of the shifting and therefore it works with the emissions equipment (mostly the EGR VSV) differently to account for this. Now it may not be much of a variation but it might be just enough of a difference to make or break your smog test.

And as Gerry mentioned the car won't act perfectly with the auto ECU not being able to control an automatic transmission. It will RUN fine but when shifting the engine control will be a little off... which could affect your emission dyno results at the 15mph interval and the 25mph interval. Additionally if you have a CEL on in the gauge cluster then you would automatically be failed. You can't just remove the CEL light since the tech will verify that the light comes up during startup.

You might be able to remove the auto trans shift solenoids from the A340, plug them into the harness and tie them up somewhere in the undercarriage so that the ECU gets the signals it wants (this is a trick that 1998-2000 SC300 VVT-i owners going with a manual swap have used JUST to make the CEL for the auto trans shift solenoids go away) but you'd still have the issue of not running 100% perfect between shifts... which again is going to affect your smog dyno numbers negatively.

The $850 price is quite high but Gerry is right. They are incredibly rare and that's why they cost so much. In your case in Cali you can't pass smog without one of these 97 SC 5-speed CA-Spec ECUs (or one from a 97 Supra NA 5-speed CA-Spec).

For what it's worth if it makes you feel less alone in such a dilemma I once had to buy an also-rare-but-not-quite-as-rare-as-a-1997-manual-CA-Spec-ECU 92-94 SC300 5-speed CA-Spec ECU from Lexus for $1k after Fedex mysteriously lost my original one in the mail after I'd had it sent out for capacitor repair servicing. I had to have it to pass smog, none were up for sale used at the time and Lexus still had one in stock so...

If you've come this far already I know it's a lot of money but I'd just buy it and move on with your project to carry it through. Not many people do this with 97 SC's in CA so I would say it is worth it just to not have headaches in the future.

At the end of the day you now get to enjoy your SC being manual and so long as your car's emissions are in good shape, CA tests your SC every two years and leaves you alone

For more power down the road you won't be using that ECU unfortunately. There is an upgrade path I'd suggest to turbocharging your manual SC in CA but... well... you'd want to look at my build thread or vigman's build thread for that.

(my SC turbo in CA thread is here: https://www.clublexus.com/forums/bui...-easy-way.html)

(vigman's thread is here: https://www.clublexus.com/forums/bui...-year-2-a.html)