Thinking about aftermarket ECU for my Toyota...

[Spinnetti]

Anybody know if its worth it on the 4age? wisdom used to be there was not much to be had in this motor (unlike the hondas)....

I'm also looking for someone within reasonable drive distance from Cincinnati who could do a baseline dyno, then tune the new box and redyno...

Thnx.

[Chip42]

problem with the 4age has and will always be the cams. the ecu will help with response and yield some hp, but no - it simply isn't a honda...

[quadzjr]

There is a good write on this on the http://www.mr2oc.com webiste. There are alot of people that installed stand alone systems like a megasquirt, and saw minimal gains.

[raceita]

I'm considering having the ECU changed to up the rev limiter on my '86 MR2, to maybe 8,600 to 9,000

Have you done this or considered this? Cost? Opinions?

Steve Burns
ITB MR-2
Midwestern Council

[quadzjr]

IMHO It doesn't make sense to bump it up that high.. the motor simply cannot breath that high becasuse like what chip said, with factory cams being so small and have absolulutley no duration. It is sad when a stock honda d16 cam looks like a monster racing cam in comparison to the stock 4age cam. . However if you are say building a GT or Prod car, this is very good thing to try out.

[raceita]

Steve, I understand no HP gains, I'm looking for flexibility. Some tracks I race at it would make sense to hold a gear rather than upshift just to downshift two seconds later.

Steve Burns
ITB MR2

[Chip42]

motor is good to 9k, you shouldn't need to worry about that. But don't just change the crystal (xtal) in the ECU to raise the limit as timing changes will be off throughout the rev band as a result of the change in the clock frequency screwing all the math. you may or may not see too much of an effect, but be aware...

[Spinnetti]

Thanks for all the replies...

From what I understand, revving the piss out of this motor doesn't do too much for you either, but my rev limit is about 8300, and it pulls smooth until there.

I guess I just need to get the fuel and timing right with the stock ECU and call it good.

[Spinnetti]

There is a good write on this on the http://www.mr2oc.com webiste. There are alot of people that installed stand alone systems like a megasquirt, and saw minimal gains.

I guess I should have known to check there - I have a couple of my MR2's posted there (I did a MR2 Roadster and a 20v vvt motor version)

I've never road raced any of my MR2's... Bit off topic, but would you be willing to share any alignment and/or spring rate tips? I'm planning to build one for the 24hrs of lemons, and not sure what a good baseline is on rates & alignment..... I'll move the battery to the front, whack the roof off and fully tie in the cage, otherwise mostly IT spec.

[quadzjr]

What type of suspension do you plan on running for your MK1? There doesn't seem to be a "racing" suspension option out there other than custom coil overs. There are a few "sport" options out there.

You mean you want to do one like the one that was at the last 24hr lemons?

[raceita]

Spinnetti, I run 2.2 camber front, 2.5 rear on Kumho V710. Sport springs (no coil overs). I don't remember spring rates.

You're rev limiter is at 8,300? Mine is 7,600 (stock). How'd you get 8,300?

Any advice on how to get a higher rev limit?

Steve Burns
'86 MR2 ITB
Midwestern Council

[Spinnetti]

Steve, thanks for the info.. that's about what I thought, but wanted to check with somebody else....

I'm not sure how the Rev limit was set. My understanding is that the ecu is stock otherwise, and there's no sign that its ever been opened up. The last version of my car had some high profile Toyota/TRD and SCCA owners, so I'm sure they had some resources at their disposal.

[Spinnetti]

What type of suspension do you plan on running for your MK1? There doesn't seem to be a "racing" suspension option out there other than custom coil overs. There are a few "sport" options out there.

You mean you want to do one like the one that was at the last 24hr lemons?

Funny you should mention that one... I was in a Celica at that race, and that MR2 and I traded spots probably 100 times or more over a 90 minute or so stint- it was really fun. Thing is, that MR2 should have been faster, and certainly a lot faster than the Celica I was driving. In an enduro you can't run a ton of camber and not have wear issues, but I think that one needed more roll control at least.. If I can't come up with another AE86 Corolla, I'll build the MR2 and we can compare notes at the next lemons