Modify the EPS is it possible?
 

Hi,

After my first race in a spec series (with no steering aid) I need to admit that I don't like the feeling of the steering wheel of the rx8.

In fact I think it is not so communicative and I would like to change it a little (less aid) also because I use the car mainly for track events.

Searching on the forum nothing raised and I would like to know if it is possible to change it and how.

Thanking you in advance

Best Regards
Davide

Aggiungi un potenziometro :)

Short answer: Yes it is possible. But I don't know how.

:)

Longer answer:
From my discussions with another forum member that I met in person, I know that modifying the amount of electrical assist on the steering rack is a matter of simple numbers. This other member (as a hobby) hacked and decoded his 2004's ECU, and one of the things he listed as 'exposed' was a table for the electronic steering assist levels. Since a table exists, modifying that table should be possible. In theory, this should be a table that could be modified with the AccessPORT, however, I've never even heard a peep of anyone attempting to or even discussing it on the forum itself.


From discussions relating to power steering failure, I believe it should also be possible to completely kill all steering assist, possibly through disconnecting the sensor harness? I personally wouldn't play around with that, but just tossing it out there as an option or thought. I'm guessing that this would be overkill for what you are trying to do however.


Hopefully this helps you in the right direction.

Sorry to raise this from the dead. BSE, have you done this successfully on the '8? Does it affect the dsc operation?

Does anyone know what tuning software can access/modify the EPS tables?

relevant:
AutoSpeed - Modifying Electric Power Steering

The AP can't do it but PM Brettus and ask if he knows if mazdaedit can do it.

As stated previously, it has it's own separate pcm

Oh yeah, :doh:

I did it for a while, then went back to normal. If you lower the potentiometer too much weird things begin to happen :scared:

Can you elaborate? Did weird things start happening in "reasonable" ranges of steering effort?

Where did you place the pot(s)?

http://www.rx7club.com/attachments/3...-rx8_eps_2-png

Weird things as it started working intermittently like it does with loose\oxidised connections.
We linked the potentiometer to the wires that actually power the unit just to play with the idea. Since it didn't work too well we decided to keep it stock.

Which unit? I wouldn't think a regular pot could survive the power level going to the actual assist unit. I was thinking of altering the torque signal to the eps pcm. Did you investigate this approach?

I honestly can't remember. It was 2011 and I stopped driving the rx8 shortly after those tests!
Neither I nor vcoil investigated it any further :(

consider using a smaller steering wheel instead ...

Street car -> no cage -> no harness -> keep airbags. Are there any smaller diameter steering wheel options that retain the airbag? Offsetting the wheels outward should help.

Does anyone know where I can buy an extra N-05 connector?

https://www.rx8club.com/attachments/...eded-photo-jpg

https://www.rx8club.com/attachments/...ed-photo-2-jpg

Thanks

Interesting, nice find.

Anyone tried this in the RX8:

https://www.autospeed.com/cms/a_111532/article.html

did you not read the thread, or perhaps your comprehension of the english language is not sufficient to comprehend what is stated?

I read that the same link I posted just now was posted before in 2019 (but is not working). After this there was no answer, so I do not think the question if anyone actually tried this on the RX-8 is so absurd that it can be explained with insufficient english comprehension only...
Post 10 tells me the author installed a potentiometer to the actual power unit which is not the method described in the link I posted.
Many comments I read by you do not contain any useful information but a grumpy and offensive undertone. I guess no one needs that, I don't for sure...

ok I see

it’s the same thing that was discussed and tried in 2013; the link address just changed, which is not unusual over that amount of time.

imo you’ll just be tinkering with something that isn’t going to result in anything meaningful. I have no issue at all with the steering; light in low speed parking and suitably stiff, but not unreasonably so, at speed.

there’s a thread on here about eliminating the power unit by gutting it. Imo this has the most potential for a track car. The issue is that you do need gut the electronics fully in both the rack and the pinion, yet also provide support the rack in the main body with either bushings or bearings. If the electronics aren’t removed from both then there is way too much drag/stiffness. The question is how stiff is it in fully modified form. There hasn’t been much on it, but supposedly somewhere in between the two. The benefit is that it’s both lighter and reduces the alternator load on the engine output.

I was trying to get my hands on a failed rack to experiment with gutting it fully, but nobody ever came through on one for me. I don’t really want to gut a good rack.
.