FB_rad

High torque starters in Santa few springs California.. They will build you any custom starter you want ..

FB_rad

http://www.hitorque.com/

jackhild59

iTrader: (7)

Next step is for someone to video cranking with the 1.2 kw starter vs the 2.0 kw starter, same day, same temperature, same car same battery state etc.

Proof that the change makes a significant difference.

j9fd3s

iTrader: (3)

we know this, the Rx8 started life with the 1.4kw motor, and was upgraded to the 2.0, and then a 2.4. it makes a huge difference in cranking rpm. the Rx7 doesn't need it as badly, but its totally noticeable

cranking rpm goes from ~220 to ~260 to close to 300

Jeff20B

iTrader: (13)

That means the 2.4kw RX-8 motor will fit in the FD and NA manual nose!

Well I think that about does it for me. Now I'm on the lookout for an NA FC 2.0kw motor or the upgraded RX-8 motor. Not because I need one, as the engine still starts even with slow cranking, but because it's cool and I've got the battery cables for it. Relocated battery with 2/0 positive and 1/0 negative. I had the cable so I was like why not? My slow cranking has got to be the old starter, not due to the cables. It could be the battery, maybe.

Just a quick update. I swapped the FD 1.4kw motor onto the NA nose and installed it in the car yesterday. Gonna test crank after I throw the charger on the battery. It sat all winter.

j9fd3s

iTrader: (3)

yeah there are two issues, one is that we're all using old/badly remanned starters, and then there is an upgraded motor.

a carefully rebuilt stock starter does work perfectly fine.

Jeff20B

iTrader: (13)

Yeah my NA starter is definitely old and a reman. The flywheel driver gear shows the slightest bit of wear you can see when the light hits it. But the solenoid is fast and healthy. It looks to have been replaced and has copper studs. I'm not sure when the OEMs switched from steel to copper studs. Some time in the 80s? 90s? Original starters from the 70s had steel studs.

jackhild59

iTrader: (7)

Well, maybe so, maybe so. But what about the weak battery on a low compression engine or the weekend car that has a little voltage drain? Does the increase in current pulled reduce the available cranking time if the engine doesn't start the first try? Just wondering.

I've only had 4 FC's, 2 s4 turbos, 1 s4 N/A and my S5 Vert. I've replaced two non turbo starters with Orielly remans. They have worked fine with no problems.

Dak

This is nice info to know since I have an auto starter laying around that when mine goes I can just swap out the motors.

j9fd3s

iTrader: (3)

see we have vast experience with the faster starters on the Rx8, its pretty much the only way they will start hot, if the engine is borderline on compression. for instance if you have an Rx8 that has a weak engine, hot cranking time goes from ~60 seconds, to like ~6 seconds. huge difference.

if you had an FC that had a tendency to flood, the faster starter will probably help a lot

fbse7en

Let's not forget that the rotors themselves are turning slower than the e-shaft, right? IIRC, only 1/3 of the e-shaft rpm's, assuming the OEM spec 1.2kW starters are spinning @ 220/3= 73.3 rpm's for the rotors themselves.....which is REALLY low!

jackhild59

iTrader: (7)

If this is the case, then a standard must do when rebuilding an engine would be to upgrade the starter. What a great aid in starting a non broken-in engine.

fbse7en

I bet if we could find a starter that cranks out a minimum of 600rpm (900-1000rpm would be perfect, lol) hard/flooded starting issues would vanish completely. Maybe we could even petition Mazda on the issue..

lduley

iTrader: (1)

Lol wut?

Petitioning mazda on anything rotary related, they would just laugh it off, last rx8 was 4 years ago? All the dare to care is making the parts for now. Unless they actually come back out with a rotary powered car again, which is already slim chances. Granted they hold some new patent's on it, but for all we know they are just doing that to seal the deal that only they will make the engine, or have any last remaining rights to it

lastphaseofthis

iTrader: (8)

i have a 120k mile rx8 with about 1700 miles in the rebuild... i changed over from a 1.4 to a 2.0( that was load tested at 2.3 actual power) and it sounds like it went from 200 rpm to 400 rpm. what a huge difference, it cranks darn near instant now... going the high power starter in my turbo and see if the engine will come back to life( its only ever ran twice when i pull started and popped the clutch..)

you think the rx8 starter will direct replace the turbo starter.. thats what i've gathered from this thread... i mean i use turbo clutches/aftermarket flywheel for the rx8( they're the same but cheaper)

driftxsequence

iTrader: (8)

nevermind I'm an idiot.

Rob XX 7

iTrader: (8)

I put a gear reduction starter from a SBC in my vert and when I turned the key to start it the whole car did a 360

cluosborne

I have something to add. I got a 2KW starter motor for a 2004-2008 RX8--specifically this: http://www.ebay.com/itm/251687334839?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT--intending to swap the motor over to the S4 NA manual starter motor nose. The RX8 motor's gear is 2mm too wide to fit the gears in the RX7 nose. The gear diameter on the S4 NA motor is 16mm. The RX8 is 18mm. There are also a few more teeth on the RX8 electric motor gear versus the RX7 motor (the motor itself, not the assembly).

Also, swapping the guts from the RX8 into the RX7 nose won't work either. While the shaft diameters are the same and the teeth width seem close enough, the clutch that the gears ride on won't go down into the nose.

I plan to get the NA automatic starter and swap the motor from that.

j9fd3s

iTrader: (3)

Mazda is the one that offered the faster starters in the first place. they went from 225rpm to ~280rpm and then 300rpm in the late Rx8. if your engine can't start with that, something is majorly wrong

lduley

iTrader: (1)

Ya, i've heard engines run at 400rpm, hell i got a old cast iron kohler single cylinder to run at almost 300 rpm

lastphaseofthis

iTrader: (8)

my rpm needle in my fc now moves faster when start, then it does in when i slip it into 5th crawling thru a parking lot. which means me engine will run at lower rpm and make enough power to accelerate into the power band, then when i actually start the car.
yes i can drive from 5mph to 45 without down shifting from 5th... just for fun.. if there isnt any hills.
that was with a motor with like new rotor housings, and only 8k miles on it... i later blew that engine. ( too much boost)
which begs the question.. did the 2.0 kw starter just cover up really borderline blown engines? i think so...

REW138

@bumpstart
I apologise for bringing this back from the dead.

Coming over from Ausrotary and Reddit.

Is there a comprehensive final list of compatibility when it comes to starters?

I have an S4 NA Manual, and after a rebuild it's a slow startup. What would I look into?

wilfff

@REW138

I upgraded my starter just last month and I was looking into the same thing. I have an S4 NA Manual as well.

I ended up getting an S4 Auto starter (2kW) and swapping the nose and drive gear from my S4 NA Manual starter onto the new S4 Auto body & motor. Start up is now much better, but to be fair my original starter was probably on it's way out.
Swapping just the nose caused a grind, I had to swap both the nose and the drive gear.

From reading posts, I think the RX8 2.4kW starter will work but you may/probably have to do so the same nose & drive gear swap (Disclaimer. I never tested this). This was the route I was going to try, but all the 2.4kW starters I saw were much more expensive, so I settled with the 2kW.

I believe Banzai sells a version of their high torque starters for S4 NA Manual if you don't want to deal with swapping noses & internals.