i'm boosting an auto rsx. 20psi, 280+whp. The Fit's auto trans has the advantage of having the sportshift function, which allow more control over the gears, before shifting, u can let off the throttle which will blow off the boost before the shift, then shift. The shifting of gears will take place when the boost is gone. Much like a manual trans, but not as quick of a shift.

Also, this is a supercharger we're talking about, not a turbo. Superchargers are a lot less stressful to the trans versus turbo setups.

 

i always have wanted to ask you about your k20 build, as it is an auto (and a 5 speed no less, like ours) and its what many consider the 'lesser' k20. (not my opinion, i think its a good engine!) So your tranny has held up fine under that much boost?

I totally agree about the less stress forced on the engine from a supercharger as opposed to a turbo, and the rotrex is even less stressful than traditional superchargers. But apparently, something about the fit, be it the engine or tranny, makes anything more than 5psi kinda sketchy. i wish there was a way we could get a sort of 'mid boost' belt, maybe something along the lines of 6-8 psi.

boosting that much to me would be perfect.

OJR: on the kraftwerks website, it shows a new dyno icon on the auto fit's page, but when clicked on it shows nothing! do you have any auto tranny dyno's?

 

its not the amount of boost that matters most in this case, but the HP/TQ rating. RSX is a daily driver, boosted and beated on since 49k miles, now sitting close to 81k. still stock motor. Building a motor on the side (very slowly, lol), and have an a2 head swap lined up. I've been using full Amsoil ATF and trans cooler. My stock dyno was 120whp, now sitting at 280+. Thats more than double than stock. Keys to longevity: Tune, and MAYBE the fact that the RSX auto has sportshift (like the Fit) where i can let off boost before i shift to the next gear, so the transmission does not see the excess torque during the shift.

Have there been problems with Fits over 5psi? I'm not understanding what you mean by it "being sketchy". If not, keep going until u reach 200whp with no worries in mind and making sure u have a solid tune. Slushboxes are becoming more efficient than it was back then. And superchargers, no need for letting off before the shift. Heck, 150whp in a Fit will fly anyways. One word of caution, once u boost, all your worries will be tossed out the window and you will want more and more boost and power. Thats a 95% guarantee. You may think u'll be happy, but nooooo. LOL, look at JDMChris, keeps going and going.

My bro has a supercharged automatic Scion tC. (in sig) originally was a 5psi pulley from TRD. We got a custom 12psi pulley made and tuned it, and baam, more power, no problems. Needs a ATF drain/fill soon though.

 

I was reading in the latest honda tech about how they managed some 500hp out of a stock b.16, with only pistons and i think a new fuel rail. And like you , they said the key was in tuning.


I said 'sketchy' because most companies making bolt on turbos/superchargers havent exceeded the 10psi mark, and there are virtually no internals made for our cars, unless one was to go custom. And again, most of these kits come pre-tuned, and it doesnt seem that they can be tailored to tastes.

I agree that auto's have come a long way, and i don't think 150 whp is going to be an issue, even for an auto fit driver.


i do wonder how i'll get up that far though, as even a manual transmissioned fit, with a cat delete, 5psi charger with injectors, and exhaust has only made about 144whp, and the auto will be a bit less. Any reccomendations? would upgrading to the 10lb pulley, despite kraftwerks previous posts on how it will not be available to auto guys be of any help?

any suggestions would be appreciated, and i'm sure a lot of the other auto fit drivers would appreciate it too!

 

yup, the HP is not enough to warranty any concern.

most companies dont make turbo/supercharger setups to go "high" as they dont want the liability of it either. Thats why theres boost controllers to up the boost, but its your responsibility to get tuned to match the added boost.

The only problem i see with the added boost with Kraftwerks is that they dont have a tune for it. You can always add boost via pulley or whatever, the real problem is the tuning solution as u need the tune to match it. Which is why they said they are going with Hondata to make the reflash for it. Since the motor is the same, i do not see a reason why the reflash would not work for the auto. (i've worked with Hondata in making the manual rsx's K-Pro standalone work with the auto) if anything, u should be able to piggyback the manual Fit ecu with KWSC reflash to the auto ecu via custom wiring harness. Auto ecu controls the trans, manual ecu controls the engine.

But lets wait and see! They haven't even finished with the manuals.

 

sorry to clutter the Kraftwerks thread! thanks for the move!

 

I'm confused about this thread. Is there a question being asked for discussion? lol, sorry, I'm extra slow today

 

This was in the Kraftwerks thread, but removed and made its own thread.

 

whoa i didn't realized this had happened! sorry for the clutter.


but since i kinda started the discussion, i'll ask an official question so people don't look at this thread and say...'huh?'


would a high boost auto fit be possible? is the auto tranny in the fit not as hardy as honda's of yore, and would buckle under pressure, even from a supercharger as efficient as a rotrex?

i'm not expeciting a complete explanation, but speculations as to why its not being done are more than welcome.

 

since the tune is through the ecu, can the kwsc be controlled the same way? can an ecu signal control the kit supplied bypass valve? since the a/t shift is controlled by the ecu, can the ecu send a signal to the bypass valve or maybe an added blow off valve to activate and relieve the boost long enough to shift? thats where i'd think the weakest point in the trans would be-the shift between gears not being engaged in each gear. but i've never done any tuning, so i might be dreaming....

dave