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Adding Supercharger, looking for best way to tune my fit
I will be undertaking adding a supercharger for my 2nd gen fit sometime mid February. It was a pain to find a supercharger (I ended up buying it on ebay used, 15k miles) but I finally got one and I'm super happy. This will go along nicely with my recently installed yonaka exhaust. I also picked up a AEM fuel pump, Koyorad all aluminum radiator, speedlabs header + b-pipe one piece which I'm going to install as well.
This will be my first time doing a significant engine mod, and I'd like to do it right in terms of tuning the car. After I install the SC and all the other parts (assuming I don't blow up the engine) I'd like to ensure a good tune alongside it. I'm willing to take it to a shop, and/or buy a ktuner to get the job done.
For folks experienced in tweaking the fits tune - is buying a ktuner worth it to tweak my car personally or should I have a shop do a tune on it, or both?
Here is the tuner I'm thinking of getting, I'm also open to buying a different one upon recommendation. Thanks in advance for your help.
Well, doing it yourself means, the more experience you have with it, the more confident and/or chance of getting the best out of it.
If you're not already a "pro," then a shop that normally does it is likely to get a better tune out of it.
On the other hand, I'm running my Sprintex with just the stock ECU (the piggyback died a while back)... so, if you experiment gradually and not do anything utterly stupid, it might be worthwhile to do it yourself as a learning process.
Well, doing it yourself means, the more experience you have with it, the more confident and/or chance of getting the best out of it.
If you're not already a "pro," then a shop that normally does it is likely to get a better tune out of it.
On the other hand, I'm running my Sprintex with just the stock ECU (the piggyback died a while back)... so, if you experiment gradually and not do anything utterly stupid, it might be worthwhile to do it yourself as a learning process.
Thanks for the reply! I'm definitely not a pro but I'm willing to put in the time and effort to do this right. I care a lot about my little egg and want to make sure the engine will last me a long time.
I'm assuming you didn't get a tune? After you installed your SC did you get a tune from a shop or do a tune yourself?
I just called a recommended tuner via my brother, and he recommended I get a Hondata tuner over a Ktuner, with no specific reason why except that it's easier/better to work with.
KTuner is your only option for reflashing the GE8 at all. Hondata is currently exclusive to the GD3 (first gen Fit).
The only major draw backs from KTuner compared to Hondata is the lack of live tuning. Otherwise, its relatively well laid out and fairly straight forward to use from the little bit of tinkering I've seen and done with it on other Hondas. Mind you by no means that I'm savvy with it though, KTuner is relatively new to me.
Thanks for the reply! I'm definitely not a pro but I'm willing to put in the time and effort to do this right. I care a lot about my little egg and want to make sure the engine will last me a long time.
I'm assuming you didn't get a tune? After you installed your SC did you get a tune from a shop or do a tune yourself?
I just called a recommended tuner via my brother, and he recommended I get a Hondata tuner over a Ktuner, with no specific reason why except that it's easier/better to work with.
When I initially got the supercharger, I used the base tune that came with it and I was part of a forum thread that involved one of the Sprintex folks that would do the tune and pass it back to us based on communication from us. I tried out some of the tunes that were created and tried to learn a little. And it was right before piggyback died, that I was told that even if the piggyback had a zero tune, it should run fine, just not "optimally." So, when the piggyback did die, I eventually just went with just the stock ECU.
Update on my progress, I finally had enough free time and vacation to install my supercharger and associated parts. I have now a new issue that I haven't figured out yet (P0335 CKP no signal) but I'll save the inquiry at the end.
My progress:
We installed the radiator, fuel pump, full exhaust, and the supercharger exactly as specified in the manual. I didn't really take progress pics (apologies) but I do have some video of our initial fire up and tune experiences. I did keep the piggyback SM8TL but I feel it is the source of my latent issues I'm having with my crank sensor issue.
My tuner did one more run and he managed 163hp/133 Torque.
Now, my current issue that I'd like help with from you wonderful folks.
After I got my setup tuned and drove the car home, everything was running great, did a couple of pulls and my fit was singing beautifully down the highway with no issues.
The next day, I fire up the car with no issues then I proceed to drive and the engine cuts off and can't rev past 3k rpm, and check engine light goes on P0335 CKP no signal.
Baffled, I go and replace the sensor thinking it just happened to die on me. Turns out the sensor was fine so I check the harness it's connected to, that is also fine. I spent hours taking apart the supercharger and quadruple checking all my work and seemingly I made no mistakes. The only other thing I haven't ruled out is the SMT8-L piggyback unit as I've learned that it has a crank signal output that might be bad, but I haven't had time to check.
Has anyone else hit this issue? I'm kinda out of ideas and might start looking for an experience electrician soon to help figure this out.
Update, my SMT8 piggyback died on me and reverting my harness back to stock fixed my P0335 CKP sensor issue. I'm going to have to omit the extra fuel injector in my setup and get a re-tune.
Another thing that happened was that my driver side motor mount started squeaking a lot and found out it was on it's last legs. I bought innovative mounts 75 to replace them. The passenger side mount is an absolute PITA to position and screw down even with having the motor on jack stand and loosening the other 2 mounts. I needed my brothers/dad's help to crowbar the engine into position in order to get the bolts in. Car is now a lot noisier in the cabin, but holy hell is my acceleration much better and smoother. .
I've been silently looking at this thread. Thanks for keeping us updated and posted on your build. I'm definitely interested in going this route someday.
You're definitely better off without the piggyback. It will run best with 4 proper size injectors (stock 310cc k20 injectors) and a custom tune via Ktuner.
You're definitely better off without the piggyback. It will run best with 4 proper size injectors (stock 310cc k20 injectors) and a custom tune via Ktuner.
Thanks for the reply! Do you have a specific part number you could share? I've seen folks use the Acura RDX injectors with some clips, but I'm not sure what clips they used or if they are compatible with the fuel rail harness without additional adapters. Most of the posts I've found are outdated and links are broken.
I added an Injen CAI with a hydroshield on the filter since I live in wet weather PNW. I tried to remove the gross red paint the previous owner of this sprintex had haphazardly painted on with little success. Will cleanup better next chance I have some time.
I struggled for a few hours to find the Crankshaft Position Sensor (CKP) and the Camshaft Position Sensor. Here's a pic from under the passenger side axle with annotations in case folks stumble on my thread scratching their heads looking for these things. The CKP sensor is behind a small heat shield that's held on by a 10mm bolt (black on my car)
Here's the wiring job after reverting my harness back to stock, soldered everything and added a heat resistant loom to avoid future issues
Innovative motor mounts:
Transmission (driver) side mount It was relatively easy to replace this one. Nothing some extensions and elbow sockets couldn't reach. It took a huge effort to get the mount into position. When I first got it bolted to the engine bracket it was about 3/4 of an inch off from the frame threads. I had to loosen all of my other mounts and with the help of my dad/bro we used pry bars and clever leverage to get it into position enough to bolt it down.
Thanks for the reply! Do you have a specific part number you could share? I've seen folks use the Acura RDX injectors with some clips, but I'm not sure what clips they used or if they are compatible with the fuel rail harness without additional adapters. Most of the posts I've found are outdated and links are broken.
Unless you plan on stepping up the power a fair bit, the 410cc injectors are larger than you need. They can be used, but are really meant for 250+hp. The OEM 310cc injector number is 16450-RBB-003. Those are what Honda uses in 200-220hp applications, so they should be what you need. OEM injectors are pricey, so you may be better off just getting quality aftermarket replacement injectors. Here's a link to RockAuto offerings - https://www.rockauto.com/en/catalog/...+injector,6224
I don't think you will need the injector clip adapter with those, but I definitely could be wrong. I'm running some Bosch injectors that a local shop sized to 310cc in my Fit right now with an adapter clip. Runs fine with low duty cycle. Has plenty of headroom for boost in the future.
I've heard nothing but trouble with fitting the Innovative mounts. Glad you were able to get them in!
I need mounts for my GD, but don't want to spend the $1,000+ for OEM mounts, but also don't want ones that are a PITA to install. I'm also scared about putting too much strain on the timing chain cover. That's all the one mount connects to and some have torn the cover.
I bought the adapters on ebay, but I got the injectors from the hondapartsnow.com
This 2nd tune I did was much better. He found a few leaks in my plenum and EGR flow and plugged them up with custom fabbed block off plates. My spark plugs got fouled up after I tried driving the car with the RDX injectors so I had to replace those. My new tuner gapped the fresh set of spark plugs to 0.032 and he tuned my car.
I gained about 5 hp and 13 ft/lb torque from changing the fuel injectors. So far so good. Running without the 5th injector and piggy back was holding me back a bit. My new tuner mentioned I could gain some significant HP if I could wedge a heat exchanger between the supercharger and the engine, but not sure if that's something I can find.
I also bought some knock off spoon rims and slapped them on. I'm in love
01-07-2021, 04:20 PM
