Tuning the Fit for Acceleration
 

Hi everybody. I have an '08 Honda Fit Sport AT. I want to tune it for acceleration. Please see my signature for my list of mods that I currently have on the Fit. What else can I do? I was thinking of changing the exhaust headers but I heard that decreases low RPM prformance.

Apparently DC Sports Headers give a good boost of torque in the low end \ Mid range!! i think you could consider it!!

Marko!!

It does? I've been considering DC Sports headers. But what about other brands of headers? Don't they all do the same thing?

And how loud would the addition of DC Sports headers be? I don't want to be pulled over by the police constantly. I live in CA, USA. They're pretty strict on that.

I think that as long as you retain the stock Cat Converter, you will remain silent... it didn't made more noise on both my 626 and neons so i don't tkink it would on the Fit... some says it reduced noise!!

As for the headers, bigger and\or shorter tubes will shift the powerband in the upper revs, smaller and\or longer tubes will create more low\ mid ragne... the design of the collector plays a major role also...

Read this!! -> Intake & Exhaust Systems - Tech - Sport Compact Car Magazine

You may also want to remove the rear seats, spare tire and jack... it could remove near 100 pounds of your car...

Marko!!

i have dc headers
they aren't noticeably louder (with skunk2 60mm)
low end torque is much better (very noticeable)

lighter wheels.

I haven't ruled out putting an aftermarket header on my car, but my past experiences with motorcycles and cars have me almost totally convinced that unless there were other extensive modifications performed, the gains to be experienced would compromise the lower RPM torque advantages that is the strong point inherent in the engines design. The stock exhaust manifold is a tube type system, and by design a header by popular definition. Larger tubes will tend to reduce the scavenging effect by reducing flow velocity and result in limiting the intake volume that is partially facilitated by scavenging effect during valve timing overlap that occurs as the exhaust and intake valves are partially opened between strokes. The under square bore and stroke design of the engine is better suited to concentrating on on increasing the power in the lower RPM ranges. Changes behind the headers would appear to me to be more beneficial to increasing the flow and in turn improving acceleration. I have heard great things about throttle controllers. I have experienced an increase in acceleration with a Next Level Performance Tri-Phase Module, SRI, and 2 1/2" axle back pipe and glass pack muffler. I think that lighter wheels and the throttle controle is where it will end for my modification.

Get a high-flow cat.

You're right about the largers tubes, DC sports headers have marginally larger tubes (+3 or 4mm if i remember right!) but a much better collector design, than the stocker, that helps boost HP and torque on all the rev range without compromising the low end much!! I also heard good things on that piece...

Marko!!

P.S. where do you connect that tri-phase module??

I have posted on it before, and have found that a lot of people have the idea that it is an ebay type rip off, destroy your engine and condemn you soul to hell sort of thing. I have had it on my car since September 2006 and am pleased to hell with it. I can accelerate up a hill in 5th gear 70 MPH that my Volvo 760 Turbo automatic would downshift on at 55 just to top it at that speed. Check it out at nextlevelracing.com. It will seem like it plays out at the top of the powerband, but that is because the increase through the rest of the power range is so vastly improved. Most of the time I only use 1st 3rd and 5th gears and seldom hit the rev limiter as it is so strong on the bottom there is no need to. The results I have experienced are comparable and may even exeed those that I have had with HyperTech chips and programmers I have on my van and my wife's truck. Being able to use higher gears and keeping the revs down has improved the fuel milage as well.

The module has 4 wires one to a power wire activated by the ignition sensor one to ground, cut 5.6 volt IAT wire and splice one on power side, and one to sensor.

Well, the only mod I see that you have that helps acceleration is the intake.

First question: What does low rpm matter? Think about it. When the trans shifts to 2nd gear at redline, does it drop all the way to 1000rpm? Nope. Drops to the beginning of the 'meat' of the powerband.

Honestly....if you're looking for blazing acceleration, don't waste your money on this car. I'm not being harsh, I'm being serious. n/a mods on this car yield decent gains, but in terms of acceleration, you're still going to be slower than 95% of the cars on the road. Not a big deal, the Fit is still an awesome car, but a drag racer it's not.

Your best bang for the buck without question is forced induction. But again, you're getting to maybe 130-140whp with a basic kit. Not blazing power. Maybe good for 15s in the quarter mile, at best. Still slow.

I will say, do it if it makes you happy, but don't do it if you want to be faster than "x" car, because you won't be.

I'll suggest this: Find a local autocross event and register for it. Attend, have an instructor ride with you a few runs, learn how to autocross. You'll forget how slow the car accelerates really quick!

I recently rode in a Yaris with suspension, wheels and tires. I'm not sure the driver ever had grip at all. 4 wheel slides, etc. But he ran a time faster than I could muster in my S2000 (I'm a beginner autocrosser, though), and he has about 100hp.

I agree completely


But to answer your question you should look into throttle controllers. I believe there are 2 of them and people seem to be giving them pretty good feedback.

Change the gearing, and/or use smaller diameter wheels.

Both T1R and MFactory offer final gear options.

https://www.fitfreak.net/forums/aj-r...inal-gear.html
MFactory Final Drive Gears

edit: n/m - Sorry I just just noticed you have an AT, and these are for MT only.

how much smaller diameter wheels can you get and still get somewhat performance tires? LOL.

195/50R15 and 205/40R16 will get you off the line between 3% and 4% faster then the stock 195/55R15 wheels. A fair number of choices at those sizes.

Of course your speedometer will be off by 3~4% as well.

Actually those sizes aren't that much different then the base 175/65R14 steel wheels.

i dont know if the fidanza lightened flywheel is compatible with the 08 but i really enjoy mine on the 07.

sell your auto and get the manual transmission, but if you sell your fit, you might as well get a faster car.