this throttle body claims to produce 4-5Hp when dynoed. So my question is, if the engine mod i have done to my fit so far is muffler delete ( replace with straight pipe) and a prm racing cold air intake. Then would i gain 4-5hp from that throttle body alone??? thank you for your time guys, im just anxious to make my 2009 5 speed manual, honda fit faster, so far ive removed the spare tire, back seats, and back seatbelts, as well as installed 15 inch konig helium racing rims, however i still have stock rubber, im waiting till i wear them out till i will get new ones. So even with the weight reduction, racing rims, and muffler delete, the car feels fast, i just ordered the cold air intake couple days ago from prm racing and will receive it this coming thursday or friday. Anyways even before installing the cold air intake the car feels fast which is why i cannot wait to install the cold air and possibly this racing throttle body which im asking about. I have the 2009 honda fit lx with a/c and 5 speed manual, silver in color, and 15 inch konig heliums are also silver.

 

all the mods and weight removal so far should make a noticeable difference.
the throttle body on top of that I'm not sure because of a nagging thought.

Didn't somebody here with a GD3 do a number of mods and get into a WOT lean condition?????????

I mean if the duty cycle on the injectors is 95% when stock (WOT) and you open up the breathing to the extent of.........

I may be full of crap here but seems to me I read someone had an issue.

 

well if i ended up not getting enough fuel into the engine, in other words not enough fuel for the amount of air, then that would be a good thing because all i would need to do would be to get a fuel management piggyback system by greddy, then add more fuel, then make some serious gains. On aj-racing.com i believe there is the greddy fuel system managment computer that piggybacks factory computer for the 2009 honda fit for like 350 american dollars i believe, im canadian. I think that would allow you to increase fuel.

 

I would search the forums here for 'throttle body" (I know there is a 9 page thread + some others) search 'lean' and search 'fuel management'

and you could post in the mod forums, here posting in 2nd gen you are way ahead of most people. You need to draw upon the GD3 modders for best info, some very sharp guys there and up to speed on info you need

 

there was one thread about the GD3 throttle body, and about some guy that found one but not really sure what happened cause i got tired of reading.

yes with header intake and all that people have said the car starts to lean out

 

Plus its like $600+, not worth it IMO.

 

Think of your engine as your lungs.

If someone has an intake, and no exhaust, the picture here is to breath in as muuuuch as you possibly can, and then breath out juuuust alittle. try doing that for a few seconds (stop if you get light headed. don't want you dying on me.)

If someone has an exhaust, and no intake, the picture here is to breath in juuuust alittle, and then breath out as muuuuch as you can. try doing that for a few seconds (again, stop if you get light headed)

Now considering you have have an intake AND exhaust your engine is breathing pretty well, as long as the flow is matched (this is why i stress that people buy the same brand performance parts so they can work together as a system because they are made with each other in mind). Now, you are adding a larger throttle body. with this you are losing some pressure and adding velocity. So with these mods, i believe you will notice a nice gain in the top end, while you might lose some down low.

Now there are 3 things that an engine needs. Fuel, Spark, and Air. You have plenty of Air, pretty sure you'll be okay with Spark (maybe an upgrade in spark plugs somewhere down the road), but Fuel is where you might have a problem.


With the fuel, i think you should try and get some sort of A/F reader (doesn't have to be a tacky a-pillar cluster). Have your friend watch it for you as you go from 2,000RPM to REDLINE, NOT FUEL CUT OFF (best gear would be in 2nd or 3rd, no need to break the speed limit, just find a highway on-ramp).

If you see a problem, go ahead and check out the Greddy piggy-back. If not, don't worry too much. Quick Note: Not sure what octane the Fits take (don't own one), but if you can bump your octane up to 91-93, you will notice a nice increase in smoother power.


Also, further down the road if you want to improve your engine, get a Port/Polish and try to find a shop that can balance your bottom end as well. Along with the basic I/H/E you will be good to go until you want to add some serious horsepower. Then i'd look into either a new engine, or forged internals. But the main thing you are looking for is EFFICIENCY. The more efficient an engine, the more reliable HP and MPG you can get from it.

Cast internals are usually reliable up to 300hp. Forged bumps your max reliable HP to about double that (maybe a little more depending on quality)


hope this has brought some light to your future tuning. knowledge is power, and thanks to the school i'm going to, i've learned quite a bit.


if there are any questions, please send me an E-mail. I am more than happy to help. MichaelCoolGuy86 @ Gmail.com

 

Nice post. +Rep for you.

Although the Fit takes regular fuel alot of people say that premium or 91+ octane fuel wont make a difference in our cars.

 

Thank you for the rep points. lol!

yes, this is true. unless your car is TUNED for higher octane, you are just throwing your money away. This is why i suggested that he should check into the Greddy fuel controller and see if it had an octane rating setting.

10.4:1 compression ratio and 16 valves? that is definitely deserving of 91-93 octane!

I'm just guessing here, so don't shoot me if you don't get it... but...

With Intake, Throttle Body, Header, Exhaust (Catalytic Converter still in place), and a tune (the tuning is the most critical part). I believe we can take the Fit's 117HP (crank horsepower, not wheel horsepower) and bump it up to 140-150 HP at the crank (not wheel horsepower).

I believe if you ported/polished the head, balanced the bottom end, and raised the rev limiter up to about 7000-8000 RPM (might have to do some valve train work). I believe that number that i stated before could be raised to 170-180HP (AT THE CRANK).

By the way, the reason i expect such a large increase in power is not because of the port/polish job. but more of the balancing + rev limiter adjustment. If you look at the mathematical equation for Horsepower it goes like this: Horsepower = Torque x RPM / 5252. This is why i believe in the RPM adjustment. IF you have 106 TQ to begin with, and you add these mods in, you must get a jump in torque to atleast 120-140. Now times that by 6,600RPM (stock rev limit). Now times that by 7,000. Now times that by 7,500. Now times that by 8,000. See my point?

If these numbers look weird/hard to believe to you, please call me on it. I'm just guestimating right now. But if you could get 180HP out of a 1.5 liter, i believe that'll put it up there with the HP/Liter rating with an S2000.

 

S2000

14.1 hp x 2.137 (displacement) x 7.8 K RPM = 237HP

The S2000 is already a high state of tune.

Based on the S2000,

The Fit has a theoretical max HP of 143 HP
(may or may not be attainable depending on the flow characteristics of the head and the cast in head exhaust manifold, meaning a tuned header is not possible)

(14.1 HP X 1.497 displacement x 6.8 K RPM= 143HP)

 

i don't get where you are getting your equation. if i had to do it, it would be this: HP/Displacement.

S2000 - 240/2.2= 109 HP per liter
Stock Fit - 117/1.5 = 78 HP per liter
Tuned Fit - 180/1.5 = 120 HP per liter

 

i want to keep using 87 octane if possible and i just want to get my horsepower at the flywheel to 135-140 and ill be happy, thats just a gain of 23 hp from stock and its my goal all while using 87 octane, is that possible with just cold air, throttle body, headers exhaust and greddy piggy back

 

We dont know, theres not enough of an aftermarket yet. Although a header will probably never be available for our cars due to the exhaust manifold and head being one piece.

I think 180hp (150ish whp) will be very hard to do N/A on this engine without spending alot of money or opening up the engine. I think 130whp will be a good goal for a fully bolted on GE. Cant wait till we start getting exhausts and more parts available and seeing some good dynos.

 

I would say its possible. I just don't understand why you wouldn't want a bump in octane. the difference between 87 and 91-93 around here is 20 cents. what... thats 2 extra bucks at the gas station?


Also... Pre-Detonation (Pinging/Knocking) is always a concern. Why they have 10.4:1 compression with 87 is sort of a mystery to me. I'm guessing they just retard the valve timing. My MX-5 has 10.6:1 and it comes tuned for premium stock.


Main problem with timing, octane, etc is that when you advance the timing too much, or have too high of a compression ratio you get pre-detonation (knocking, pinging, etc). Pre-detonation is basically your gas combusting before your engine wants it too. All automotive cars are 4-Stroke motors. Intake, Compression, Power, Exhaust (these are the 4 strokes).

Intake: The intake valves open and the engine sucks in air. The piston is at Bottom Dead Center (BDC)

Compression: The mixture of fuel and air get compressed. The piston is at Top Dead Center (TDC)

Power: The compressed mixture gets ignited by the spark plug, sending the piston shooting downward. This is where the piston is at BDC again.

Exhaust: The exhaust valves open and the engine pushes out the air as the piston is on the way back up. This is where the piston is TDC.


Makes sense so far?

So basically, imagine the fuel is half on the way up Compression stroke... and without it being at TDC, it combusts. When this happens. That happy little piston that is trying to go up all the way, gets beat over the head with a baseball bat thats trying to send it right back down. Now your piston takes some abuse even when working normally. But imagine its trying to turn the crank counter clock-wise because of the precise timing of combustion... then all of a sudden a pre-detonation comes along and smacks it before its suppose too. Basically while all of your pistons, rods, crank, etc are trying to go left. ONE piston wants to go right... sounds bad doesn't it? so thats why is suggest 91-93 octane. Especially if you are going to be modding.


Why put all that money into your car... and skimp out on a tiny 2 bucks extra at the pump?

 

wait... what? the head and exhaust manifold are one piece?! what the hell!? i'm going to a honda dealership in the morning, i GOTTA see this!

Are you sure its not just the exhaust manifold and catalytic converter that are 1 piece? thats the same on my MX-5. If you want a header, you're doing it illegally.

 

Yup the new 09's have an integrated exhaust manifold

 

that seriously sucks... why the hell would they do that? oh well. guess you guys already know what the aftermarket are going to be working on.

"Introducing the all new 09+ Honda Fit aftermarket head + header!"

it'd be badass if you could rig up a K20A head onto it... doubt it'll happen though.

 

Well a Formula 1 engine (2006 rules) is 2.4L and produces 780 HP,(325 HP per liter)
how does it do that? It spins at 18,000 RPM is how.
Think of an engine as an air pump. Displacement alone wont move any air.
But if you spin the pump it moves air. And the faster you spin it, the more air it will move.
The electronics, the motor, nothing on the Fit is designed to work at S-2000 RPM.

My 1 liter 4 cylinder snowmobile produces 165 HP (basically a Yamaha R-1 motorcycle engine) but again, it is producing that at 11,800 RPM. That engine happens to flow very well as it has 5 valves per cylinder and titanium headers.

 

I think what he was trying to say that if we do get the L15 to 180hp to the motor it will have the same power/liter ratio as an S2000. Whichever way it gets there.

And supposedly HKS is working on a turbo kit, not sure what theyre gonna do with the manifold...

 

No, he has the S-2000 at 109 HP per liter, but somehow figures the modded Fit at 120 HP per L......and completely disregards RPM (or disregards that it would cost a fortune to make the L15A a 8000 RPM engine, putting in a K20 swap would be far more cost effective)

180 HP for the Fit without turbo/SC is a complete pipe dream.

143HP would be about the max (the cast in header, and the resonant chambered intake manifold tuned to 3500 RPM may make the 143 HP impossible though)

pics and diagrams of 09 Fit intake and exhaust manifolds here
2009 Honda Fit - Powertrain - Honda - Press Releases - Selected Story


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