Assuming the Fit would have 180hp then it will have 120 hp per liter. And maybe he was getting confused with an AP1 S2000 which has a 2.0 liter engine and 120 hp per liter. I dont see what rpm has to do with hp per liter ratio. Sure RPM is the main reason these small displacement engines can make that much power and 180hp might seem like a stretch, and spinning an L15 to 9000 rpm wont make as much power as an S2000, but he is looking at purely hp to liter ratio.

237 hp / 2.0l = ~120 hp per liter
180 hp / 1.5l = ~120 hp per liter

Although I agree that 180hp (155ish whp) NA is pretty darn impossible without a major engine build.

 

Yes, a 180HP 1.5 engine is a bit of a stretch. Yes it would be a little expensive. Is it possible with the right tune? yes. I didn't say it'd be easy. I even safe-guarded myself by saying that you MIGHT not get that much HP, and you MIGHT need valve-train work.

But lets look at it this way.

Honda Civic Type R in the late 90's.
185 HP. 110 TQ. 1.6 liter. 16 valve. 10.8:1 compression. higher octane fuel. stroke: 77.4mm. bore: 81mm.

Honda Fit in 2009 (over 10 years of technological advances)
117 HP. 106 TQ. 1.5 liter. 16 valve. 10.4:1 compression. lower octane fuel. stroke: 89.4mm. bore: 73mm.

I honestly don't see that big of a difference. An engine is an engine, is an engine. Get the right camshaft, the right octance, the right VTEC settings, and the right flow through the head... I believe you'll be good to go.

I see your point on the RPM's. larger stroke = less reliable high rpm's. So lets look at the HP equation again. HP = TQ X RPM / 5252. So we drop some RPM, and because of the stroke, there is a possibility for more Torque.


I believe my asessment of the Honda Fit's engine was correct. I was unaware of the Head/Manifold situation. But i believe if you do what i have said. There is a possibility of making 180HP.


By the way, i double checked my sources... the Civic Type R really only had 110 Torque... i was shocked too.

 

....sorry, I don't know how to explain it further. Other than to say take away RPM and the HP per liter = Zero

If somebody wants to make a 120HP per liter NA 1.5 Fit motor, that's fine by me

 

Please explain if you dont mind, im curious about your equation. I understand the equation that relates rpm to horsepower and torque, but not the one that involves rpm in a hp per liter figure. I mean if an engine has 100 hp and a 1 liter engine what does it matter if it revs to 1000 or 15000 rpm? It will still have a hp to liter ratio of 100.

 

no no, there must have been a misunderstanding. the HP = TQ x RPM / 5252 is a seperate equation from my HP/Liter equation. They are no way related. i was simply showing that a 1.5 that is tuned can relate to an S2000 in certain ways.

If you get out a calculator and you have a 2.0 liter engine with 200hp (like the civic SI) you will have 100HP per liter. if you have a 2.2 liter engine with 240HP (from the newer S2000's) you will have about 110 horsepower per liter. now lets look at a 117hp 1.5 liter engine, you do the same math. You take your overall HP and divide it by your Liters. Thats why i said... if you have a 180HP 1.5 engine, it would have a close to (if not better) HP/Liter Ratio (One of the facts that Honda used ad a selling point for the S2000)

Take a 4.6 Liter V8 from a Mustang... 300 HP... do the math, and you'll laugh your butt off. the HP/Liter ratio is a bit weak (65HP per Liter).

The RPM thing is something different. don't worry.

 

Right thats what im saying. Tork is saying that rpm has a factor in the hp per liter equation, which is getting me confused...

Weve strayed pretty far off topic :/

 

Where in the RPM an engine has its peak horsepower can be changed drastically with thousands of different variables. I believe there was a misunderstanding between Tork and I. For that i apologize (its 4:30am over here right now).

As i posted before though, i don't know where he got that equation from. Tork might be able to explain it to you later. Until then, i'm off to bed! i probably won't be as active in this forum in the future as i am now. So if you, or anyone else, have any further questions, your best bet is to IM me on Yahoo or AIM.


I just hope that i've shared some information that will help you or anyone else further down the road.


good night.

 

Im pretty sure Tork was just explaining how engines use RPM and displacement to achieve a certain hp. When all we were referring to was simply HP/L. Correct me if im wrong.

Thanks for your contribution michael.

 

Mr. Brown, welcome & thanks for your input! However I'd say there's a major H.P. hurdle here; those "advances" you've cited are all in the following catagories over most previous Honda engines: emissions, cost of production, reliability & to a lesser extent fuel economy. The L15 > B16 in those groups.

However its not designed in the least to withstand unholy RPM's & abuse like the B16B.. Yes, they're both N/A 16-valve, I4 engines of similar displacement but that's virtually where it ends.. The B16B's cylinder head flows amazingly well, has a very stout block and an awesome 1.84 rod/stroke ratio & oversqaure bore diameter.. all things you'd have to drop thousands of $$$ on to replicate in an L15; (COMPLETELY reworked head / valvetrain / IM, sleeved block with custom forged & destroked crank, rods + pistons... basically a FULLY built N/A L15 to just match what that late 90's B-Series did on 93 octane)

At that expense, I and most others would think a K-Series swap would be a more fulfilling choice.. shoot, a stock K20A or Z3 would STILL make more hp lol. I think it would be awesome to see; I know of guys that made 160+ whp on pump gas with high compression D-Series engines, but most of them do it just to be unique and know swapping or boost would of got them to those whp levels quite a bit cheaper.

Your views are welcome sir, & you have a nice Miat.. err, I mean MX-5.

 

Before i go to bed...

First of all, I respect your opinion.

I just have a few trains of thought that might make the L15 a motor capable of 180 hp n/a (although i never thought it was possible at first). I believe the main reason the B16B block was so stout is because its max RPM was around 9,200. Now because we have the luxury of a larger stroke, therefore a possibility of more torque in the L15 i think we have a slight advantage. In order to get that much horsepower we don't have to wind the crap out of the engine. I believe if you could somehow harness and work with the power of the larger stroke, you could work it out to making a tuned L15 economy motor, as powerful as a STOCK Type-R, race bread motor.

And what the hell... if all else fails. throw a K20 in there.

 

Sure, no problem ....your 1 liter 100HP ratio is based on RPM

at 1000 RPM it becomes around a 18 HP per liter motor
and at 15K RPM that engine might be a 220 HP per liter motor.

Now your point may be.....100 hp per liter IS a 100 hp per liter, then yes from that standpoint you are correct. Because 100 is max HP for that engine and 1 L is the displacement.

My point is just because car1 makes ___ HP per liter, than car2 ought to make the same.....no because of RPM, and from there you can also guess additionally the lower RPM motor was not designed to breath as well.

My other point is, OK, spin the motor to 8-9K RPM, that gets in theory 180 HP,
but will the head flow? will the injectors supply enough additional fuel? where do I get an ecu with timing and fuel maps at 9K? Longer stroke motors dont like high RPM, will it even hold together?
K swap or FI would be much more cost/time effective way to approach 180 or more HP.

For other than a hand full of guys who go forced induction, 98% of us will be hard pressed and damn lucky to crack 135 HP. (i'd love to be wrong about this mind you)

 

If you don't feel like spending $600+, here's a better alternative and its only $200.





Another "FIRST" in our Industry for Inline Four.

Finally, a successful throttle body solution for Honda's Drive-By-Wire setup!

Calling all Drive-By-Wire equipped 8th Gen Civic's, TSX's, RSX's etc. We can now overbore your factory drive-by-wire equipped throttle body. Over the last month, we have been testing these on various setups in 8th Gen Civics.

The result: Each owner was able to realize an improvement in throttle response, smoother power delivery on accelleration and increased mid-range power. This is a perfect match for those looking to compliment their existing intake and exhaust modifications. We have also had great results when utilizing an overbored throttle body in conjunction with Buddy Club's E-Throttle Booster!

Currently, turn around time for T.B.S. is one business day from the day we receive your throttle body.


Inline Four Drive-By-Wire T.B.S.

What do you guys think? I think I might do it! :3

 

Go for it, but as mentioned I don't think you'll make more than 2 or 3whp without any supporting mods.

 

Trust me I plan to do more than that! :3

 

Still waiting for the KWSC? Lol, well make sure to post some dynos