Honda Insight w/Acura TSX engine - Ecomodding

[redpoint5]

Originally Posted by Ecky

Definitely planning on a custom 3.4 FD, even if it's $$$$. Even with that crazy tall gearing, it's still going to be geared shorter than the stock 1.0L.

Love my 2006 TSX. The only thing that could be improved on the car is taller gearing, better sound proofing, and a tighter turning radius (turns worse than a bus). Oh, and VTEC should activate sooner than 6k RPM. When shifting at the redline around 7k, the revs fall below VTEC activation so the engine is sluggish again until building back up to 6k. It should have been designed to activate at 5k.

How hard would it be to change out the FD? Would love to get the revs down. 1st gear is so low that I can't imagine the car being difficult or sluggish to drive with a taller FD. Too much torque off the line anyhow.

[Ecky]

Transmission needs to be drained and removed, of course.

I'll see if I can find any good how-to's later. It would be very helpful to me if someone went in on a group buy for some taller final drives. 3.4 might be too tall for you though; you'd probably be sub-2000rpm with your stock tire size at 65mph in top gear... or maybe that's a good thing? You'd practically have a "2 through 7" trans rather than 1-6.

EDIT: A custom super tall FD (3.4) requires a group buy and is probably going to come out to $1200. A slightly taller FD (4.108) is available here for $450. Of course, it's not as taller.

https://www.afhparts.com/oem-parts/h...=41233-RAP-000
https://www.afhparts.com/oem-parts/h...=23221-RAP-000
Source

[Ecky]

Trying to decide.

3.4 FD, stock 165/65r14 tire size
2180rpm @ 65mph
1680rpm @ 50mph

3.4 FD, common 185/65r14 tire size
2085rpm @ 65mph
1605rpm @ 50mph

4.105 FD, stock tire size
2635rpm @ 65mph
2025rpm @ 50mph

4.105 FD, 185 tire size
2520rpm @ 65mph
1949rpm @ 50mph


Honda Insight 1.0L gearing - 3.208 final drive
2350rpm @ 65mph
1810rpm @ 50mph


I really think a 3.4 FD is a good idea, but it adds considerable cost to the build. I suppose the 4.105 wouldn't be the end of the world if I moved to a larger diameter tire too.

[vskid3]

Why not put the engine in the back? Welcome to Mini Tec

I support this build. While Insight's stock drivetrains won't last forever, their bodies will, so why not have fun with all that lightness?

[redpoint5]

Originally Posted by Ecky

EDIT: A custom super tall FD (3.4) requires a group buy and is probably going to come out to $1200. A slightly taller FD (4.108) is available here for $450. Of course, it's not as taller.

I know the RSX has a taller FD, and was hoping there might be used parts for relatively cheap. I'm not willing to drop more than about $200 on the mod. 3.4 sounds too tall though, as I wouldn't want to start from a dead stop in 2nd gear. Something around 4.0 seems ideal for me.

[Ecky]

Send an email to Jeff Owen, at kiwi@specialprojectsms.com. He has some relatively inexpensive ~4.0 final drives. I may do the same.

[Ecky]

Originally Posted by redpoint5

I know the RSX has a taller FD, and was hoping there might be used parts for relatively cheap. I'm not willing to drop more than about $200 on the mod. 3.4 sounds too tall though, as I wouldn't want to start from a dead stop in 2nd gear. Something around 4.0 seems ideal for me.

While I'm thinking about it, it's very common for people with a 4.389 FD to want to swap out for a 4.7 or shorter. You can probably find oodles of 4.3's for next to nothing on forums and eBay. Definitely less than a new 4.0, and still good for an 8% reduction in RPM.

Fun fact: TSX gearbox WITH a custom 4.059 final drive has similar gearing in 6th gear to the Insight's 4th gear. TSX 4th gear is equal to the Insight's SECOND gear.

[samwichse]

I think of all the choices, I'd most want the L15...

Maybe you could hack up the stock intake to not be so tall?

Seems like that way would get you the best combo of gas mileage and fun...

[Ecky]

Originally Posted by samwichse

I think of all the choices, I'd most want the L15...

Maybe you could hack up the stock intake to not be so tall?

Seems like that way would get you the best combo of gas mileage and fun...

Unfortunately:

Deck height:
R18A/R20 - 230mm
K20 - 212mm
K24 - 231.5mm
B16A - 203.9mm
B18/B20 - 212mm
L15A - 220mm

So the L15A is between a K20 and K24 in deck height. Not a deal breaker in and of itself, but it sits vertically rather than tilted back like the K series, because the Fit's engine bay is tall but not very deep. I bet it could be made to work, but when you combine the lack of any aftermarket intakes, that the intake is plastic and thus can't be cut and welded, that there are no aftermarket gears (though the Insight and Civic Hybrid's final drives most likely fit), and that the mounts must also be fabricated, whereas Hasport has off-the-shelf mounts coming out for K motors, it's a tough sell for me. All else being equal, I'd take an L15B any day of the week.

[samwichse]

According to this: a CRZ manifold is a bolt up:
https://www.crzforum.com/forum/do-yo...d-30-mins.html


https://ahparts.com/buy-used/2011-Ho...RTW000/84576-1


Maybe that would be a bit more doable?