Honda K24 swap interest?

[Wanganstyle]

Thank you guys this morning for helping me remember I am thankful to live in Texas. Phew. It isn't perfect, and CA is beautiful, but.... What a hassle.

Special cali problems man; its a PITA.

[Bill Brown]

Thank you guys this morning for helping me remember I am thankful to live in Texas. Phew. It isn't perfect, and CA is beautiful, but.... What a hassle.

[Wanganstyle]

Was that a sniffer test on a dyno? If the engine speed is much higher than the factory wanted, that may push more exhaust than the checker wants. It's also likely that tweaking the shift points could tune around that, since the car is an automatic.

twas a long time ago / many cars ago circa 2012; transmission software also has to be smog/bar ok to pass iirc- calfornia smog nazi's ftw :(

With a manual car the smog tech /bar tech will just pick whatever gear they wanna pick so you kinda need the matching ratios to the ECU/engine/etc

[The Dark Side of Will]

I’ve actually failed smog here in California with a stock e36 automatic post final drive change; so yes it does matter

Was that a sniffer test on a dyno? If the engine speed is much higher than the factory wanted, that may push more exhaust than the checker wants. It's also likely that tweaking the shift points could tune around that, since the car is an automatic.

[decay]

I’ve actually failed smog here in California with a stock e36 automatic post final drive change; so yes it does matter

i've gotten a "warning but pass" about final drive from a smog tech who was cool enough to ignore my ITB setup (or didn't recognize it for what it was), but you have to find "that guy".

wangan is right, and you don't even have to go to the ref to get that failure; the regular smog dyno machine you need to sit on every 2 years knows what your speed:RPM should be during the test.

[Wanganstyle]

I did, in fact, but like I said:



Also doubtful that BAR refs are looking at ratios at all... unless someone here has actually had that experience.

I’ve actually failed smog here in California with a stock e36 automatic post final drive change; so yes it does matter

[The Dark Side of Will]

I did, in fact, but like I said:

BMW make (has made) a 188mm ratio every 5% from 2.35 to 4.11, so stuff is out there.

Also doubtful that BAR refs are looking at ratios at all... unless someone here has actually had that experience.

[Wanganstyle]

I thought you knew how to calculate ratios...

3.266/0.738 = 4.43 (Every gearbox in your chart)
4.20/0.81 = 5.19 (420G; BMW already ahead with a wider ratio spread)

3.266*4.389 = 14.33
4.20*3.45 = 14.49

0.738*4.389 = 3.24
0.81*3.91 = 3.17

So something geared like a 420G (which is basically every BMW transmission) with a FD in the range of 3.45 to 3.91 should be great.
The GS6-53BZ even has a 4.02 first, which would be closer to the Honda ratio with a 3.91 final.

Anyway, BMW make (has made) a 188mm ratio every 5% from 2.35 to 4.11, so stuff is out there.

I'd be surprised if the BAR rep was trying to make sure the ratios matched. Last I heard from people in the Fiero community, a swapped car just had to have the same type of transmission (auto or manual) as the donor.

Maybe I wouldn't even be surprised... CA blew through the Poe Limit a long time ago, so now it's impossible to tell whether a given stupid policy is real or someone's parody of how stupid the actual policy is.

To pass the smog dyno; with tiny e30
Size tires requires matching the overall.

Did you consider tire diameter?

[The Dark Side of Will]

This is if you can gear the transmission to
Match

No bmw gearbox has a spread like a Honda k series; both 5/6 speeds share gears and final drive

For example; dc5 rsx base model k20 5 speed; has a double overdrive 4th .921 5th .738; final drive 4.3

Chart from hybrid racing


Will need to do adapt for tire size difference also of the original k series;

I thought you knew how to calculate ratios...

3.266/0.738 = 4.43 (Every gearbox in your chart)
4.20/0.81 = 5.19 (420G; BMW already ahead with a wider ratio spread)

3.266*4.389 = 14.33
4.20*3.45 = 14.49

0.738*4.389 = 3.24
0.81*3.91 = 3.17

So something geared like a 420G (which is basically every BMW transmission) with a FD in the range of 3.45 to 3.91 should be great.
The GS6-53BZ even has a 4.02 first, which would be closer to the Honda ratio with a 3.91 final.

Anyway, BMW make (has made) a 188mm ratio every 5% from 2.35 to 4.11, so stuff is out there.

I'd be surprised if the BAR rep was trying to make sure the ratios matched. Last I heard from people in the Fiero community, a swapped car just had to have the same type of transmission (auto or manual) as the donor.

Maybe I wouldn't even be surprised... CA blew through the Poe Limit a long time ago, so now it's impossible to tell whether a given stupid policy is real or someone's parody of how stupid the actual policy is.

[Wanganstyle]

Honda K24 swap interest?

BMW should have enough final drive selection to make the gear ratios match.

This is if you can gear the transmission to
Match

No bmw gearbox has a spread like a Honda k series; both 5/6 speeds share gears and final drive

For example; dc5 rsx base model k20 5 speed; has a double overdrive 4th .921 5th .738; final drive 4.3

Chart from hybrid racing


Will need to do adapt for tire size difference also of the original k series;

[decay]

BMW should have enough final drive selection to make the gear ratios match.

you might be able to get close enough, but that doesn't solve for that honda never paired a K-series engine with an F-series transmission off the dealer lot

that's what the ref is going to point out

[rover215]

I'll be running the stock G260 5 speed in my swap, with a 3.73 limited slip final drive. The gear ratios are very close to the e30 M3's. I know the engines make power at different rpm's, have different wheel/tire sizes, etc, but it'll be a baseline, I guess. Using KMiata's gearing calculator, I'm happy with the 2977rpm at 70mph.
Looking forward to E30SPDFRK's progress ahead of KMiata's release of oil pan and engine mounts. I don't have those tools or know-how, so I'm playing the waiting game.

[The Dark Side of Will]

BMW should have enough final drive selection to make the gear ratios match.

[decay]

I have a s2k.... manifolds are too different compared to the k stuff to get by bar. Needs to be Oem k series to get by the bar legit

right, or get an EO for whatever part is developed for the kit, and you're probably looking at having to sell 20 kits to recoup the cost of each part... if kmiata decided that wasn't a viable path forward, i would be not at all surprised

also, if i remember correctly, the ref is supposed to care about the transmission, gear ratios, and final drive, also all matching the donor car. if that's the case, a K24 in an E30 "should" never pass the ref, per the rules, because that powertrain was never delivered in that configuration

[Wanganstyle]

Honda K24 swap interest?

Well that's good to know. All you need now is some way to do a CA compliant rwd intake and header. According to speed academy on youtoob s2k headers *sort of* work, might be able to fudge that enough to pass BAR...

I have a s2k.... manifolds are too different compared to the k stuff to get by bar. Needs to be Oem k series to get by the bar legit