Custom gear ratios in 1.8 MT

[coryolis175]

Has anyone dropped any custom gear kits in their 5-speed 1.8 Sonic? I am building a rally car out of mine. Had my first race, and realized I'm basically driving in 2nd and 3rd the whole time besides some really tight corners I dropped into 1st. I'd like to upgrade to some close ratio gearing to utilize the 5-speed, and not be running a 3-speed tranny on race day. I've looked into some foreign websites like Quaife and see some things available for the F-13 and F-15 boxes. Pardon my not being a gearhead at all, but I don't know what's compatible with what. Is there anybody out there that has done custom work on the F-17, or have any insight here?

And being brand new to this site, I have attached a pic of my car so you guys can get a vague idea of what I've been working on. Also, HELLO!

Thanks!

 

[Natesriv]

slightly related... but on Wheeler Dealers they modded an old Ford and put in straight cut gearing...holds up better (louder)...

But your idea sounds good, but to keep up the pace you have to be at a certain RPM (which puts you in the engine's power band).. so if you lower your upper gear ratios, won't you just be still at that RPM?

I'm no transmission gearhead myself!

 

[nickalltogether]

slightly related... but on Wheeler Dealers they modded an old Ford and put in straight cut gearing...holds up better (louder)...

But your idea sounds good, but to keep up the pace you have to be at a certain RPM (which puts you in the engine's power band).. so if you lower your upper gear ratios, won't you just be still at that RPM?

I'm no transmission gearhead myself!

Straight cut are stronger because they don't put axial load on the gear shaft like a helical gear set would. At 1.8 N/A power level this probably won't be a problem. Fun fact- many manual cars (Honda comes to mind) have a straight cut reverse gear, and that's why you hear the wurwurwurwur when they back up.

Regarding your second question: he would probably want a gear set that are closer together, gear ratio wise, and I imagine a lower (higher numerically) overall final drive. That way he stays in his powerband better for his range of speed in rally.

Sport bikes use similar gearing strategy because they are race-bred. They are 6 speed but the gear spread is very close. My ZX-10R could do 100mph (indicated) in 1st gear but 6th gear was only geared for upper 180s (indicated). This meant that once you got in the power band you never dropped out of it. Compared to my Sonic where 1st can go to 25mph and 6th is geared for (not nearly enough power obviously) something like 180mph.

To OP: You may consider talking to Liberty Gear. They could potentially offer their opinion. I doubt you'll find anything off the shelf unfortunately.

 

[Stew]

Is using an RS transmission an option? Those are geared the shortest of all I believe and would seem like it'd be less expensive finding one of those than custom gears.

 

[carsNskis]

The RS trans is an M32-6 globally, here's a great link for info https://tech2.guru/vauxhall-m32-6-speed-manual-transmission/

Seeing as it's been used in a variety of GM motors from 1.4 up to 2.0 there's no reason to think it wouldn't bolt up. I can't confirm if there's a change to the input shaft or not.

The next upgrade would be the Aisin F40 (found in the Cruze, etc) https://en.m.wikipedia.org/wiki/GM_F40_transmission

I think the RS gearing would be better suited to rally, but the F40 will take more punishment (you can bolt up a little V8 to that sucker!! but the RS torque max is 320 nm, thus m32 btw)

 

[$ub$onic]

Had the same issue with my 1.8 sonic racecar, started running a small diameter wheel and it helps a ton BUT that more then likely will not work for you


If you can trans swap, check into a m32 6 speed, lots of gear options



Also. What are you running for a suspension?????

Sent from my S60 using Tapatalk

 

[carsNskis]

Had the same issue with my 1.8 sonic racecar, started running a small diameter wheel and it helps a ton BUT that more then likely will not work for you


If you can trans swap, check into a m32 6 speed, lots of gear options



Also. What are you running for a suspension?????

Sent from my S60 using Tapatalk

Inquiring minds want to know, that thing has some travel!

 

[coryolis175]

Hey all,

Thanks for the responses and open discussion!

I looked up the 6-speed Sonic transmission, and looks like the one that's geared down the most has a 4.176 final drive and gear ratios from 4.27 to 0.74. I plugged this into my handy-dandy spreadsheet, and that looks like redline speeds of 25, 45, 72, 99, 121, 144. This is MUCH better than the stock setup I am running now, but still would probably never use fifth or sixth gears. Most of my racing speeds were between 30-70 mph. I've only done one event so far, so I'll need more wheel time to get a real confident range.

I REALLY like the idea of bolt-on compatibility. As someone who doesn't know what works and what doesn't, that is music to my ears as a possible option. Definitely something I will explore further. Could be something down that alley for me.

To nickalltogether, I clicked on your link and it brought me to eBay, showing metal gear solid playstation games and liberty camo hunting gear. I'll have to google search to see the real company you're talking about.

For those asking about the suspension. I'm running Sooper Bitchin Suspenders, from JVAB in Seattle. Bilstein components with custom mounting.

 

[nickalltogether]

Hey all,

Thanks for the responses and open discussion!

I looked up the 6-speed Sonic transmission, and looks like the one that's geared down the most has a 4.176 final drive and gear ratios from 4.27 to 0.74. I plugged this into my handy-dandy spreadsheet, and that looks like redline speeds of 25, 45, 72, 99, 121, 144. This is MUCH better than the stock setup I am running now, but still would probably never use fifth or sixth gears. Most of my racing speeds were between 30-70 mph. I've only done one event so far, so I'll need more wheel time to get a real confident range.

I REALLY like the idea of bolt-on compatibility. As someone who doesn't know what works and what doesn't, that is music to my ears as a possible option. Definitely something I will explore further. Could be something down that alley for me.

To nickalltogether, I clicked on your link and it brought me to eBay, showing metal gear solid playstation games and liberty camo hunting gear. I'll have to google search to see the real company you're talking about.

For those asking about the suspension. I'm running Sooper Bitchin Suspenders, from JVAB in Seattle. Bilstein components with custom mounting.

I didnt provide any link - it may have been an ad from the site. Metal Gear Solid is a good game though...

 

[$ub$onic]

You will never be able to use all the gears. 5th in the 5 speed and 5/6 in the 6 speed are mainly highway gears.

If you can even utilize 4th in the 5 speed that's doing good, I've only been able to do it a hand full of times


The m32 mzO is the oem trans for the 1.8 Cruze

Sent from my S60 using Tapatalk

 

[$ub$onic]

Also, can you make a thread on your suspension? I'd like to see pictures!

Sent from my S60 using Tapatalk

 

[Palmaris]

Hey all,


For those asking about the suspension. I'm running Sooper Bitchin Suspenders, from JVAB in Seattle. Bilstein components with custom mounting.

AHHH, JVAB. You sound just like him already!

 

[Palmaris]

I didnt provide any link - it may have been an ad from the site. Metal Gear Solid is a good game though...

Yes, the site is known to add links to your text if you have any key words. Best to ignore them.

 

[coryolis175]

I don't cuss nearly eloquently enough to sound like Vanlandingham. I try, but I'm not there yet. My Yooper/Finnish blood gives me a chance to be there someday though!

Does anyone know if the F15 transmission is interchangeable with the F17? Many places list parts available for F13/F15/F17, making it seem like they're all pretty much the same thing. Any truth to this? There is a close-ratio gear kit for the F15 made by Quaife that I drool over. Pricey to buy new, but gives me hope that a used one might be available somewhere out there in this world...

And I will start a thread in the suspension room with some pics I snapped of my setup.

 

[coryolis175]

Did anyone get that aftermarket, lighter weight flywheel that (I think) was on BNR like a year or two ago? It was an upgrade that I had planned on installing, but now I can't seem to find it.