Turbo Goblin A/T?

[Cmonster]

New member lacking information!
Really interested in getting a side project going and the A/T goblin sounds perfect. I just started looking into this and I'm short on information. Why can't the SS/SC or SS/TC be used with the A/T kit?
I read from Desert Sasqwatch that there is a significant torque loss when increasing wheel size while using the manual transmission. Is it hard or impossible to find a SS/TC w/ a manual transmission?

And finally, can anyone tell me overall length once completed? I'm curious if this will fit in my Toy Hauler.

 

[Desert Sasqwatch]

The A/T was set up by DF to use an automatic trans to help compensate for the torque loss of using larger tires - it allows some slippage that would tend to burn up a clutch. But, it is possible to do a turbo with an automatic, see Torchandregdoc build log. He used a SS/TC HHR automatic and has a list of the nuances to get set up an automatic with the turbo.

BTW, all SS/TC Cobalt came with a manual.

 

[Cmonster]

The A/T was set up by DF to use an automatic trans to help compensate for the torque loss of using larger tires - it allows some slippage that would tend to burn up a clutch. But, it is possible to do a turbo with an automatic, see Torchandregdoc build log. He used a SS/TC HHR automatic and has a list of the nuances to get set up an automatic with the turbo.

BTW, all SS/TC Cobalt came with a manual.

Thanks for the link! I'll take a look at it.

 

[Desert Sasqwatch]

BTW, welcome to the Goblin forum.

 

[Cmonster]

What Are UTV & ATV Portals? Gear Reduction Made Easy

Portals, or portal gear lifts, allow you to lift your vehicle and provide gear reduction to run larger tires, gain torque, and keep your factory steering geometry. Adding a standard lift can cause you to do extensive work to change the gear ratio.

dirtwheelrider.com

Saving some info on the thread. Great write up on ATV Portals to help reduce torque lost with larger tires.

 

[Rauq]

What Are UTV & ATV Portals? Gear Reduction Made Easy

Portals, or portal gear lifts, allow you to lift your vehicle and provide gear reduction to run larger tires, gain torque, and keep your factory steering geometry. Adding a standard lift can cause you to do extensive work to change the gear ratio.

dirtwheelrider.com

Saving some info on the thread. Great write up on ATV Portals to help reduce torque lost with larger tires.

I looked into this as well. Even with a 30% reduction and the super short 4.41 final drive from a Saturn Vue F23, you're looking at 4 mph in 1st gear at 1000 rpms while also turning 2800 rpms at 60 mph with 31" tires. It seems DF's call was accurate- if you want to do anything resembling crawling, you're going to have a hard time with it with a manual trans.

 

[benjy]

Can confirm after loading my manual trans gob onto a trailer last night, I would not want to off road one of these with the factory gearing

 

[Classy]

Big tires on even a 4.08 final drive would be a turd. Do they make final drives for the fwd transmissions?

 

[Ross]

Just mount the engine sideways, and use the stock differential as the center diff in a 4x4. Then add a front and rear differential to the system, which will reduce your speed by 3 or 4 depending on the diffs you use. Nothing a ton of fabricating can't fix

I'm kind of surprised he didn't run tall tires, which would help add some speed back into the car... maybe he liked the extra low gearing.

Hey, he did try bigger tires:

A different ecotec 4x4 buggy.

 

[Cmonster]

Wow - I read through most of Torchandregdoc build log and I'm worried I don't know enough about engines and transmissions to tackle a project modification like this. Points for Forum support! You guys rock and I'm already a fan of DF customer service. More research required.

 

[k.rollin]

You could also just add a turbo to anyof the naturally aspirated automatics versus using an HHR as a donor.

 

[Cmonster]

You could also just add a turbo to anyof the naturally aspirated automatics versus using an HHR as a donor.

This is exactly what I was just researching.

 

[George]

A supercharger would give a better torque curve for the application.

Brad

 

[Cmonster]

I looked into this as well. Even with a 30% reduction and the super short 4.41 final drive from a Saturn Vue F23, you're looking at 4 mph in 1st gear at 1000 rpms while also turning 2800 rpms at 60 mph with 31" tires. It seems DF's call was accurate- if you want to do anything resembling crawling, you're going to have a hard time with it with a manual trans.

I can't translate this into a good mental picture . What would the effect be if just off road on trails and mud? Not rock crawling just chasing a Polaris through an ATV trail. Would the loss of torque be that noticeable? We would not be using this strictly off road so best of both worlds with a performance dip on bigger tires might be fine for us.

 

[Desert Sasqwatch]

A turbo automatic on trails and open terrain would be really good. Rock crawling not so much. The HHR SS install that Torchandregdoc did worked out great, so it is highly doable and DR has the info now to use a HHR as a donor.

 

[Rauq]

I can't translate this into a good mental picture . What would the effect be if just off road on trails and mud? Not rock crawling just chasing a Polaris through an ATV trail. Would the loss of torque be that noticeable? We would not be using this strictly off road so best of both worlds with a performance dip on bigger tires might be fine for us.

Maybe this adds to the perspective.

Application	Final Drive
Base Cobalt (non-XFE)	3.84
Cobalt SS/SC	4.05
Saturn Vue	4.41
Saturn Vue + theoretical 30% underdrive portal hubs	6.3

1000 RPM entries are in 1st gear, 60 mph entries are in 5th gear

	RPM	Speed
3.84	1000	7
3.84	1699	60
4.05	1000	7
4.05	1844	60
4.41	1000	6
4.41	1951	60
6.3	1000	4
6.3	2787	60

60 mph rpms are given for some on-road driveability perspective. The relevant part for offroading is that under these speeds (4-7 mph) you're probably going to have to be riding the clutch, and you're only going to be making like a fraction of peak power. It's going to be hard starting on an incline without absuing the clutch or spinning the tires. In comparison, an auto has no issues idling along and you can get a bit more power with some throttle as the torque converter allows the engine to flash a bit higher.

 

[Cmonster]

Maybe this adds to the perspective.

Application	Final Drive
Base Cobalt (non-XFE)	3.84
Cobalt SS/SC	4.05
Saturn Vue	4.41
Saturn Vue + theoretical 30% underdrive portal hubs	6.3

1000 RPM entries are in 1st gear, 60 mph entries are in 5th gear

	RPM	Speed
3.84	1000	7
3.84	1699	60
4.05	1000	7
4.05	1844	60
4.41	1000	6
4.41	1951	60
6.3	1000	4
6.3	2787	60

60 mph rpms are given for some on-road driveability perspective. The relevant part for offroading is that under these speeds (4-7 mph) you're probably going to have to be riding the clutch, and you're only going to be making like a fraction of peak power. It's going to be hard starting on an incline without absuing the clutch or spinning the tires. In comparison, an auto has no issues idling along and you can get a bit more power with some throttle as the torque converter allows the engine to flash a bit higher.

That clicked! Thank you for breaking it down.

 

[Cmonster]

Ok. Plan is to try the HHR SS on the A/T kit. Gotta run budget timeline through the boss and start looking for a donor.

 

[Ark :D]

Here you go.

https://www.copart.com/lot/49451400/salvage-2008-chevrolet-hhr-ss-oh-cleveland-east

 

[Rauq]

Manual control of the auto trans has been done before if a prndl (pronounced "purrn-dull") is still a significant hangup for you: jpr's shifting setup