I can do 45mph in first gear and it will downshift into first gear which is something I've had an issue with other automatics.

I think the 2.77 gear ratio would be the only way to go and have a useful 1st gear. The 2.77 final drive has a nice cruising speed of 70 MPH at 2000 RPM (and crazy theoretical top speed). The tall gearing of the 2.77 would also offset the 4.48 first gear. Here are a few analysis screen shots to help explain and visualize.

2.77 final drive:







3.16 final drive:







3.39 final drive:

I agree that the 2.77 final drive would be nice, but it is only available in the 6T70, not the 6T75.

The transmission cases are different enough that you can't just swap them. We have a 6T70 and another 6T75 to see if we can build a beefed up 6T70 with the 2.77 final drive using as many interchangable parts from the 6T75. It is on the to-do list, but I am not sure when that will happen. Right now we are just focused on putting miles on the 6T75 that is in the car.

Those are some very nice graphs! Great software.

I currently cruise at 70 MPH under 2000 RPM (LS4 + 4T65E-HD).

Would it be possible for you to perform some simulations for my vehicle?

255/45-18 using the same or similar constraints (2.77 and 3.16 only please).

Sure... Its free software from performance trends from '98 (trial). Not sure if its still out there or not???

2.77:






3.16:

Thank you for those!

Dan did you get my message?

I know the starter has been sorted out, but it seems like that pocket was indeed specifically made for a starter.

This was brought up before by a member on another forum and maybe this is where Dan86GT got the idea from.

Ford 6F50:













Any controller updates? Harness pictures?

quote Originally posted by Dan86GT: Can the I agree that the 2.77 final drive would be nice, but it is only available in the 6T70, not the 6T75.

Could the Ford 6F55 final drive be swapped into the 6T75??? The final drive ratios available with GM's 6T75 were in SUVs with large diamater tires. The MKS (and Taurus) with the ecoboost has the 2.77 final drive meant to be used with a smaller diameter tire (25.9") that is more in par with the Fiero.

http://www.scribd.com/doc/1...-new-EcoBoost-engine

"The clutches on the 6F-55 transmission feature high-energy friction materials that can handle higher loads and shift energies over the long term, so customers will experience smoother shifts.The ring gear on the 6F-55 is increased to 41.5 mm compared with 31.5 mm on the 6F-50 to handle the increased torque of the EcoBoost Engine. The final drive ratios of 2.77:1 in the Lincoln MKS and 3.16:1 in the Lincoln MKT were chosen for optimum performance and fuel economy and confidently deliver improved responsiveness."

[This message has been edited by Lonster (edited 05-06-2013).]

That'd be great if that 6F55 stuff (2.77) could be swapped in.

Any updates Dan?

EDIT: Corrected some information.

[This message has been edited by GXP25 (edited 06-25-2013).]

Officially made the Construction Zone!!

Everything is going great with the car. Just shy of 1000 miles since the swap and absolutely no issues. Averaging 20 mpg and driving fairly hard.

My email notifications broke when the thread moved so hopefully that will be fixed now. Will post more updates soon.

Dan

This is what first gear is like. This is from a slow rolling start.... it goes on the rev limiter almost instantly until you lift....

quote Originally posted by Dan86GT: This is what first gear is like. This is from a slow rolling start.... it goes on the rev limiter almost instantly until you lift....

Sounds like you have the rev limiter set at about 3K.

You almost hear the limiter before you hear the tires & before you see the rubber trail.

Archie

It's hard to tell from the video how fast the tires are spinning before you hear them and see marks. The rev limiter is stock for the LS2.

I knew first gear would be something else, but damn.

Any idea if some of the Ford version pieces could be swapped over?

Not sure about the Ford swap. I would guess the 6F50 is interchangable with the 6T70 and the 6F55 with the 6T75. Does the 6F55 come with a 2.77?

The 6F55 in the SHO comes standard with 2.77.

The 2013 [optional] SHO Performance Package gets the 3.16:1 ratio.

EDIT: http://media.ford.com/image...Taurus_SHO_Specs.pdf

[This message has been edited by GXP25 (edited 06-25-2013).]

Any updates?

When will the controller be available?

Everything is still running great. Thought I would have a 1/4 mile video to post but I got rained out.... Probably a good thing since I had the radiator cap blow off during a wide open blast shortly after the drag strip rainout. Coolant went over the windshield and it took 2 gallons to top it off. The radiator cap was captured in the headlight bucket. Do I need to wire tie it? Anyone have that happen before? Not sure if it was slowly working its way off or happened all at once.

Hope to have a drag strip or dyno video to post soon.

Over 2000 miles and running strong.

Dan

[This message has been edited by Dan86GT (edited 09-06-2013).]

quote Originally posted by Dan86GT: Everything is still running great. Thought I would have a 1/4 mile video to post but I got rained out.... Probably a good thing since I had the radiator cap blow off during a wide open blast shortly after the drag strip rainout. Coolant went over the windshield and it took 2 gallons to top it off. The radiator cap was captured in the headlight bucket. Do I need to wire tie it? Anyone have that happen before? Not sure if it was slowly working its way off or happened all at once. Hope to have a drag strip or Dino video to post soon. Over 2000 miles and running strong. Dan

I have never had a problem with the cap working loose. It is hard to get to and maybe was not secured all the way? Usually the problem with the cap is that the part number in the parts stores books are wrong and they leak pressure.

What pressure cap do people with LS motors run?

[This message has been edited by Dan86GT (edited 09-06-2013).]

quote Originally posted by Dan86GT: What pressure cap do people with LS motors run?

I have 3 (three) caps in my swap. BUT only one of them actually works. The front cap on the radiator is 20# and I capped off the "overflow" hose barb so it can not vent air back into the system as it cools. The stock LS4 has a radiator cap on the water pump and I modified it so it does not function as a radiator cap. The one cap (out of the three) that works is on the surge tank. It is the only functional cap because it is the highest location in the cooling system. Theoretically only "air" purges out of it. That surge tank radiator cap is a 16# cap.

quote Originally posted by Dan86GT: What pressure cap do people with LS motors run?

My LS4 swap has the stock LS4 coolant fill cap, but the housing had the vent welded shut - so it no longer vents. The only other cap in my system is a 16 lb radiator cap that has the stock vent tube hooked up to the stock fiero overflow tank. I did have an issue with the passenger head light snagging on the vent hose, but I was able to wire tie it out of the way. Have you check the clearance between the radiator cap and the passenger head light to see if it could be tapping the cap as it opens/closes and backing it off gradually?

Nice update.

Any idea when the controller will be available for purchase?

Found this interesting article while looking for info on this trans. Long story short, you could overheat the trans if you overfill it.

Hopefully we see an update soon, would love to see a drag vid with silicks!

6T75 overheat

Here's some interesting information on the XTS Vsport's transmission: the 6T80

quote Completing the drivetrain for the XTS mounting was a specific challenge. There was no transverse equivalent to the high-torque-capacity 8-speed used with the new rear-drive CTS Vsport or even a transmission equivalent to the 6L90 6-speed coupled to the CTS V8. Instead, GM's highest-capacity front-drive transaxle available, the 6T75, was beefed up internally for increased torque and higher duty cycle. It now carries a 6T80 designation and features a stiffer case to better hold gear alignment. The shift cable mounting was redesigned and the torque converter was upgraded, and there is a new converter housing mounting interface specific for the twin-turbo engine. Bill Peterson, lead development engineer for the XTS Vsport, said with the internal modifications the 6T80 can handle the direct-injection twin-turbo V6, SAE rated at 410 hp/369 lb·ft (306 kW/500 N·m) throughput. This compares with the twin-turbo used in the CTS Vsport that is SAE rated at 420 hp/430 lb·ft (313 kW/583 N·m). By comparison, the XTS's base 3.6-L V6 produces 305 hp (337 kW) and 265 lb·ft (355 N·m) and is paired with the 6T70. The XTS Vsport has an all-wheel-drive system, an Audi-like configuration that is designed to mitigate the torque steer associated with a front-drive. It is used with an all-mechanical Haldex AWD coupling for front-rear torque distribution into an electronically controlled limited-slip rear differential. There is no defined torque split in this system. It is physically capable of transferring up to 1000 N·m (736 lb·ft) of propshaft torque to the rear, which is double the engine's maximum torque output. On a normal launch (all wheels on dry pavement), the front-rear percentage split is about 50-50. Under dynamic conditions, the transfer is based on inputs from vehicle sensors to maximize driving control.

More info here: http://articles.sae.org/12435/

Any updates Dan?

How is the transmission holding up?
Any fuel economy numbers?

Still watching

-Mitch

Yeah, some kind of update would be greatly appreciated!

[This message has been edited by GXP25 (edited 04-14-2014).]

No news is good news....

The car is still running great. Winter finally ended (I think) and have been driving the car for a week now.

Nothing exciting to report. Transmission is running flawlessly. Going to focus on the suspension for now. I have a set of coil overs on it that are either shot or just not designed right for the job.

Anyone have any suspension suggestions?

Dan

Did you make it to the strip yet?

QA1's are popular and nicely adjustable but not cheap.

Go with the Koni coil over for the rear. Adjustable struts w/ the ability to tune the ride height, and rebound pressure. $800-900 at Aurart Motorsports.

Rob

quote Originally posted by tampalinc: How is the transmission holding up? Any fuel economy numbers?

No fuel economy numbers yet... I really don't drive it for economy. I can see the fuel gauge moving when I drive it. I would guess fuel economy would be slightly better than an LS2 corvette. Ironically when I am not driving the fiero I drive a VW TDI which averages 45 mpg...

Dan

What bushings and such do you have in your cradle and suspension?

Interested in a spherical bearing conversion?

Also, ditto on recommendation for Konis. I've gotten both of my sets at www.shox.com

[This message has been edited by Will (edited 04-23-2014).]

Thanks for the update Dan.

Any news/word on the controller and adapter plate?

quote Originally posted by Will: What bushings and such do you have in your cradle and suspension? Interested in a spherical bearing conversion? Also, ditto on recommendation for Konis. I've gotten both of my sets at www.shox.com

Hmm... Tell me more about the spherical bearing conversion. I did a forum search but didn't find anything.

I have stock rubber in the cradle, engine is hard mounted to the cradle. Suspension uses poly.

Are the konis true coilovers or konis for the fiero with the DIY coilovers conversion a lot of people seem to do?

Dan

Koni doesn't make coil overs for the Fiero. You have to DIY or buy some from a shop like West Coast FIero.

Stock cradle rubber can do weird things. Get rid of it... got with aluminum (prefered) or poly.

I'm working on weld-in sleeves to convert Fiero control arms to spherical bearings. They aren't any harsher than urethane (per guys who have run other cars with spherical bearings: http://www.corner-carvers.c...owthread.php?t=47287 ) and provide less binding/friction, better maintainability and greater handling precision.
I've done the design work to make the sleeves compatible with the control arms.
I'm having trouble finding a good sealed spherical bearing that will last a long time.

quote [B]Originally posted by Will:[/ Stock cradle rubber can do weird things. Get rid of it... got with aluminum (prefered) or poly.

The engine is hard mounted. I figured I needed something between the engine in the chassis. Do most people hard mount the engine and the cradle? Seems like that would be rough.

Dan

The best way to do it is solid mount the cradle to the body, then soft mount the powertrain to the cradle.

Soft mounting the engine may be a pain at this point. Maybe I will keep the hard mounts but switch the cradle to poly.

Does anyone have target corner weights for the fiero? Need to figure out my ride height and suspension issues.

Dan