Changing Gears

[rgnbull1227]

Im changing the gears on my Superformance from 3.45 to 4.10. What are ALL of the parts needed for this?
Thanks.

[STL Mark]

Not sure what differential you have. Others here would know. If you have the BorgWarner (2005 GTO) version, like I do (3:46) on SPF2693 - the ring and pinion is available in 3:70 & 3:90 versions.

[rgnbull1227]

Hmm. I was told it was the ZF 8.8 rear.

Actually just checked with SPF and they said they think I have a 3.46 diff ratio. Would that be the borg warner?

[Wbulk]

I would not do it. 3.73 is about as far as I would go with your SB. A lot of guys regret going to 4.10s. Do the math first.

[blykins]

Never a regret with 4.10-4.30 gears, especially with the higher strung engines and a 5 speed. Perfect combo.

[mdross1]

The 5 speeds made changing gears a little easier.Our big block car has 3:73 for me an excellent combo.Agree with blykins on the high stung sb,remember the Z-28 Camaro's and Boss 302 Mustangs.

[Mark IV]

Originally Posted by rgnbull1227

Hmm. I was told it was the ZF 8.8 rear.

Actually just checked with SPF and they said they think I have a 3.46 diff ratio. Would that be the borg warner?

Your car has the Dana "GTO" diff, the ZFs start in the higher 2900s. You have a 3.46 ratio. You can install any gearset that fits the HydraTrak diff, some are available via GM and there may be some aftermarket. Do a little Googling and you wil get some info.

The "8.8" is the early Ford(T-Bird) diff used until they switched to the Dana

[bulletbrown]

If you have a GM GTO , which is the same as the new Camaro, I would up grade the unit to stand up to that much power. It is a wonder you have not blown it aready. It is not a strong unit to begin with . I sell Camaros and we have repair a number of this unit on stock Camaro,s . We sell Camaro to Nickey custom Camaro builders and then change half shafts ect. in the hopes they will hold up to the added power of the supercharges they install. If you put a low gear ratio and sticky tires you will blow it to pieces . There is venders that will sell you the badly need up grades.

[rgnbull1227]

This is the rear installed from Superformance so I assume its the proper rear for the car. I think I will throw this on a lift Monday get the numbers off the rear.

[STL Mark]

Originally Posted by bulletbrown

If you have a GM GTO , which is the same as the new Camaro, I would up grade the unit to stand up to that much power. It is a wonder you have not blown it aready. It is not a strong unit to begin with . I sell Camaros and we have repair a number of this unit on stock Camaro,s . We sell Camaro to Nickey custom Camaro builders and then change half shafts ect. in the hopes they will hold up to the added power of the supercharges they install. If you put a low gear ratio and sticky tires you will blow it to pieces . There is venders that will sell you the badly need up grades.

No worries. I run Goodyear Eagle GT IIs. Basically the tires don't stick. So, I'm never in danger of destroying the rear end or the axles. If I needed a rear end that would hold up to full-on drag passes, I would pull the whole mess out and re-build with a much more substantial system. But, I have managed an 11.3 pass on those street tires. As it is, the 3.46 is a good road racing platform for now. On the track, even with Hoosiers - the stock SPF (Dana/GTO/whatever) does fine.

[JBCOBRA]

What transmission do you have in your car now?
Do you know what your first gear ratio is?
For example: If you have have a Tremec 500 and a 4.10 rear. First gear will be totally useless.
Just saying.

[rgnbull1227]

I do have a tremec t-500. Also, after being concerned about the strength of the rear as a result of a post above i reached out to SPF for clarification. Here was the response....
" It is the Dana and is the preferred Rear end to many SPF owners. It is very strong and you also have to take into consideration the weight of the car. There are literally a thousand cars with Big Blocks and much more torque running around with those rear ends in them. There are also over a thousand Windsor based with 427 /500HP/500ft.lbs. TQ still running around with no issue. We would still be using them if they were still available. I’m surprised that the guy would even say that if he really knew what he was talking about. Those rear ends are really bullet proof in this application. I suppose that if you put slicks on the car and Drag launched it a few hundred times you may hurt something but that would apply to almost anything out there. "
Just in case anyone was wondering.

[mpanten]

Originally Posted by Wbulk

I would not do it. 3.73 is about as far as I would go with your SB. A lot of guys regret going to 4.10s. Do the math first.

If he doesnt like them I will switch my 3.73's for his. With a 5spd overdrive 4.10's should be no problem.

[rgnbull1227]

Originally Posted by mpanten

If he doesnt like them I will switch my 3.73's for his. With a 5spd overdrive 4.10's should be no problem.

My plan as of now is 4.10 with a .82 OD.

[mpanten]

Originally Posted by rgnbull1227

My plan as of now is 4.10 with a .82 OD.

I have a .62 OD with a 3.73. I was worried about going higher and loosing highway driveability. No problems at all. wish I would have went with 4.10.

[rgnbull1227]

Looks like this will be the final outcome.....

[JBCOBRA]

....so you may as well start off in second gear.
With the TKO 500 first gear is almost useless with 3.73 rear gears

[mpanten]

Originally Posted by JBCOBRA

....so you may as well start off in second gear.
With the TKO 500 first gear is almost useless with 3.73 rear gears

40 Mph with 4.10's at 6500 seems good to me. How is over 40mph in 1st useless?

[rgnbull1227]

Im trying to figure out the same thing. These numbers seem fine to me.

[itstock]

Traction.