What's better than 2 chains moving all the weight of your vehicle? One chain moving all the weight of your vehicle! Conventional wisdom says two is better than one but not when it comes to transmission drive chains. The dual stock chain setup is inherantly weak and uses a staggered gear to engage one link while the link next to it is disengaging. GM says this makes your transmission quieter. The fix is to switch over to a 15/16ths or 7/8ths inch wide single chain setup. These setups are significantly stronger than stock, with both reliably holding over 300whp, much more than the stock chain is capable of.
We're now happy to offer yet another upgrade, this time to the GM 15/16ths inch chain. Available in the same ratios as before, these chains are roller style and from GM's testing are noted to be 12% stronger than the current 7/8ths inch chains*!
We offer our ratio conversion kits in 3 ratios:
What do I get with your kit?
- Machined Driven Sprocket
- Machined Drive Sprocket
- 15/16ths inch Roller Chain
* GM testing - breaking point
What are the advantages/ disadvantages to using the single chain drive? - To understand the advantages of the single chain drive one must first understand the disadvantage to using the stock dual chain drive. The stock setup is designed to function with stock or close to stock horsepower levels but more importantly is designed to operate in a quiet fashion. To achieve this GM has offset the gear teeth by 180 degrees. With this setup one tooth is engaging on the chain while the tooth next to it is disengaging. Much like an exhaust muffler, these two sounds cancel eachother out. The problem is realized when you are making a lot of power and shifting rather hard. The dual chain tends to snap/ stretch under these conditions. The advantage to using the single chain is that it is significantly stronger than the stock setup. The cost is a little bit of an audiable whine down in the low gears. We strongly recommend running the single chain drive over the stock dual chain on cars that are aggresively driven or that are putting down significantly more power than their stock counterparts.
What is the difference between the 7/8th inch and the 15/16ths inch chains? - The two drives use different link setups. The 7/8ths inch chain is 7/8ths inches thick and uses a rocker style chain/ cogs. The 15/16ths inch chain is a roller style and is slightly wider than the 7/8ths unit. The advantage seems to come from the style of chain rather than the nominal increase in width. The other advantage is that on the off chance the 15/16ths inch chain fails it is much more likely to completely snap rather than stretch and damage the case like the other two chains.
How does the PCM react to a gear ratio change - Quite simply it doesn't. This means that your speedometer will lose it's accuracy and the transmission's shift points will be changed. There is a simple way to remedy this problem. The only correct way in our opinion is to reprogram the PCM to compensate for the gear change. This can be done using DHP's PowrTuner software available by clicking here or by purchasing a DHP PCM with a custom tune available by clicking here.
Please Note: 2004+ Grand Prix Comp G's are already equipped with a 3.29 gear ratio
- 1997 - Current Vehicles with 4T65E Transaxle
- 1997 - Current Vehicles with 4T65E-HD Transaxle
|
