[Drsagacity]

It appears Gwatney and Vengeance are similarly priced. What makes the Cunningham setup s much more expensive? Am I missing something?

[Eldi Z]

Originally Posted by Drsagacity

It appears Gwatney and Vengeance are similarly priced. What makes the Cunningham setup s much more expensive? Am I missing something?

Carrillo has always been pricey and considered state of the art quality Rods... Since the merged with CP (Pistons) and most recently acquired Arias (Pistons) as well, they now have a more complete solution for customers:

http://www.cp-carrillo.com/

[parish8]

I think the vengeance is just pistons where the Cunningham is rods and pistons. Then just recently comes the gwatney rods and pistons for a great price.

I don’t know if the Cunningham set up is any better or just first to the market so they were able to charge a little more. It’s not unusual for this type of stuff to get cheaper over time.

[Eldi Z]

Of course the combo as offered by CMS and Gwatney includes the rods as well, which contributes to the higher price overall (compared with Vengence' Pistons only offer), However, Gwatney's offer is a fantastic deal considering you are getting a compete solution, rather than just the pistons.

According to Aaron of Gwatney, a lot of times, rod deformations cannot be visible to the naked eye and only dedicated measurements, I.E. of stock rods in failed engines (that they took apart) reveal these deformations.
So you may think that you can simply drop in forged pistons without replacing the stock rods to stronger ones, when looking at even 650-700 WHP typically, only to find at a later stage, that a failure was caused by the rods bending under stress, or simply due to a tune that may have not been perfect under ALL conditions (and conditions can/do change from the initial dyno tune...).

Another obvious one, but universal and always to be remembered is the proper gap of the rings.
With the modern style cylinder designs / ring materials, having a slightly larger gap is often advised.

[oldman]

Originally Posted by Eldi Z

Of course the combo as offered by CMS and Gwatney includes the rods as well, which contributes to the higher price overall (compared with Vengence' Pistons only offer), However, Gwatney's offer is a fantastic deal considering you are getting a compete solution, rather than just the pistons.

According to Aaron of Gwatney, a lot of times, rod deformations cannot be visible to the naked eye and only dedicated measurements, I.E. of stock rods in failed engines (that they took apart) reveal these deformations.
So you may think that you can simply drop in forged pistons without replacing the stock rods to stronger ones, when looking at even 650-700 WHP typically, only to find at a later stage, that a failure was caused by the rods bending under stress, or simply due to a tune that may have not been perfect under ALL conditions (and conditions can/do change from the initial dyno tune...).

Another obvious one, but universal and always to be remembered is the proper gap of the rings.
With the modern style cylinder designs / ring materials, having a slightly larger gap is often advised.

very good points, considering the stock rod bolts seem to be torque to yield and the arp replacements are like 100 bucks... makes the rods / piston combo just that much smarter deal IMO.

[Drsagacity]

I am checking on price for installation now. The best part is, the rod and piston change won’t require a retune either (if we stay with the same compression ratio. . .although I will have a run on dyno just to confirm.

After this, next click will be to start addressing fuel changes...probably hpfp and injectors followed by in tank pump and a boost-a-pump. Then boost can be increased safely to 650-700rwhp.

Only thing is, my car is breaking the tires loose at 40-50mph as it sits. I guess I should plan on drag radials soon.

[Eldi Z]

Originally Posted by Drsagacity

I am checking on price for installation now. The best part is, the rod and piston change won’t require a retune either (if we stay with the same compression ratio. . .although I will have a run on dyno just to confirm.

After this, next click will be to start addressing fuel changes...probably hpfp and injectors followed by in tank pump and a boost-a-pump. Then boost can be increased safely to 650-700rwhp.

Only thing is, my car is breaking the tires loose at 40-50mph as it sits. I guess I should plan on drag radials soon.

The CMS and GPI Pistons-Rods combos both claim to retain the exact same C/R and weight of the rotating Assy. of the stock motor.

[misterjaayy]

Originally Posted by Eldi Z

The CMS and GPI Pistons-Rods combos both claim to retain the exact same C/R and weight of the rotating Assy. of the stock motor.

CMS drops compression by a point but are the same weight as stock.

[Drsagacity]

Originally Posted by misterjaayy

CMS drops compression by a point but are the same weight as stock.

When we drop compression, we will see boost and power drop. That means we have to run a smaller pulley to make the same power.

If I wanted to go above 750rwhp, I might think differently, but at this time my objective is to make a car that drives like stock and handles like stock until you mash the throttle. A deep 10 second vert that can cruise around with the AC on in heavy traffic. ��

My objective is 650rwhp with the Maggie, forged internals and an upgraded fuel system. I will probably add the cam to finish things off at 750rwhp. That would be good to make the car one of the most wicked verts on the planet.

[parish8]

You would be crazy to get that far into the motor and not do a cam.

[Drsagacity]

Originally Posted by misterjaayy

CMS drops compression by a point but are the same weight as stock.

Originally Posted by parish8

You would be crazy to get that far into the motor and not do a cam.

The cam will require pulling the motor, right? If so, that makes cam my final mod.

Further, I can’t add the cam until I upgrade the fuel system. I like adding the forged stuff first.

[Eldi Z]

Originally Posted by misterjaayy

CMS drops compression by a point but are the same weight as stock.

I thought that the Carrillo-CP combo did not reduce C/R

The Compstar-Diamond combo of GPI does not change the C/R (as far as I understood), so in my opinion the better choice, but then again, for those who are looking at adding boost levels anyway, it would not matter that much that the C/R will be dropped as a consequence, since they are compensating for this (I.E. with a smaller pulley).

[Eldi Z]

Taken from GPI's website:

"...we have worked with Diamond Racing and Callies to offer a no rebalance, standard bore, stock compression, drop-in solution for the Gen V 6.2 liter LT1 engine."

[DFW1LE]

Originally Posted by Drsagacity

The cam will require pulling the motor, right? If so, that makes cam my final mod.

Cam can be done without pulling the engine, but it does take some work.