Converter differences X & G

N2BRK

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Dec 31, 2009
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My truck is going under the knife this week and I chose a local builder with a great rep; I'm stoked! I've asked a couple people here about converter advice, and I have opinions that I really appreciate and value! Since Friday is my day to decide, I'd just like to gather as much info on the differences between two converters as possible, to decide where my wants/needs fit best.

Truck:
2002 Lb7 CC/SB 4x4. On order - typical stock/S475 cast wheel compound kit. Fuel will be stock injectors for now but a larger cp3. At some point injectors will be larger, but they were just installed before I bought the truck and I'd hate to yank them yet. I DD this truck every day and the only towing that I do regularly is my 7x16 enclosed with dirtbikes and gear etc :) I only tow heavy on rare occasion a couple times/year and it's flat as a pancake where I live. I'm at sea level. I DO romp on it plenty though; boosted launches and powersliding a fair bit :devilish:

The field has been narrowed down to a Goerend X or G. I'm sure that I can't go wrong either way, but I have no ownership experience with an Lb7 until now and never did compounds; I had Mark's awesome 68mm stg2r in my LMM for the past decade :)

Thanks in advance!
Wally
 

PureHybrid

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The G is great for towing, never driven one though. If you're towing light most of the time and want to hot rod it a little but are afraid to move to the R, maybe the DK? I drove a customer's truck (LB7) with a DK and it seemed great.
 
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Bdsankey

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Personally I really really love the R. It works great in just about anything. The DK and DL are great as well.

For my driving style I prefer them over the G or X although they are great converters.
 
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darkness

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I vote for the R as well. I wish I had a higher stall in my ‘04 but the trans wasn’t built for compounds at the time. You’re going to want to get on top of that non vgt turbo as soon as possible and the higher stall will help.
 

malibu795

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With a Stock small charger . This is what's going on mine.. basically a built version of the transtar/remax AX7L.

But I'm kinda the outlier exception to the generalization
Side note..
You will need part throttle shift points adjusted do to the substantially better coupling the TC has
 
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N2BRK

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1600 stall. Wow. Any tighter and I’d marry it.

I was set on the G, since I’m stock valley and 475. Trans builder wants to put in an X. I haven’t talked it over with him yet though. Many people have said R. I know in my old setup I couldn’t get the R out fast enough; hated it. But I have to wring out the sponge of what I know from 15yrs with the LMM and absorb lb7 knowledge! 😊
 

malibu795

misspeelleerr
Apr 28, 2007
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1600 stall. Wow. Any tighter and I’d marry it.

I was set on the G, since I’m stock valley and 475. Trans builder wants to put in an X. I haven’t talked it over with him yet though. Many people have said R. I know in my old setup I couldn’t get the R out fast enough; hated it. But I have to wring out the sponge of what I know from 15yrs with the LMM and absorb lb7 knowledge! 😊
It's Definitely nice, plus all the added mid-range TQ you'll have with the twins will make it really nice.

People seam to forget, the 5/6sp Allisons have a 3.10:1 first gear.

G seams pretty close to stock.. IMO stock is too loose.
 
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N2BRK

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That may be why the X was recommended.

Without direct experience it’s hard to decide when recommendations vary from x to r! That’s a massive spread.

Marks tuning and converter in my LMM blew through everything :) The 1077 was my favorite converter in that truck. But that’s a whole different ball of wax.
 

Bdsankey

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With a Stock small charger . This is what's going on mine.. basically a built version of the transtar/remax AX7L.

But I'm kinda the outlier exception to the generalization
Side note..
You will need part throttle shift points adjusted do to the substantially better coupling the TC has
Keep in mind DPC converters do tend to run 10-15f warmer due to their design. Not a bad thing just they run warm which is why we don't use their single disk in our OEM+/550whp builds.
 
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JoshH

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The X is a very hard coupling converter that helps bring in the torque on a quick spooling set of compounds when they are unlocked. I like the way they drive, but I have also come to appreciate the quick response of a looser converter as well. I still feel like you would like the DK in your setup. From what I've seen in the trucks I've used them in, it is a good mix of both. It feels loose enough to respond well and get on top of the charger but couples well as the engine builds RPM.
 
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N2BRK

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The X is a very hard coupling converter that helps bring in the torque on a quick spooling set of compounds when they are unlocked. I like the way they drive, but I have also come to appreciate the quick response of a looser converter as well. I still feel like you would like the DK in your setup. From what I've seen in the trucks I've used them in, it is a good mix of both. It feels loose enough to respond well and get on top of the charger but couples well as the engine builds RPM.
The DK confuses the hell out me. Mike said it was made because they had supply issues making the R and it’s my understanding that it’s supposed to mirror the R’s specs, but they went about it differently. Looking at the data from Goerend, they are night and day. Of course Goerend’s data is based on 500ftlbs. I think Dave needs to set up a fleet of loaner trucks to try every possible combination 🤣
 

2004LB7

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If that chart Adam posted above holds any water, I think one would be hard pressed to tell the DL, X, DX and G apart from each other. The other three are probably enough difference that they are noticable but not those four. Maybe double the torque and test again and see how the chart looks
 
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N2BRK

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Low stall but high multiplication on the X. Interesting. That backs up what Josh said about the X coupling hard. It isn’t typical to have high multiplication on a low stall converter. It kinda confuses me a little more than I am already.

I’m still of the opinion that I should eat a bowl of alphabet soup and whatever letter is left in the bottom wins.
 

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pl_silverado

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who's running a limitless 1078? I picked one up used but haven't had a chance to install it yet.
 

malibu795

misspeelleerr
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Low stall but high multiplication on the X. Interesting. That backs up what Josh said about the X coupling hard. It isn’t typical to have high multiplication on a low stall converter. It kinda confuses me a little more than I am already.

I’m still of the opinion that I should eat a bowl of alphabet soup and whatever letter is left in the bottom wins.
Generally low stall means it fluid coupling happens sooner.
There is also the difference between from a stop and while moving.

I went round and round with Mike L, years ago, trying to pin down clear definitions, pretty much just pissed him off about it
Seams goerend got some basic stuff written down which makes for common ground
 
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N2BRK

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Hahaha. Sounds about right when I had my LMM and used to talk to Mike.

Evan seems to have a solid foundation on this stuff. He’s had a lot of seat time in various builds. I texted him a few weeks ago but didn’t hear back. Must be waxing his Hellcat 😇

The 1078 was great in both stock lmm and even after my friend got Mark’s 68stg2r in there. I don’t know about on an lb7 or lb7 stock/compound. My truck and his were the same build and the 78 flashed up a little more than my 1077. I liked them both.
 
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PureHybrid

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You also have to remember that the stall speeds listed can be pushed well past that on a modified truck. IIRC Mark B said he stalled a G up to 3k rpm in his white truck

It would be interesting to see the 1078 Limitless have the speed ratio charted like Goerend did. Maybe we could get Evan to send one over to Dave
 
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malibu795

misspeelleerr
Apr 28, 2007
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You also have to remember that the stall speeds listed can be pushed well past that on a modified truck. IIRC Mark B said he stalled a G up to 3k rpm in his white truck

It would be interesting to see the 1078 Limitless have the speed ratio charted like Goerend did. Maybe we could get Evan to send one over to Dave
Fluid coupling is highly subjective to engine HP/TQ and weight of said vehicle.. add in, trans/diff ratios/tire dia.One can get in the weeds fast lol.

I have a log still with a sun coast 1056 engine RPM ~3200rpm and wheel speed 1mph while hooked to a sled.

Love to see a 3 way test between Evan Dave and Phil
With their low stall, mid stall, and high stall version.

Test on a stock
~400/800
~500/1000
~600/1200
One would get in the weeds fast though with all the variables.
 
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