Tom 400 CFI

The truck has bigger diameter tires, so the 4.11 in the truck acts more like a 3.50, or so, in your car.

Can you just put in the trans and see how it is? Then change the rear gear if it's not where you want it to be? With your 3.42 and 27" tire you'd be at ~2270 RPM at 80mph, and that's not bad.....

QwkTrip

iTrader: (22)

That's what I would do too. It's hard to guess up front all the details about a car build. Easiest thing to do is get some seat time because it can change your mind what you do and don't want.

skinny z

With the 6L90, that's what I'd do.
Your 1st gear overall is a little aggressive although with a 27" tire, it's tempered somewhat. Your highway cruise RPMs will be satisfyingly low too with the 3.42.
Not too sure about the 28" tire as I'm of the understanding that it takes a little surgery to make them fit.
As for shift RPMs, with the E transmission and an aftermarket controller, I can pick whatever you'd like.

budget builder

iTrader: (3)

Beefed up 4l60 w/3.90 posi
Thx fellas

skinny z

So no 6L90.
The 4L60 has a 3.06 1st gear. That 3.90 is a lot of multiplication.
With my 3.73's and the 4L60, traction doesn't exist on street tires. There is a benefit at the drag strip though. But even then, my old, tired slicks weren't enough.
Cruise RPMs were reasonable with 80 MPH being about 2400-2500 RPM. All of the above with a 26" tire(~).

thatsupnow

Beef up that 4l60e all you want and it's still gonna be living on borrowed time. Put a 4l80e in there with a few mods and it'll handle big power no problem

skinny z

Define "big power".
I've had or been part of several 4L60s. With the attention needed all have survived thousands of miles of abuse at the 500/500 TQ/HP level or thereabouts.
GearStar's level 4 700R4 is rated to 650HP/600TQ.
Maybe ​​​​​​@vorteciroc has an informed opinion.
This isn't to say that you don't thatsupnow. But I do know vorteciroc was part of GM's Powertrain division.

budget builder

iTrader: (3)

Eggsellent!!! Hahahahahaha

As far as the 4l60. It gives 11.93 instead of the 15.71 I was about to screw up with..... thx fellas and please keep the knowledge coming.

skinny z

Mine: 3.73 at 75 MPH is 2531 RPM with a 26" tire (OD locked up).
Yours: 3.90 at 75 MPH is 2548 RPM with a 27" tire.
About all I can offer here is that I'm quite comfortable with my gear ratios in all ranges. Launch is good. Cruise RPMs are reasonable although there might be a mileage gain with a few hundred less in cruise. I say might because I've seen it where lower revs don't necessarily equate to decreased fuel consumption.

QwkTrip

iTrader: (22)

If you're not opposed to a manual trans then you can cruise on the highway nice with a T56 6-speed (0.5 ratio 6th gear).

The next craze coming down the pipeline (but still in its infancy) will be the ZF 8HP70 8-speed swaps. Give it a year and I think that swap is going to become more straight forward.

thatsupnow

700+ HP. I've also ran thru my fair share of level umpteen 4l60's that all claimed a decent rating of hp/tq and yea everything looks great on paper but again once the sticky tires came out and the abuse ticked upwards it was all on borrowed time. Personally I just got tired of fixing something that wasn't up to the task

thatsupnow

I think Andrew over on ls1tech has a thread for that swap he's currently working on

skinny z

I can certainly appreciate that. At 700 HP I'd be a little edgy too. Thrilled! But edgy.
At my power levels, these things tend to hang together. Now, that said, the proof will be this racing season when I'm back with the new and improved version X.0 of the engine. Still only 450/470 as predicted by the dyno (and less when installed for certain) but it'll be fresh sticky tires and drag strip duty every chance I get. Right now I'm dealing with the fiasco that the previous builder left me with. Plenty of high zoot parts in that transmission but it ***** the bed after 5000 miles with hardly a WOT pass made (long story).
Here's hoping.

skinny z

I truly enjoy driving a stick car. And that highway upside impresses me even more. As I get older the difference between efficiency and outright speed has tended to swing towards the former.
That said, even at my power levels, and certainly not yours, dumping the clutch at 4k is going to mean a big order from Summit for drive line parts. The auto tends to be easier on the hardware.

thatsupnow

I've got a transmission guy just this side of Kelowna that I've been going to for years and we decided that the 4l80e was the one to get. So I brought him a 99 core and a lvl 3 Jake's rebuild and recalibration kit plus added a few other billet parts on top of that and I've never been happier.

vorteciroc

Reliability and Longevity (REALISTICALLY) have not been a Problem for the THM700-R4 or it's Electronic-Brother (the 4L60E/ 65E/ 70E/ 75E) for about 20-Years.

At that point I would say that less than TEN Builders in the Country could have roughly 1,000+ HP in a 4,000 Lb Vehicle Reliably.
By 2014, there were plenty of Builders who were capable of doing so, just the same as today.

There are some very strong Hard Parts available, but more importantly the Hydraulic Modifications that are Required to make these Transmissions actually LIVE at those Power-Levels...
Have been shared well enough that pretty much anyone can Find a Builder capable of putting together a proper Unit.

I have about 3-Dozen THM700-R4 Units and about 6-Dozen 4L60E-Family Units currently out there at those higher Power-Levels...
And have been going on for quite a few Years.

The Only Issue that I have with these Transmission...
And the reason that I normally turn people away from them...
Is COST.

I do not feel that going past the 650 HP - 750 HP Range is a good investment, being that a Comparable 4L80E is less expensive.
Spend the same money on a 4L80E and you will have a better Stronger Transmission overall with room to keep going.
The THM700-R4 and 4L60E-Family Transmissions are Maxed-Out!

If anyone is looking for a THM700-R4 or 4L60E-Family Transmission... YOU ARE IN LUCK!!!

The Builder that Designed all the Transmission Offerings for Performabuilt (in PA) has separated from Performabuilt and is now on His own.
He currently has all 4-Levels of His 4L60E and THM700-R4 transmissions On-Sale!!!

His Level-3 Build (Rated 900 HP at 4,000 Lbs) is currently ONLY $3,100!
He says that Price includes Shipping to you in the 48-States, and there is currently No Core-Charge/ No Core Required.
NOTE! These are NOT for sale through Performabuilt.

He is Not a Sponsor here (But He is on LS1Tech.com)...
Please feel free to PM me for His Business/ Contact Information.

skinny z

Having moved from Ontario to Alberta ten years ago, I lost all of my racing contacts. Engine, transmission, and any fab work I couldn't handle myself. I was tightly associated with a chassis shop for a number of years and I truly miss that place.
This latest 4L60 came out of Ontario and the builder was well recommended. I spec'd the hard parts. Everything in the Sonnax catalogue pretty much plus the latest and greatest from GM. TransGo too. But somewhere along the way, the build went south. I ended with a transmission pan full of crud after 5000 pedestrian miles. Did a clean up and flush as best I could but 50 miles into the new engine break-in I ended up with a one speed in any selector position. It's on a bench now with yet another new guy. He's keen to save what he can and the cause of death is yet to be determined. From the sounds of it, the 3/4 clutch pack is fused together.
If your transmission guy was closer, I drive across the mountains for something that I know is going to work. He sounds like the real deal. Hell, I drove to Ontario from here to get the last one.

skinny z

Damn it! I've already got a guy in line. Unfortunately he's not performance orientated but seems very keen to give me a trustworthy product.
I've said it time and again. Timing is everything. I think that'll be my epitaph!!

Thanks vortec. I knew you'd come through. Now if only YOU were closer.

QwkTrip

iTrader: (22)

Nah, all I do is spin. Easier on parts that way.

skinny z

Hahahaha! True enough.

thatsupnow

Oh yea he's an amazing drive line guy. He's also a drag racer too. He's got quite a few high powered units running around the Okanagan that are living good lives. I recommend him to pretty much everybody I run into that's looking for a good trans guy. No BS with this guy too he'll want to know what you're gonna do with the car/truck and will come up with a plan or flat out tell you it's not gonna work and you need something bigger/better

skinny z

For what it's worth, I'm looking to get myself to Mission Raceway for some sea level racing. If all goes to plan (not that that's ever happened) it'll be an Ontario trip this summer to race at my old home track(s) with the fresh 357 and 4L60. And to that chassis shop and good friend I mentioned. I do need a little custom exhaust and /or a transmission crossmember built. But Mission Raceway would be a blast even if it's not for another year. I drove across the mountains once (Toronto to Edmonton to Vancouver) in a stock 84 Z28 albeit that was last century. And my teenaged daughter drove it back from the coast to Edmonton. Good times.

Anyway, I certainty hope our OP hasn't taken offense to the turn of the thread. But it's good to connect and relate with other third genners.

skinny z

Well, seeing as my transmission is on the bench waiting for the post mortem and plan B, is there a single source place where these modifications can be found?

My builder has no qualms about being supplied with additional information. He's a shop owner for your typical transmission service centre and he's offered to take on my rebuild as his own personal project. I can't argue with that. Perhaps other than to say does he have what it takes to build something that'll last even at my modest power levels?

I don't want to have to go plan C!

​​​​​

budget builder

iTrader: (3)

Hey, yall are fine. I love all of this. I hope yall don't mind me changing my mind from what I have calculated my 1st gear might be just a little high but I'm loving the 2nd gear instead of falling on my face after the 1-2 shift. 6l80/3.08 posi

thatsupnow

Actually sir we do mind!! Hahaha jk it's your build so do whatever you need to get where you want to be

budget builder

iTrader: (3)

yeah I think this is going to be my decision. I appreciate all of you

kestell123

What do you plan to source the 6L80/90 from? Be aware that some of the applications , the camaro for example do not use U-joints and do not use slip yolks. Rear wheel drive trucks and suv's would be the best choice for a trans. source . Also the 6L90 in rear wheel drive trucks have a very large out put shaft.

Fords88Bird

Wow lots of valuable info here from all u guys.
Excellent insight also from vorteciroc.

vorteciroc

What Model-Year is your THM700-R4?
Are you apposed to having a Forward-Pattern Full Manual Valve-Body?


Most Professional "High-Performance" Automatic Transmission Builders consider Their own Build-Designs/ Build-Modifications to be Classified: "Top Secret" Information...
And more valuable than Gold and Diamonds.
So generally speaking, said Information will need to be Paid for (as part of a Transmission Overhaul or Transmission "Shift-Kit")...
Definitely NOT considered to be FREE Information in most circles.

I will say that the majority of the Information for the 4L60E-Family (60E/ 65E /70E /75E) can be carried over to the THM700-R4.
Obviously there are differences... Most of which involve Pressure Control (Line-Pressure, Boost Pressure, Throttle-Valve Pressure, Modulated Pressure, Governor Pressure, Solenoid-Feed Pressure, Signal Pressure, Etc...)
There has been some shared Information here on THM700-R4s from Myself through Dana (Member: ProBuiltAutomatics) and from Dana directly Himself.

However, for those whom really have interest in this Topic...
I would gander over to the Automatic-Transmission Sub-Forum of LS1Tech.com...
As Myself and several others (On The Know) have shared a MASSIVE amount of Information over the course of many years across that Sub-Forum.

Not "ALL THE SECRETS" have been Shared, but realistically a substantial amount has been.
While I personally am NO LONGER in Business for Myself (Due to Health Problems outside of my control)... Many of the Members Post Information are in Business for Themselves.
The small amount of Information that they Retain/ Keep Secretive, is necessary in Capitalism in order to be Competitive among Their Peers.
So PLEASE do Not go hounding anyone for every last detail of what they do (Especially for FREE).

Dana of Pro Built Automatics has been very receptive to being OPEN to discussions with other Builders.
Please feel free to reach out to Him.

Taking Myself off of the Table/ Out of the Equation (Sorry I wish I was still in Business )...
If your Power Goals are in the 750HP - 1,000HP Range, I would put you into contact with the Builder that Created Performabuilt.
If your Power Goals are in the 1,000+, Trans-Brake need, or have some other Specialty needs, I would put you in contact with the Second-Best THM700-R4 Builder in the World.
(He however will NOT Share Information with your Builder... He will Only Sell you what you would need, and it's worth it).

budget builder

iTrader: (3)

See that's why it's important to be humble enough to ask questions. I didn't know this

skinny z

Good question.
​​​​​​It was all originally built into a case from a 91 Caprice. Went through several iterations until the torque converter eventually failed (2016). That trans was shelves (still have it too)
Then another was built and mistakenly used a case from a 91 Vette. There's no rear transmission mount on the case of that model. It's on the extension housing. This is the transmission that recently ate itself up (5000 miles) and is currently on the bench. Full of Sonnax and GM parts too.
My latest builder has politely requested that he not reuse that case as he doesn't know what kinds of modifications it my have seen.
So now, that question is unanswerable.
I'll take these inquiries off of the table for now. This thread isn't mine and my interests don't necessarily follow those of the OP.
But thanks as always @vorteciroc . Your knowledge and the sharing of it is truly appreciated.
I'll be checking out LS tech. My user name is 67LSX454. See you there.
No back to your regularly scheduled thread.

budget builder

iTrader: (3)

Got another question for you fellas OMG are all 6l80 or 6l90 transmission prone for failure even at my little power level?
and anyone recommend a stall speed for my application? I would like to go to Myrtle Beach every so often (2.5hrs) away I95 but that's just every once in awhile.....

kestell123

my 2013 corvette has 176,000 ,no problems . My 2007 GMC sierra has 235,000 with a L92 6.2 in front of it no problems. They started putting the 6L80 in the corvette in 17 years ago and in trucks 16 years ago, most are still going . The super charged camaro from the factory made somthing like 550 HP with a 100,000 mile warrenty, although that used a 6L90. I am sure some have failed but most are still on the streets. When I started planning my LS/6L80swap in 2012 I stopped at a local transmission shop to get their opinion of the 6L80 and they said they still had not taken one apart, none had come in with a problem. Now it could be that after only 5 or 6 years that the ones that had problems were worked on by dealers. Since 2007 Gm has made millions of trucks and SUV's and I'm sure you seen them still out there.

ShiftyCapone

iTrader: (7)

Most 6L80E failures are combined with DoD motors. If I recall, GM tuned the converter to slip during the V8 to V4 switch as to prevent the driver from feeling it. As such, the converters go out which takes some of the trans with it. This happened to a suburban I had at 100k miles with the L83.

vorteciroc

Mileage more than power will take out a 6L80E/ 6L90E.

They go after 100,000 Miles like clock work (Eating themselves alive from Debris)...
But You are also told not to Service it until 100,000 Miles.

Planned failure to get you to purchase a new Vehicle? ...YES!

budget builder

iTrader: (3)

"Gm manufacturers they have plans" plans" #heathledgerjokervoice

budget builder

iTrader: (3)

https://www.oreillyauto.com/detail/c...y/ptq8/t282131

soulbounder

Isn't the 6L80/6L90 and the newer 8 and 10 speed transmissions significantly larger than the 700r4/4L60? So much so that you might need to modify the body to fit them? I've never tried stabbing one in a 3rd gen but I can't imagine there is that much room available. I am a big fan of the 6L80 in my C6 Corvette. It has about 190k miles on it and it is great to be able to cruise at higher speeds. I don't think I hit 2k RPM until like >90 mph.

budget builder

iTrader: (3)

kestell123

When I did this swap I did raise the tunnel. I did not think that a 1/4 inch of clearace was going to work with a lot of HP trying move thing around. I have not seen Matt's car driving yet , maybe I missed it. I think Hawks has built one but I don't know what they did for clearance.

budget builder

iTrader: (3)

Another question, stalls? I was thinking 2800.. what's best and by the way looking for something bigger/better than the hot cam........ made a decision to say screw the warranty. Help, now it's about to get wild. Still looking ALL MOTOR. Just cam, springs, Rocker arms, stall, exhaust, ls3 intake,, 3.08, 6l80, term x max, and paint oh and better stereo., vette wheels sticky tires, tube k member, adjustable strut towers..... IM DONE!! I think

thatsupnow

Call a converter company like FTI or Circle D and tell them your setup and they'll get you what you need anything mentioned here is just talk. I got a 258mm pro billet converter from circle D and it's awesome

skinny z

I currently converter shopping myself.
I've 13 vendors on the go.
Is that Circle D a custom spec? I would assume so.

thatsupnow

Oh yea 100% . There's a mini Bible of questions to answer and you either state the stall you're looking for or just ask them for recommendations

vorteciroc

Who are some of the Vendors?

I have been using FTI for my sub $1,000 Converters with great success!
Let me know if they interest you... I'll direct you to a deal!

skinny z

FTI is on the list. @vorteciroc
I've a quote from Yank for their SS4000 (suggested it'll stall to 3600 given my predicted output). Single disc clutch. $1099 USD.
I'll also be contacting Circle D, Hughes, Edge, Coan, Vigilante, Neal Chance, ATI, TSI..
There are couple more that I'm unfamiliar with: Accelerated Torque and ProTorque.
I've had a couple of TCI converters. Both off the shelf models (I don't see where TCI does custom builds). One I blew up when I assembled the next to last engine (The one that eventually went south). Took out the input splines on the turbine. BANG!

Maybe the OP will find the above list helpful.

budget builder

iTrader: (3)

1. https://www.summitracing.com/parts/cca-54-703-11 or ws6 asa high lift cam

2. Pac 1218 springs
3. Stock rockers
4. https://www.circledspecialties.com/p...o-series-258mm
5. https://www.summitracing.com/parts/mgr-gm7-5-308t w/master install kit
6. https://www.spohn.net/shop/1982-1992...=1#description
7. Blackheart 2.5in 2 into 1 or dual system
8. Ls 3 intake
9. Term x max
10. https://www.summitracing.com/parts/upi-240331-r (this is a maybe

skinny z

$2000 for a converter!! Yikes! I guess I'm out of touch. I thought $1100 for a Yank was pricey. But I suppose that's what you pay for billet.
Looking further I do see a triple disc clutch. That's a $500 add on with Yank, so the prices are evening out.

thatsupnow

Prices on Circle D converters have gone up a bunch my 258mm from them was about $1400 shipped

skinny z

I sent in my request form. We'll see what they have to offer.