ez2cdave

6-Speed Valve Body for 4L80E Transmission . . .

Has anyone ever heard of this product from a company called "Powertrain Control Solutions" (PCS) ?

"5/6-Speed Valve Body with Electronic Engine Braking Kit Including Solenoids, Internal Harness, Plates, and Gasket" . . .

Part Number: VBM-2000

I really like the gear ratio spread when the 2.98 gearset is installed and 4th Gear is "skipped", resulting in a 5-Speed 4L80E . . .

(1) 2.98
(2) 2.24
(3) 1.57
(4) Skipped ( would be 1.18 )
(5) 1.00
(6) .75

(R) 2.46

Thoughts ?

Jake's Performance

iTrader: (2)

I don't really understand the draw as it seems to be a novelty to me with no real performance advantage and several potential reliability concerns.

A 4L80E as designed is a very stout platform. Why compromise that?

ez2cdave

How would durability and strength be compromised, Jake ?

The ability to run a numerically lower ring & pinion, which would decrease cruising RPM and allow high top-end speed, which a lower ratio ring & pinion would reduce is a very attractive option.

Also, there wouldn't be a big "drop" between 1st & 2nd, like there is with a 4L60E.

The 2.98 1st Gear is slightly less than the 3.07 of the 4L60E, but the 2.27 2nd gear would pull much harder than the 1.57 of the 4L60E (Almost like 1st gear in a TH400 (2.48). 3rd gear would pull harder than 2nd gear in a TH400 (1.57 vs 1.48). 4th, of course, would be 1:1, with 5th being the .75:1 OD.

ez2cdave

My application is less than 450 RWHP . . . Thoughts ?

5.0 LsX

iTrader: (7)

the 4l80 doesn't have the same gear ratio as the 60, so the comparison is not the same... the 6 speed still has the same od ratio as a standard 80, so beside the extra gear shifts, I don't see any benefit..

mrvedit

There have been several threads on the TCI and PCS 6-speed 4L80E:

https://ls1tech.com/forums/automatic...six-speed.html

https://ls1tech.com/forums/automatic...ler-6l80e.html

https://ls1tech.com/forums/automatic...lp-please.html

Does anyone know if PCS is actually shipping the 6-speed valve body yet? I suspect that is what the PATC 6-speed 4L80E is using, but don't know if it is available "now".

As others are saying, it adds a lot of complexity and expensive, and likely won't make your car any faster. And Jake says it weakens the trans.
So if you want it for "6 speed" bragging rights, go for it, but if you expect better ETs, you might be disappointed.

ez2cdave

I'm comparing the gear ratio's from transmission to transmission

4L60E 3.07 - 1.57 - 1.00 - .70

4L80E 2.48 - 1.48 - 1.00 - .75

4L80E 2.98 - 2.24 - 1.57 - skipped -1.00 - .75 ( in this setup, the 1.18 "4th gear" would be skipped, making it a 5 speed )

Now, you can see those ratio's would be more advantageous for drag racing and allow a higher Ring & Pinion to be run (3.08,3.23, 3.42, etc ) without sacrificing a lower cruising RPM at highway speeds.

redtan

iTrader: (5)

So there's no performance gain whatsover in having a transmission with 2.98/2.24/1.57/1.00 gear spread vs. one that only has 2.98/1.57/1.00?

Jake's Performance

iTrader: (2)

Not necessarily,
Many cars go faster with less starting ratio and fewer shifts (think 2 speed Powerglide, or 2.10 gear TH400).

The lesser ratio helps traction issues with bigger power cars.
Even on the milder 500-750 HP stuff the 4L80E/TH400 ratios typically ET quicker than the 4L60E ratios.

The additional gear and ratio would be most advantageous for heavy combos for towing or street use.

poorhousenext

I think the advatage in gearing is not with 5sp setup but 6 speed setup. The 6th speed setup has 1.18 4th gear. I run a 3.55 rear gear.

1.18 X 3.55 = 4.19 4th gear ratio.

RPM lost between shifts is less than than 4L80E in every gear. In 1/4 mile I do have one more shift, than I would with 4L80, and it's a moot point in RPM lost in 3rd to 4th gear shift, and RPM lost, any shift is is less than 1/2 that of 4L80 so in my opinion extra shift is a moot point. Get the weight moving with close ratio gearing and keep it moving.

If your like me and run a TQ cam that makes it's peak HP at 5800 RPM, I believe the 1st-4th gear ratios of 6sp makes for a lot of fun, on street or at the strip.

350 RWHP, 3400lb car with 3/4 tank of gas, 3635LB with driver.

117.93 MPH in 1/4 Mile. Converter is only stalled at 2800 RPM. Only 14 of the MPH is picked up after 1/8 mile. Did gearing help? No way to say for sure, unless I had tried running a 4L80 with a 3.55 rear gear 1st and then swaped to 6sp Version, but I sure the hell believe it does.

HexenLord

I see very few real world circumstances where the 6-speed version would offer any performance gains, especially for the cost/effort invested.

Jake's Performance

iTrader: (2)

Only 14 mph gain on the backhalf would usually point to something being wrong, a fuel delivery issue, running out of gearing, blowing through a converter, etc.

You have probably a near ideal combo for the 6 speed. Low power, medium weight car, and tighter converter, moderate rear ratio. I think a bit less rear ratio would possibly make it work even better for your combo.

However,
Most of my customers are making double to quadruple the HP that you are. They would toast the 6 speed version of a 4L80 in short order and the ratios would be wrong.

Also anytime you alter the gear ratios for greater ratio, you weaken the gearset all else being equal and due to space, you pretty much weaken it no matter what you do on a 400 or 4L80E. Adding pinions spreads the load but other parts are compromised.

I've had customers bring me 4L80E's with the 2.97 gearset, broken, from fairly mild combos. We use a different gearset that is manufactured differently, but it's not cheap.

The PCS VB is available, I spoke to one of their reps yesterday.

ez2cdave

Precisely what my setup will be . . . Full-weight 2000 Z28, LQ9-based motor, 4L80E, 12-Bolt or S60 rear end . . . About 4000 lb with Driver and a full tank of gas . . . Daily-driver with occasional trips to the strip to run it in the "Footbrake" class, with ET's slower than 11.50's ( no roll bar needed ), probably high 11's - Low 12's . . . Right around 450 RWHP.

Jake's Performance

iTrader: (2)

A 2.75 gearset, 4 speed 4L80E with a good converter would serve you well and be much less expensive.

ez2cdave

What are the other ratio's, besides the 2.75 1st gear ?

Jake's Performance

iTrader: (2)

2.75/1.57/1.0/.75

poorhousenext

You brought up and interesting point about there only being a pickup of 14 MPH after 1/8 mile MPH. I just checked what MPH would be at cam's HP peak of 5800 RPM. With 3.55 rear gear, 28.3" dia tire MPH is 117.

Now I do have an intake air volumn problem due to intake tubes dia and not getting intake tube up to 4.0" before where tubes feed into MAF. I'm in the prosess of correcting that now. MAF change to LS3 style jumped TQ big time, but TQ stills falls off before it reaches cam design TQ peak RPM. Got no increase in HP or TQ at 5225 over what it was before MAF change, so will upgrade intake tubes size to 4.0" dia.

But again, I'm beating a Dead Horse after 5800 RPM so mechanical advantage of 1.18 4th gear may help engine pull cars weight after 5800 RPM.

Most of the people you deal with cam's make HP in 6500-7500 or up RPM range. Question is can I get car my car in low to mid 11's with street tires (no DR's are Slicks) a 1.9 60 FT time with a TQ cam rather than a HP one. Maybe even high 10's if I can get 60 FT time down to 1.5/1.6 time.

TQ is fun. You may not be going anywhere fast, but you feel like you are...LOL

Before MAF change.



After MAF change.



Picture of probem.

ez2cdave

Doesn't that kind of put it back in to the "big drop" situation of the 4L60E ?

Is there an option for a different ratio in 2nd gear, too ?

mrvedit

Thank you for that info. Hopefully they are not pestering you too much as I may have given the company your name as an excellent builder prospect.

Jake, we know you have reservations about the 6-speed and it might not be suitable for your 800+ HP customers, but if you are considering expanding your business, this might be a dandy. I'm sure everyone on the various forums you support would rather buy a 6-speed from you then from TCI or PATC. And if anyone can make it work well, it is you.

Regardless of whether a 6-speed 4L80E would improve anyone's ET, some people simply want one. Also the additonal ratios with paddle shifting would be very useful for road course racing.
Hey, just my 2 cents.

RevGTO

iTrader: (12)

We use loose converters with the 4l60e because of the big drop between gear ratios. That becomes progressively less necessary as the drop tightens up, as in the case of the 4l80, various A6's. The point in any case is being able to keep the motor in the heart of the powerband.

In road racing or just general driving, where one is not at constant WOT, being able to do so with less slippage is a good thing. Drag racing is a whole different animal.