Is there a length difference between the 8L90 and the 6L90? I know the 6L90 is roughly 1.5" longer than the 6L80.
I didn't measure one but it appears to be the same length as the 6l80, supposedly the 8l80 is 3.6 kg lighter than the 6l80.
I'm not yet sure how much advantage there will be with the 8l80, in a 200 mph car like the Corvette 8 forward gears are good to have, in a 100 mph JK not so sure.
GM rates the 8l80 only 3.5%(up to 5%) better mpg than the 6l80 and the ratios are not far off:
6l80 4.03, 8l80 4.56
6l80 .67, 8l80 .65
The 8l80 has been internally modified for lower weight and less oil pumping losses. The 8l80 goes back to a traditional hydraulic controlled transmission but GM claims it can shift faster than a dual clutch transmission. Personally I think the 8l80 is a incremental improvement over the 6l80, going from the 4 speed automatics to the can driven 6 speeds made a huge improvement.
The Gen V engine is evolutionary, not revolutionary. GM has already got the OHV push-rod V8 to virtually compete with the best technology even Europe has to offer; and with less parts for better reliability. The two greatest contributions on the Gen V engine are continuous VVT and Direct Injection.
Direction allows better combustion efficiency which allows higher compression ratios. Injecting fuel at high pressure directly into the combustion chamber means more fuel gets burned in the combustion chamber and not wetting the the intake walls or back of the intake valve. So less CO's and HC's get out the chamber for the emission systems to handle. GM spent over 6 million hours of CAD design on the Gen V cylinder heads because that is where it all happens, the rest of the engine is basically an air pump.
GM was smart and stuck with a traditional low pressure fuel supply to the engine then an internal fuel pump in the engine to step up the pressure, this allows an easy installation.
We all know VVT helps broaden the power band but the current Gen IV engines are discrete VVT. The Gen V engines use contentious VVT to control the cam throughout the power band allowing smoother and more efficient power delivery.
AFM has been stepped up in the Gen V engines and they run a new engine mount to handle it. AFM is more aggressive and the Gen V engine can idle in a 4 cyl mode I am told. I'm not sure this will pan out well in our heavy JK's so we may turn it off in the heavy builds. If you look at the the driver side of the engine you will see a built in mechanical vacuum pump for power brakes. While in 4 cyl mode engine vacuum is low, so like the Pentstar JK's the Gen V engines run an auxiliary vacuum pump. On the Pentstar it is electric, on the Gen V engine it is a belt driven mechanical pump. This means you should not lose power brake assist even on steep trails at low rpm.
I firmly feel the Gen V swap will take the JK to a point no other engine/transmission combination can offer. Direct Injection, 8 speed transmission, CVVT and the simplicity and reliability of a GM power-train.
Even the new V6 engines are putting out over 300 HP so we are experimenting with both the Camero V6 and the new Vortec 4.3 to accommodate a low cost swap for guys that want the latest technology but don't have a big budget.
We continue to stay true to our MoTech module "bridge" and leaving the GM and Chrysler operating systems pure. This has many advantages including redundancies and fail safe stand alone operation. We have some Can bridge functionality now but have chosen not implement it, but you may see some in the future.
I also want to mention the trucks now appear to have a similar low profile intake like the passenger cars use. This will allow us to raise the engine up for better clearance to the suspension and othe chassis components. The Gen V engine also has an offset water pump allowing more clearance for the cooling fan.
I'm not sure if these pictures will show right away they say moderated.
Driver side, notice vacuum pump. Also notice newly designed hydraulic mount we will support.
First Gen V JK. You guys may remember the Silver Bullet, same guy owns this. This JK has already been built with axles rails, etc....He built this to wheel hard and not worry about scratching it up so it will be a good test for this Gen V swap:
Shop is full, looking to expand already. Notice Steve's LSA JK in front. It is running great(videos hopefully) and I like driving it, hopefully he will be driving it soon. We have to add brake pedal position sensors and some other electronics to support tapshift and cruise with the CTS-V OS. We finally got the WSS, brakes, AC, suspension, hydraulics. interior............finished: