Some videos I found on my camera

[DolSVT00]

^^^^^ Shifts like a Glide to me, but yeah that was 3 gears.................

[DolSVT00]

Thats it, the rest of them are just spinning and me cutting the camera off........

[gearmesh, inc.]

I was watching the tach on Matt's run. 2-3 shift only dropped the rpms from 6k to 5k. That's a loose converter!

I couldn't see the tach in Chris' truck, but I could tell by the sound of the engine that it definitely has a tighter converter.

Engine mod wise, how similar are these two trucks? Rear gear ratios? If very similar, 60ft times and ETs can be compared to weigh the differences between tight vs. loose converters in similarly built Lightnings.

A powerglide combo properly set up tends to have a converter that stalls at about the 70-80 percent mark of usable engine rpm. Matt's converter definitely hits that mark! Matt's 1-2 shift looks to be happening in just a short amount of time out the gate. With the 2.71 first gear ratio of the 4R100 with a loose converter, you wont travel too many feet before a 1-2 shift is in order to keep rpms in check. The tach does show a drop in rpm for the 1-2 shift, though. With all the noise from the exhaust along with the loose converter, I can see why it is hard to tell the 1-2 shift from the sidelines.

[DolSVT00]

Originally Posted by gearmesh, inc.

I was watching the tach on Matt's run. 2-3 shift only dropped the rpms from 6k to 5k. That's a loose converter!

I couldn't see the tach in Chris' truck, but I could tell by the sound of the engine that it definitely has a tighter converter.

Engine mod wise, how similar are these two trucks? Rear gear ratios? If very similar, 60ft times and ETs can be compared to weigh the differences between tight vs. loose converters in similarly built Lightnings.

Matt was on 28" tires, Chris was on 30's both on 3.73's Matt's 60's better so far but they've both been mid 1.4's. Engine wise the only thing thats the same is the short block, their both 9.6:1 forged motors H beams, pistons, cranks, externally balanced. The difference is in the heads and cam's and blowers, Matt's are Performance CNC ported, 1mm oversize ti valves with 135# springs ,and a set of comp 278xe's, with a KB 2.3. The KB doesn't have up top what the Whipple has so that's the reason for the bigger cam, we had to get some top end with it and its made to be spun pretty hard.

Chris's are JDM heads and cams, pretty much the same valves and seats but a lil different port, 120# springs and quite a bit smaller custom cam witch is great for a Whipple because they kinda lag on the bottom end but make it up up top.

The converter in Matts truck was ordered to be a 24-2600 triple disk from Cameron, the converter in Chris's truck is a PI 2600.

Honestly, I think Matts is working better I can mess with the lockup rates in the tune and probably get it to lockup a lil earlier but his seem's to leave a lil harder, he's gonna have to go to 30" tires here soon so we'll see what that does. They both are completely unique combo's to tune, some things work for one while it doesn't for the other.

Nobody has run a converter like that on any lightning I know of so their is not much to compare, they all go with the cookie cutter 24-2800 PI's

[slowgreen99]

I believe the "shifts like a glide" thing is due to only taking 1st gear to 5k rpms.

[DolSVT00]

Originally Posted by slowgreen99

I believe the "shifts like a glide" thing is due to only taking 1st gear to 5k rpms.

5600 by the logs, 2nd shifts at 5800

[gearmesh, inc.]

Originally Posted by DolSVT00

The converter in Matts truck was ordered to be a 24-2600 triple disk from Cameron, the converter in Chris's truck is a PI 2600.

It looks like Cameron underestimated the torque that that Lightning can make when he set up the stall!

Not only does engine torque affect stall speed, but vehicle weight plays a big part in the equation, too. I believe most performance converter shops don't get to experiment much with setting up stalls for 4400 lb gas trucks that often. That means they don't have much past experience to rely on to get as close to what stall you want the first time like they can with a 3000 lb car.

Years back, I personally experienced a too loose of a PI converter for an AOD I had in my old supercharged 93 F150. I ordered a 2800 and it ended up flashing to 4200! I called PI up and told them what it was stalling at and they asked for the part number on the front cover suspecting that the wrong one may have been sent to me. They said the number I had was the second tightest one they made for the 9.5" platform. Then they asked if my trans was slipping. I said it was a fresh build and the fluid smelled just like it came out of the bottle. I sent it back and they re-stalled it one increment tighter and it flashed to 3300. That same converter in a lighter Mustang would probably only have stalled to 2500 with the same engine.

Once you have some real world data on how the converter is acting, it is much easier for the converter builder to get close to your target on the free re-stall option.

[gearmesh, inc.]

Originally Posted by slowgreen99

I believe the "shifts like a glide" thing is due to only taking 1st gear to 5k rpms.

The tach needle can't keep up with the true rate of rpm rise. The datalog is much faster than the response of the tach needle. That's a 2.71 first gear ratio for you!

[DolSVT00]

Originally Posted by gearmesh, inc.

It looks like Cameron underestimated the torque that that Lightning can make when he set up the stall!

Years back, I personally experienced a too loose of a PI converter for an AOD I had in my old supercharged 93 F150. I ordered a 2800 and it ended up flashing to 4200! I called PI up and told them what it was stalling at and they asked for the part number on the front cover suspecting that the wrong one may have been sent to me. They said the number I had was the second tightest one they made for the 9.5" platform. Then they asked if my trans was slipping. I said it was a fresh build and the fluid smelled just like it came out of the bottle. I sent it back and they re-stalled it one increment tighter and it flashed to 3300. That same converter in a lighter Mustang would probably only have stalled to 2500 with the same engine.

Not only does engine torque affect stall speed, but vehicle weight plays a big part in the equation, too. I believe most performance converter shops don't get to experiment much with setting up stalls for 4400 lb gas trucks that often. That means they don't have much past experience to rely on to get as close to what stall you want the first time like they can with a 3000 lb car.

I would say both trucks aweigh similar and are likely in the 44-4500lb range at race weight Chris may be a tad bit heavier but not by more than 50lbs or so by what they both still have on the trucks.

Its working for now, i think when apples are compared to apples and their both running the same amount of boost and timing the MPH should tell the tale. I'm pretty sure Matt's running at least 2lbs more boost and 4* less timing than Chris, and Chris's MPH shows that, timing = MPH on these trucks. But he's not getting the 60's that Matt is.

[gearmesh, inc.]

Originally Posted by DolSVT00

I would say both trucks aweigh similar and are likely in the 44-4500lb range at race weight Chris may be a tad bit heavier but not by more than 50lbs or so by what they both still have on the trucks.

Its working for now, i think when apples are compared to apples and their both running the same amount of boost and timing the MPH should tell the tale. I'm pretty sure Matt's running at least 2lbs more boost and 4* less timing than Chris, and Chris's MPH shows that, timing = MPH on these trucks. But he's not getting the 60's that Matt is.

We'll just look at the extra looseness as a blessing in disguise for now!

[DolSVT00]

Originally Posted by gearmesh, inc.

We'll just look at the extra looseness as a blessing in disguise for now!

I look at it as....... if Matt swaps converters I'm buying that one off him because mines on 3.55's and that converter would probably help me alot.

[chrisheltra]

Thanks for the vid