Repair-It

I think the factory rev limiter is around 5300 or 5400 rpm in the B-body LT1. It's pretty much done making power at that point anyway with the stock cam (HP peak is 5000).

There is probably good reason to run the 1-2 as high as possible given the wide ratio spread between 1st and 2nd on the 700R4/4L60E. But the 2-3 and 3-4 can be a bit lower. It is possible that some shifts on the non-9C1/SS calibration may begin BEFORE 5,000 rpm so I'd change that in the tune. I think the HP peak is 5,000 rpm so you would, at the very least, want to rev it to 5,000. Realistically a bit beyond (due to ratio spread).

Spread between 1-2: 1.882x
Between 2-3: 1.625x
3-4: 1.434x

So based soley on that, you would lower the shift RPM for each successive gear change. From an engineering perspective, the ideal shift point calculation is simple: shift when the torque at the wheels (same as power at the wheels/engine) in the current gear falls to what it WILL be in the next gear. In many cars this is right at the rev limiter. Some modern engines with small turbos, not so much.

By some miracle I found this:

Assuming a TC slip RPM of 200 after the 1-2 shift (I could simply test this on my car - it could be a bit more but I doubt it's less), here are some tables: You can see how different the ratios are spread between the gears based on how different the new RPM is after each shift. I believe the way this model works is I am adding 200 rpm of slip after the shift, but none before. That may be exaggerated but probably gets the point across reasonably. If the slip was the SAME before or after a shift (and it is a very tight converter so maybe that is possible), I should use the non-slip numbers.

But here's the deal. Even if you run it out to the rev limiter (which is beyond the HP peak, in fact it is down by like 17 from peak), RPMs still fall to an RPM that produces LESS power than even at 5400 rpm. Even to get an ideal shift at 5400 (instead of beyond), the RPMs would have to fall to only 4200 after a shift. And you can see the 3-4 gets close because the ratios are in fact tighter there. But still not optimal.

However - there are also diminishing returns. What I did was look at average HP between the shift point and the new RPM after a given shift. Higher average HP should equal higher performance, most directly. Again, that assumes equal time at each RPM, at least within a given gear.

Here are some numbers. Side note, this is why aftermarket torque converters make such a huge difference on these cars. Between the wide ratio spread of each shift, and the very tight factory converter, a looser (but efficient) converter would really help keep RPMs up after shifts and get more power to the road.

My simple analysis is this:
Given the wide 1-2 spread, the higher the 1-2 shift point the better. Run it right to 5,400, which should be around 40 mph after 3.42s. It hits 260hp @ 5000, and revving 400 rpm beyond that HP falls to 243. However, after the 1-2 shift, engine power is around 192! If it shifts at 5,000, engine power after the 1-2 is even lower at 180.5!! The higher the better on the 1-2. Hence, average power shifting 1-2 at 5000 gives you around 228hp. But shifting at 5400 gives you 236. Is that a huge difference? No not really but it should be statistically significant.

The 2-3 is similar. Run it right to 5,400 in 2nd which should be around 76 mph after 3.42s. RPMs fall to around 3500 and average HP is 245. With a 2-3 at 5000 average HP is only 237 so another gain of about 8 hp. Probably still worth it. Even more so when you factor in time. So in the higher gears, you spend more time at any given RPM because the car is accelerating slower. You want to be at the highest engine HP possible at any given time which at 5400 is 243. After the 2-3 it falls to 3500 which is only 216hp. If you are going up a hill for example trying to pass someone, and you nail it and the engine downshifts to 2nd at 5000rpm to accelerate to 5400 (this would be a 70-76 mph example) you're averaging like 254 hp in that range. That is WAAAY better than if it could NOT downshift in which case that same 70-76 mph pass would take place in 3rd from 3060 rpm to 3300 rpm which has an average HP of only 198. That is a HUGE difference. It would totally change the character of the car, just by raising the upshift points and allowable downshift MPH. In other words, for every scenario that you can allow a full downshift and let RPMs run into the 5000 range, instead of only the next higher gear and RPMs in the 3000s, you are going to dramatically improve the performance of the car in those situations.

Now by the 3-4 shift you start to see diminishing returns. The extra average HP provided by a 5400 rpm 3-4 (vs a 5000) is only 5. I say only 5 because a 5200 rpm WOT 3-4 still provides 4 more HP. Not to mention, you are going like 115 mph at this point so hanging the engine at these RPMs is sort of not worth it. Just let it shift. I would propose something in the 5000 to 5200 rpm range for the WOT 3-4 based on this. After a WOT 3-4 at 5200, new RPMs are 3800 which is WAY better than the 1-2. Instead of falling down to below 200 hp, power is around 229hp after a WOT 3-4 @ 5200. Even after a WOT 3-4 at 5000, RPM drops to around 224. Still better than ANY 1-2 scenario. In fact, average power on a WOT 3-4, as shown above goes from 245 with a 5000rpm shift to 249 with a 5200rpm shift to 250 with a 5400rpm shift. Clearly not worth winding all the way out for a measly 1 hp average gain. But all of these numbers are better than even the best case 1-2 which provides 236 average doing a 1-2 at 5400, which is STILL less (by 9) than the WOT 3-4 at 5000. So a 5000-5200rpm WOT 3-4 should occur between 115 and 119 mph or so.

To accomplish this, it will require some trial and error because most of the shift point stuff is done by MPH not RPM. I will end up having to raise the fuel cut a little just to avoid accidently hitting the rev limiter before a shift can take place. Plus, again, I will have to account for torque converter slip but at those RPMs it shouldn't be much. At a minimum, if I didn't want to do all that, I could simply take the SS/9C1 shift tables and adjust for 3.42 gears (from 3.08) which would still probably make a pretty noticeable difference.

Info: http://www.gearhead-efi.com/Fuel-Inject ... 10f2f337f7

Well DUH.

First thing I found out was the 1995 Cadillac LT1 with towing package RPO V4P was a drastic improvement in shifting from factory! Can you believe a Cadillac had better shift points then an Impala SS? Well it does. So I found the V4P bin file and did a lot of comparing and liked the looks of it.

Driving my 1994 RoadmaSSter, that has the towing package, but same shift points as Impala SS was much better, higher shift points more performance oriented and just felt better.

The only other thing I have done to tranny is changed was "Shift Time (sec) Vs. %TPS Vs. Shift, Normal Mode, Low Alt. and High Alt". I cut the shift time in half from approx .60 to .30 and they do seem firmer.

The only reason I touched them was there is another table "Shift Time (sec) Vs. %TPS Vs. Shift, Performance, Low Alt. and High Alt" and these are all set to "0.00 But have no idea what makes the PCM go from "Normal" to "Performance" mode. I'm guessing I will find a TPS parameter somewhere. But both tables are the same TPS readings? So maybe it's switched by a MAP reading?

I should get my hands on a V4P calibration and copy all the trans tables. Then maybe the only thing I'd really have to do is give the shift points just a bit of a tweak to hit the goals from the previous post. I may also still want to raise the downshift thresholds (tighten up the hysteresis) if it still doesn't want to downshift as eagerly/quickly as I want. But this is exciting. The V4P was a factory 3.42 car. Bingo.

Don't go on...
https://www.impalassforum.com/threads/r ... s.1316046/

I would recommend NOT raising the shift points on the stock valve springs. Stock shift points are higher than those springs can handle as is...

This guy is the original "V4P is awesome" guy.

They talk about V4P trans settings.

https://www.cadillacforums.com/threads/ ... ned.68911/

There are some things in here:

The car really 2 totally different cars with the programming as V4P vs non. Even the tune I have that was "from a professional" maintained most of the stock shift points or close to them with increased line pressures. I feel the engineers who did the V4P program really spent a lot of time with the car tuning it, where the non V4P feels much more generic. Although, likely much better for mileage, as OD comes in much lower rpm.

Note that the V4P shift points are geared around a 235 70 15 tire. So an B/D body with shorter tires (like the Impala SS wheels) may not be so happy with them. But if you have a 3.42 geared car with the stock size tires, I would highly recommend it.

The most significant difference I see is shifts are 1-2, 2-3, 3-lockup, 3-4 (TCC unlock) and then 4th lockup. Where the stock non V4P program has more variation in the shift pattern, similar to 1-2, 2-3, 3-4, 4-TCC being the more common shift scenaro. I guess when trailering, it is more important to tow in 3rd than 4th, and the potential to have the trans go into 4th and unlocked converter is much higher, which could result in early trans overheat and potential failure in comparisson to the V4P program.

So that's all fine. But then he says this:

Just for giggles and grins, to see how the car handled the non V4P shift patterns, I copied in all the Corvette shift points, TCC engage/release and pressures (shift points and TCC lockups are close to stock Fleetwood/Caprice/Roadmaster) to see how much difference there is to my stock V4P programming.

The change was dramatic. Interesting enough, it felt like I added 1000#'s to the car. Much slower off the line than stock, much harder to spin the tires off the line, and generally just not as lively. If driven mild, it is ok, but the car really felt much softer. Yes, I can see this car being much slower down the 1/4mile with these shift patterns. Mid to high 15's would be expected. With V4P, I would expect much closer to 15 flat. Very dramatic results in how the cars low end performance is improved.

I was hoping to go a week or so and see mileage, but I couldn't take it that heavy feeling, so I set it back to V4P settings.

You sure can come out of the hole fast in a V4P car, I can say that for sure. With the Corvette shift points/TCC/pressures, it was not all that enjoyable to drive off the line.

I can smoke the rear tire anytime I want (with TCS off) with not a lot of effort. Where with the Corvette tune it was difficult at best. You had to really work at it, where with the V4P trim you can just nail it the gas and smoke em!

I am using the V4P as a pattern, and adding in some patterns of the 9C1 and my own tastes to get it to match. Keeping V4P pressures as a general rule. Some of the "pro tuned" pressures and Corvette made the 1-2 shift almost harsh.

Dave on shifts points affecting off the line, none. On pressures, I suspect the converter stall is affected, but hard to say, it didn't feel like it, but it felt sluggish in comparisson to the stock V4P setup. The stock non V4P has much lower pressures from 0-25% than the V4P has. Not sure all what that could affect in the trans to make it feel that way.

He lost me. I don't understand at all how trans settings impact hole shot stuff unless there is some underlying torque management (like burst knock) and he's changing more than just trans tables. But trans tables alone? I don't see how that would impact the off the line stuff. His description really seems like the difference between burst knock retard and turning that off (which is on my list for my RMS).

Drove it about 180 miles yesterday. I even used the A/C the entire time as it was extremely humid and gross. And by used the A/C, of course I mean I set the auto climate between 68-70F and it does a great job without having to touch anything at all. Jamie was in the car for all of 10 seconds when she looks at the dash and goes "this doesn't have dual zone climate?" She was anticipating being cold of course, not that she's a feature snob like I am.

There were zero issues. It ran well, I don't think there were any fluid leaks, no lights on the dash, no funny smells, etc. It drove smoothly at highway speeds which may be surprising considering the time it has sat on the tires.

Irritants for driving long distances:
1) Too much dead travel in brake pedal. I can't stand this. Some of it is the drums, maybe I still have air in the lines. Not sure. I don't know if it's air because once engagement happens, the feel is typical B-body firm. Swapping to my Caprice axle and doing all of the associated work should cure this. EDIT: I just drove the Ram to the transfer station and for normal driving that brake pedal feels substantially better.
2) Inconsistent power steering assist (left vs right). This is very annoying. I prefer turning right as that is the normal assist level. Turning left requires more steering effort and it does not feel normal to me. Plus the idler arm is sloppy which just makes everything worse. I still think I would swap to my Caprice's entire steering system but like the axle swap, that is kind of a significant project (linkage-only not too bad but would require an alignment). And like with #1, the parts are still on the car (rusting as we speak). Despite this it actually tracked pretty damn well. A lot of the time the steering wheel is dead centered while driving straight. This is surprising to me for several reasons, including the power steering thing.

For the drive, the bluetooth receiver with FM transmitter worked the whole time. The FM part sounded fine, no interference or static at the volumes I had it at (music at family friendly volume levels plus Google Maps voice guidance). Once or twice it seemed to disconnect from my phone. Not sure what that was. But like I said it only happened once or twice.

Maybe item 3) More fun facts related to road trips, I had some issues with GPS on my phone. Granted I had the phone wedged under the center arm rest for some of the drive. Then I placed it sideways on the seat in front of the armrest. But I still had intermittent GPS issues. I finally realized that the damn Sungate windshield was probably causing GPS reception issues depending on direction I was driving and whether one or more satellites needed a line of sight path through the windshield. It could be that getting a windshield mount would allow better reception but not sure. I guess the same thing would happen if I used a Garmin. I assume getting the device up from the height of the seat would help.

Anyway this is legit. Even E-Zpass knows about Sungate windshields. I had to get a front license plate transponder because they don't work from the normal windshield mount location. The windshield contains micro flakes of metal that blocks more UV (or IR or both) from the sun and that also blocks radio frequencies. Sungate windshields look purple through polarized sunglasses, further evidence that they are different.

So I guess I have a list of "watch items" for the Fall road trip. Frankly I think I could go right now but it would be less enjoyable until I address each of these items.

Drove the Roadmaster to work today. It was fine. A/C worked, too.

I like the car and I like having a simple car but other than slapping my old Caprice parts on it, what else am I going to do with it? I guess just....have a black Buick version of my Caprice that's a little faster?

A little paint correction action.

Came out pretty damn good. I did the hood, trunk and roof. Paint was definitely....weathered.

Used my new Bauer multi-speed (and speed controlled) DA. Harbor Freight's best. $100 with coupon.

It was very satisfying.

I treated the hood to a round of swirl remover as well. Then I ceramic coated the surfaces that I buffed.

https://1drv.ms/f/s!An5lt1BKvFKdqbUt9NBuJC8zTfsIJw

All the beading.

kevm14 wrote: Sun Jul 19, 2020 7:29 pm https://1drv.ms/f/s!An5lt1BKvFKdqbUt9NBuJC8zTfsIJw

Refresh link to view interior shots from today. Cleaned and then protected many surfaces with 303.

I put this Craigslist ad up last weekend.

https://providence.craigslist.org/cto/d ... 11075.html

I have received a lot of interest, with 8+ humans inquiring.

I ended up making a deal with a guy in Texas who was first going to fly up and drive it back and then looked into shipping. He went back and forth between wanting it with all wheels and just the stock wheels because I think it was a budget issue. He agreed to either the full $2,300 with stock wheels or I said I could do $3,000 with all wheels.

But the shipping quotes are higher than when I looked into shipping from TX to RI for some reason (was like $1100-1500+ whereas it was more like $800 back in April). Ultimately he kept promising money and never came through so I went back to 4-5 solid inquiries and said, hey, second chance, any interest?

Of those I got like 3+ hits and ended up making a deal last night with a guy from Framingham who seems like the exact guy I wrote the ad for. A deposit check is in the mail and I am going to end up delivering the car from him as he doesn't feel comfortable driving down, sitting with me for a test drive, etc. So he basically just agreed to buy sight unseen though we'll close the deal in person. He loved the SS wheels and said a couple factors are making him impulse buy this car:
- The way it presents overall and specifically on the SS wheels. He said it makes the car.
- My extremely descriptive ad.
- My Youtube video which shows my house/driveway/fleet all in neat and functional looking order which he said speaks volumes about me (as opposed to the car surrounded by, well, garbage and crap everywhere).

I said, I'll give you the same deal as the other guy - $3,000 on the SS wheels, and I'll deliver the car. He agreed.

I told a couple of the guys who got back to me that, sorry, it's sold AGAIN. They reminded me that they carry cash so, point taken.

This won't really be closed until next weekend but I am getting a good feeling about this guy. FWIW, he will care for the car - he even has a car cover specifically for it. I've been trying to explain to Bill that these people are out there and it only took a week to find someone like this. I guess he has some 60s Buicks and also a Corvair. It doesn't matter that MOST people don't care about it, I only need to reach the one enthusiast with my ad, and I clearly reached at least one (well, two, but the first guy apparently didn't really have the money which is too bad for him - I blame the shipping cost and I guess and inability to think through the whole transaction instead of insisting he's going to buy it before he was actually able to - not going to hold the car without a deposit at least).

At the risk of getting ahead of myself, if this one goes through next weekend, then I would say this actually has been far easier than most buying processes. Only took 2 weeks (usually takes way longer to buy a car from start to finish), and I won't have had to do any showings other than the final purchase. I went into it with dread but this hasn't been that bad. Bob may have even encouraged me to sell random junk from my basement (or Maxima parts) on CL.