WHYDTYTT: What Have You Done To Your Truck Today?

[Gary Lewis]

With the T-19 Big Blue's old engine was turning 2400 at 65 and it would get that 11.58. With the ZF5 the new engine is turning 1800 at 65 and I'm still getting about the same MPG. So if you are doing that with a C6 you are doing very well.

Makes me wonder if everything thing is correct with gallons and mileage. I pumped what I pumped and my odometer is close per mile markers.

The original owner, I’m told towed RV’s with it. And it has the old Torklift tiedowns for a truck camper, had a fifth wheel hitch in it, and a hitch for conventional trailers.

Wondering if they put a different torque converter in it.

Jim - I think you are right. Scotty poo poos the Edelbrock cam that was in the old engine, but my guess is that it is a lower RPM cam than his. I know the old engine pulled like a tractor from idle and this one doesn't wake up until ~1200 RPM.

Dane - They may well have put a different converter in, and I've read that can certainly help with the slippage.

As for the MPG, it is hard to get a good reading on a couple of tanks due to the variability of filling the tank(s), but you are still getting good numbers even if they are off a little bit.

[Rusty_S85]

Rusty, it was turning around 2600, it has stock 3.55 gears in it. And iirc, 265/75-16 tires.

I may have mentioned, every truck I’ve owned but this and my Bronco, have had 4.10 gears. I really like the 3.55’s. Good enough to pull and much better on the freeway.

I recalculated the two segments of my trip. It was 10.88 and 11.58 MPG. As Gary mentioned, good for a C6.

And I am surprised.

Nice. I would love to run more gearing but with the speeds I will have to drive and the rpm range I would have to keep them in for ideal efficient cruise range I am quite limited in gear ratios. Im hopeful the Hughes converter I plan to use the XTM will help me out if I understand it right it pumps 7 quarts more fluid per minute than OE, it multiplies torque more than OE and advertised 1,800 rpm flash stall which behind my 306 should be lower around 1,500 rpm and this converter on some sites goes so far as to state like on jegs a increase in fuel economy by 1 to 2 mpg.

For me the less slip, more torque multiplication, higher fluid volume was enough to sell me along with the anti baloon plate but the 1,500 rpm stall and + 1-2 mpg is nice too for me with my goal of squeezing as much economy as I can as well as much torque and power.

They say you cant have your cake and eat it too and I say wrong I will be having my cake and eating it too. That converter coupled with the E4OD planetary gear set with quicker 1st and 2nd gear with the extra torque multiplication and hopefully a 3.25:1 axle ratio I feel I should pull as if I had 3.55 gears but still be able to keep 65 - 75 mph with in my sweet spot Crane cites for my cam for efficency on the highway.

[Rusty_S85]

I imagine the cam in your new engine is not close to optimized for 1,800 rpm.

Lugging an engine below its design is really bad for fuel mileage.

Simple math for a simple pump would tell you how much less mixture you are pumping through it, and with everything else being the same (drag, rolling resistance, etc.) in theory there would be a direct relationship to rpm.

Why I went with crane for my camshaft they did the work for you and give you a rpm cruise range for the most efficient rpm range for the cam at highway speeds. My cam is 2,400 - 3,000 rpm, so everything I do is to put 65 - 75 mph with in this 600 rpm range.

Hopefully with the sniper stealth I can have it dyno tuned to be a bit better by leaning the engine out for cruising where its needed and enriching it only where its needed to prevent detonation and promote power production.

Why I laugh cause people still tell me that I should be running a Performer RPM intake cause it performs the same down low but makes power higher up. But I dont need it though cam only makes power 1,400 - 5,400 so a intake good to 6,500 rpm is just a waste. Plus with the sniper stealth I have to run a spacer place a 4 hole plate to prevent the dreaded IAC whistle that so many people have and this plate will help increase plenum volume and being divided it will help promote low end torque production as well as adding more volume for higher end so I should be still pulling good at 5,000 - 5,500 rpm. I also cant run the RPM cause if you have horrible throttle geometry it will result in a harsh snap as you try to over come the throttle plates resulting in jerky jack rabbit starts as you wont be able to lightly feather the throttle from a stand still it will go from 0% TPS to nearly 50% TPS instantly. My line of thought is the Performer intake is about OE heigth with the 1" plate it should put my OE throttle bracket at the proper OE heigth and if need be I should be able to make minor tweaks to get the throttle cable ideal for cruise control operation as well as a soft throttle pedal. Plus this intake has a boss where I can drill the coolant passage and tap it for the sniper TPS sensor so I wont have to use a bushing and the vacuum port on the rear of this manifold will allow my vacuum tree to be used for power brake booster and my vacuum modulator via vacuum tree on the firewall. The Performer RPM has this port under where the throttle bracket would mount.

If I was doing this some 8 years ago before I started building these custom cars at work I wouldnt have taken all this into account and would be making numerous mistakes but because I have I am able to piece it together for what I need that will work together for my goal.

[Rusty_S85]

Jim - I think you are right. Scotty poo poos the Edelbrock cam that was in the old engine, but my guess is that it is a lower RPM cam than his. I know the old engine pulled like a tractor from idle and this one doesn't wake up until ~1200 RPM.

Dane - They may well have put a different converter in, and I've read that can certainly help with the slippage.

As for the MPG, it is hard to get a good reading on a couple of tanks due to the variability of filling the tank(s), but you are still getting good numbers even if they are off a little bit.

Converters can, Hughes has a fuel miser converter that has reduced slip to improve fuel economy.

The XTM tow converter I am looking at for a small block C6 application has an advertised flash stall speed of 1,800 which is for big blocks for a C6 it should put me around 1,200 - 1,500 rpm flash stall. This converter also is stated on jegs site to improve fuel economy by 1 to 2 mpg. When I called the tech line at Hughes for a recomendation the guy I talked with basically told me this XTM has a lot less slip than the OE converter and we know slippage is heat and bad fuel economy.

[ArdWrknTrk]

I imagine the cam in your new engine is not close to optimized for 1,800 rpm.

Lugging an engine below its design is really bad for fuel mileage.

Simple math for a simple pump would tell you how much less mixture you are pumping through it, and with everything else being the same (drag, rolling resistance, etc.) in theory there would be a direct relationship to rpm.

Why I went with crane for my camshaft they did the work for you and give you a rpm cruise range for the most efficient rpm range for the cam at highway speeds. My cam is 2,400 - 3,000 rpm, so everything I do is to put 65 - 75 mph with in this 600 rpm range.

Hopefully with the sniper stealth I can have it dyno tuned to be a bit better by leaning the engine out for cruising where its needed and enriching it only where its needed to prevent detonation and promote power production.

Why I laugh cause people still tell me that I should be running a Performer RPM intake cause it performs the same down low but makes power higher up. But I dont need it though cam only makes power 1,400 - 5,400 so a intake good to 6,500 rpm is just a waste. Plus with the sniper stealth I have to run a spacer place a 4 hole plate to prevent the dreaded IAC whistle that so many people have and this plate will help increase plenum volume and being divided it will help promote low end torque production as well as adding more volume for higher end so I should be still pulling good at 5,000 - 5,500 rpm. I also cant run the RPM cause if you have horrible throttle geometry it will result in a harsh snap as you try to over come the throttle plates resulting in jerky jack rabbit starts as you wont be able to lightly feather the throttle from a stand still it will go from 0% TPS to nearly 50% TPS instantly. My line of thought is the Performer intake is about OE heigth with the 1" plate it should put my OE throttle bracket at the proper OE heigth and if need be I should be able to make minor tweaks to get the throttle cable ideal for cruise control operation as well as a soft throttle pedal. Plus this intake has a boss where I can drill the coolant passage and tap it for the sniper TPS sensor so I wont have to use a bushing and the vacuum port on the rear of this manifold will allow my vacuum tree to be used for power brake booster and my vacuum modulator via vacuum tree on the firewall. The Performer RPM has this port under where the throttle bracket would mount.

If I was doing this some 8 years ago before I started building these custom cars at work I wouldnt have taken all this into account and would be making numerous mistakes but because I have I am able to piece it together for what I need that will work together for my goal.

I'm not sure where my reply to Gary about his cam turned into a wall of text about intake manifolds, but whatever..

I also can't say much about stock cast iron intakes for the 302.

The one in my '85 GT didn't last any longer than the 4180, but that was long ago and I was a different person at 20 something than I am now.

I put the rear bumper back on my truck yesterday, after rattle canning the lower rear corners of the bed so I don't have to remove it for paint.

Hopefully I can find some time to wet sand and shoot the rest of it soon.

My tailgate letters are here but the new emblems are on a slow boat from China.

I'm going to need a hand to get the rack off if I want to paint the cab roof.

 

[Gary Lewis]

I'm not sure where my reply to Gary about his cam turned into a wall of text about intake manifolds, but whatever..

I also can't say much about stock cast iron intakes for the 302.

The one in my '85 GT didn't last any longer than the 4180, but that was long ago and I was a different person at 20 something than I am now.

I put the rear bumper back on my truck yesterday, after rattle canning the lower rear corners of the bed so I don't have to remove it for paint.

Hopefully I can find some time to wet sand and shoot the rest of it soon.

My tailgate letters are here but the new emblems are on a slow boat from China.

I'm going to need a hand to get the rack off if I want to paint the cab roof.

Progress, Jim!

As for the rack, no place to use ratchet straps to pick it up?

[ArdWrknTrk]

Progress, Jim!

As for the rack, no place to use ratchet straps to pick it up?

This shade tree mechanic has no shade tree.....

I need to get everything out of the truck to remove the drop-in bed liner.

Then I can unbolt the rack from the bed rails.

While I have it off I need to see about shimming the bed, so it lines up with the cab, now that the cab has poly bushings.

[Gary Lewis]

This shade tree mechanic has no shade tree.....

I need to get everything out of the truck to remove the drop-in bed liner.

Then I can unbolt the rack from the bed rails.

While I have it off I need to see about shimming the bed, so it lines up with the cab, now that the cab has poly bushings.

Ahhhh! Ok.

As for removing the drop-in bed liner, I certainly understand that. Yesterday I PB Blasted the bolts and nuts holding the 5th-wheel hitch bracket in Big Blue's bed so I can get the bed liner out. But the tool box has to come out as well before the liner comes out.

And while I was at it I lubed the ends of the bolts holding the hip-busting camper tie downs to the front panel of the bed. With the tool box out I can reach the bolt heads and finally remove those blasted things.

[ArdWrknTrk]

Ahhhh! Ok.

As for removing the drop-in bed liner, I certainly understand that. Yesterday I PB Blasted the bolts and nuts holding the 5th-wheel hitch bracket in Big Blue's bed so I can get the bed liner out. But the tool box has to come out as well before the liner comes out.

And while I was at it I lubed the ends of the bolts holding the hip-busting camper tie downs to the front panel of the bed. With the tool box out I can reach the bolt heads and finally remove those blasted things.

I have a torch!

Things can't be seized when they're molten.

[Gary Lewis]

I have a torch!

Things can't be seized when they're molten.

Would work fine for the bolts on the 5th-wheel bracket, but I'd rather not point a torch between the cab and the bed to get the camper tie downs off.

I'm hoping that the carriage heads for the 5th-wheel bracket bolts will hold and the nuts will come right off with an impact.