Had some good luck in the last 3 weeks and I suddenly have money for a Quad and I have a few questions.

   I have a fuel pressure gauge in the truck already so is there any real reason to get the fuel pressure sender for the Quad? 

  I have RV275 injectors and a stock HY35 with a spring on the waste gate and make about 28 psi max.

  Trans has a stock rebuild on it done about 25,000 miles ago.

  I'm not looking to make 500 hp or anything I just want 275-300 hp. 

  The most important thing right now is fuel mileage. I'm getting 12.5-12.75 right now.

  Is there a tune on here that anyone would recommend for my combo?

  Is there anything I need to do before installing the Quad?

  Can I just put the Quad in without hooking it up to a computer or does that have to be done before use?

  I do not plan on the wire tap at this time. If i do it in the future i will use a Stealth Plate.

  Thanks for any help and please feel free to give me any advice that may be helpful in getting this thing up and running.

  

Edited December 1, 20195 yr by Gregturley

You ought to be getting 16 to 18 mpg minimum on the highway. Someething else has to be going on. Mine got 18 off the lot. My 96 with a V10 got 12 mpg down the highway. Just wish I knew where to help.

 

That milage is about 50/50 highway and town. I'm open for suggestions on this. Forgot to add i have RV275 injectors too.

1 hour ago, Gregturley said:

That milage is about 50/50 highway and town. I'm open for suggestions on this. Forgot to add i have RV275 injectors too.

 

Depending on driving habits, idle time, weather, geography, etc, 13 mpg with 50/50 driving could be reasonable.

My buddy is getting me a MAP sensor today. $103 after tax for a Cummins. Best price i could find.

Last time I looked for Cummins MAP they were $175 or so. Last one I bought was from Oriellys for $90. Made by Standard in USA. Only lasted a year or so though, failed when VP failed. Lifetime warranty. Hopefully this one lasts.

On 1/8/2020 at 6:00 PM, kzimmer said:

Definitely a common part to fail. I've had two fail in probably 30,000 km or less. The first one that failed just wouldn't output anything, was always zero PSI. The second one also shorted the 5v supply and I lost my oil pressure reading. Cheap crap... I have no idea on what brands they were. 

F me... Two days after I type that, this morning I cooked another map sensor. WTF. -28°C morning, boosted it with my half ton to help it turn over faster to get it started. Possibly gelled a little, time to change filters. Plus I had it plugged in with a block heater timer, I think when it's this cold I need to bypass the timer and leave it plugged in all night. Sorry for the hijack. Why the hell would boosting my truck cook a map sensor and nothing else? My batteries wasn't even dead, they were just starting to get low from cranking. Maybe it was a coincidence. No more cheap *** rock auto sensors I guess. If anyone has a recommendation for a MAP sensor brand, I'm all ears. I'm assuming Cummins just buys a jobber and puts their name on the box. This truck is by far the shittiest winter vehicle I've ever owned. 

 

Just a thought, I didn't unplug the quad before I boosted the truck. Is the quad and/or its boost fooler somehow causing problems with the map sensor? Probably not, but it's an interesting thought.

 

Sorry for the thread derail @Gregturley

Edited January 10, 20205 yr by kzimmer
More info.

I went Cummins. Found them online for a little more after shipping but i got it in my hand today. $102.14 after employee discount and tax.

I have the service history on my truck and cannot find where it was ever changed.

22 hours ago, Gregturley said:

Not lifted, 265/75/16 tires 3.54 gear.

 

That wide tire will only give you roughly 16 MPG stock config max according to my fuel logs of the past. I dropped to 235/85 R16 for years and did much better because the 235's were almost 20 pounds a tire lighter. Now switched to the door label to 245/75 R16 and now gain more torque. I went from 31" tire down to 30" and the tire is still slightly light than the 265/75 R16. This last change of tires altered the final ratio to the ground from 3.55 to 3.69. Making the truck even quicker and producing more torque at the rear tires. Wider the tires the more rolling resistance. Hence why true racing vehicles have very narrow front tires to reduce rolling resistance. Rears have to be wide and light for traction and reduce rotational mass. 

 

22 hours ago, Gregturley said:

Drop it in neutral and it will roll easily.

 

What are your tire pressures? Typically most 235, 245 and 256's tires are 3,042 pounds at 80 PSI for capacity. Using my truck for weights which I just done last week. 

 

Tires -> Hankook ATm 24/76 R16 rated for 3,042 at 80 PSI

 

Front axle - 4400 pounds -> 4400 / 2 = 2200 / 3042 = 0.72 x 80 = 57.8 PSI Inflate the front

Rear axle - 2900 Pounds -> 2900 / 2 = 1450 / 3042 = 0.47 x 80 = 38.1 PSI Inflate the rear

 

This will get you the best tire wear, traction, and comfort in the truck. So like I typically just run the 60 Front and 40 rear being I may carry some weight some days. As for pressures for full 8,000 pound truck weight capacity is 60 PSI in all tires will cover 8,000 pound GVWR. If I'm going for comfort I would drop down to 55 PSI front and 35 PSI rear this also works good on soft surface like sand too. Loose materials require low pressures for better traction.

 

 

Edited January 10, 20205 yr by Mopar1973Man

I have run 265's on mine since new, they were option I chose, and instock condition got 18 mpg on the interstate. Rv275's and a tuner got me up to 19+. This is strictly interstae driving.

Interstate now I can tip 19 to 20 MPG with my winter tune 80 MPH @ 2,500 RPMs. Highway is 18 to 19 MPG with all the 6 and 7% grades I drive (55 to 65 MPH) and 4WD usage with snow.  

 

 

I run 55 front 45-50 rear. That economy tune is based off your 7x.010 injectors correct?

1 minute ago, Gregturley said:

I run 55 front 45-50 rear. That economy tune is based off your 7x.010 injectors correct?

 

Yup. The winter tune is rather retarded in timing being the cetane in the fuel up here is pretty high. Summer tune has lot of extra timing.

Put in the map sensor at lunch. Problem solved. Mechanical and Quad are now within 1-2psi from my quick blast across the parking lot. Quad saw 24psi today. Its never read above 13psi or so since i installed it.

 Old one was still 32mm which makes me really believe it had never been changed. Have 184xxx on it.

I notice a big drop in mpg when it gets below 40, also if I drive faster then 65 mpg drops too. Lately I've been getting around 16 mix driving. In summer I'll get close to 19. I can get over 20 in summer if I drive nice. Actually I got my quad fuel usage dialed in to almost exact amount when filling up and if I drive accordingly I can probably get closer to 23-24mpg I just don't have patience for it. 

I want 20 mpg but now I'd settle for 15. Just something better than 12 to 13, that sucks.

1 hour ago, Gregturley said:

I want 20 mpg but now I'd settle for 15. Just something better than 12 to 13, that sucks.

My 96 had a V 10 in it. It got 12 on the interstate and about 6 around town. That was 1 of 2 reasons I got rid of it. The second was # 10 piston was in the oil pan, never ran right after that.

Edited January 10, 20205 yr by dripley

After my ride home it looks like Quad is 2 psi lower than Autometer. 

7 hours ago, Gregturley said:

I want 20 mpg but now I'd settle for 15. Just something better than 12 to 13, that sucks.

I get 15 on interstate running 70mph, 10-11 towing any kinda of weight at 67mph. I could justify a Quad if I could get close to 20 mpg empty and 15 mpg towing.

3 hours ago, Gregturley said:

After my ride home it looks like Quad is 2 psi lower than Autometer. 

 

On the low end, high end, or all around? Either way it sounds reasonable to me. FYI, Cummins quoted me $225 CAD ($170 USD) for a MAP sensor today. Yuck.

@kzimmer seems to be all around. I'll keep watching it next few days to verify.

 Check online for the sensor. Cummins pn 4921505 for a 2001. I found it between $85-100 + shipping. By buddies employee discount just barely beat that plus i got it at 7am today.

 KLM Performance had it for $99.

@Blueox01 i really haven't started tuning it yet. Ran 1st tank on default tune, 2nd tank on a tune from here, now on 3rd tank and tweaked the tune a little.  Each tank is 2 weeks over the same route give or take a little. Haven't done a road trip to check highway mpg yet. Other than a lazy map sensor i haven't changed anything else. 

@Mopar1973Man @Me78569 will a map sensor affect fuel milage on the Cummins?

Edited January 11, 20205 yr by Gregturley