Engine Modifications

[homer3]

I have a few questions, any answers or suggestion would be welcomed;

2006 Durmax

1. Aftermarket Air Intake - Cold Intake modifications such as K&N. Has anyone done this? If so do you see any noticeable improvements in engine performance?

2. Aftermarket exhaust Brake - My local dealer ship really did not think I would get much out of this for the cost, since I already have the Allison Transmission and the built-in breaking capabilities when running in Tow Haul mode?

3. What would be a good Brake Controller. I have not confirmed but after last trip I have a feeling my controller is going out. I have to run diagnostics on current one. Did not seem to be operating correctly when coming home after last trip. Any suggestions on brand and model.

[GMcKenzie]

Originally Posted by homer3

I have a few questions, any answers or suggestion would be welcomed;

2006 Durmax

1. Aftermarket Air Intake - Cold Intake modifications such as K&N. Has anyone done this? If so do you see any noticeable improvements in engine performance?

There was a very long article on one of the diesel forums where someone had independent tests on air filters. K&N was the worst at filtering. AC Delco the best. Both flowed more than enough for normal towing needs. Unless you've opened up your exhaust, gone to bigger injectors etc., you will see no gains (but it may sound better with a CAI).

2. Aftermarket exhaust Brake - My local dealer ship really did not think I would get much out of this for the cost, since I already have the Allison Transmission and the built-in breaking capabilities when running in Tow Haul mode?

I kinda agree with this. Unless you have long downhills stretches, your current setup should be good enough. I had an 01 Duramax, traded it in last year and it was still on original brake pads.

3. What would be a good Brake Controller. I have not confirmed but after last trip I have a feeling my controller is going out. I have to run diagnostics on current one. Did not seem to be operating correctly when coming home after last trip. Any suggestions on brand and model.

Prodigy P3.

Modifications I would make to a diesel if I bought one again are:

Pyrometer. Absolute must have for a diesel.

Chip or tune. Lots of guys can do a (crap I forget the name of it) tune. I had an Edge chip and could turn it up enough to hurt the tranny. I didn't, but it came with warnings. The motor can be easily tuned to put out more power than the tranny can take.

Exhaust. 3 inch, EGR delete and maybe a cat delete if your state doesn't test for it. My 01 had next to nothing for pollution control. Did not have a Cat from the factory.

There are a couple of good Duramax forums out there where you can get a better answer. Just don't get sucked in by the guys who do tractor pulls unless you want an empty wallet and bigger mortgage. I've deleted my links to them since I went back to gas.

[bsmith0404]

Originally Posted by GMcKenzie

There was a very long article on one of the diesel forums where someone had independent tests on air filters. K&N was the worst at filtering. AC Delco the best. Both flowed more than enough for normal towing needs. Unless you've opened up your exhaust, gone to bigger injectors etc., you will see no gains (but it may sound better with a CAI).

This is exactly right. The AC Delco is the best filter for your truck. CAI will flow better, but the ACD gives more than enough air and keeps the bad stuff out better than anything else.

As for the exhaust brake, it depends on where you normally tow. My dad has an 06 duramax, I followed him through a town with a lot of hills one time, he was always on the brake, I never touched mine. Out on the open road, it's not that big of a deal if you build up a little extra speed, different story going through town.

[Richard Noble]

I have an '07 Duramax dually. The main problem I've had (and I think the '06's had) was a tendency to over heat. '07 had a few things that were changed to prevent engine heat from getting into the stock air intake. I had a heat extracting hood installed (after hail forced me to) that has really helped. It was built to be able to use air from the front of the hood flowing directly into an after market air intake but I can't find one of those that will fit and it has louvers that allow engine heat to flow up and out. It has reduced the heat problem.

I've had Fords with exhaust brakes but I have not seen the need for one with the manual control over the tranny in the Chevy.

I will never again put a chip in any truck I own. They are expensive, don't seem to work that well (for towing), and can destroy a tranny.

[Desert185]

When I had a '94 Cummins 12 valve, the Turbo Diesel Register forum did some tests and found that the AFE cold air intake gained horspower on a dyno. Since it had no electronic injection I installed a torque plate in the injection and a boost orifice for the wastegate. The stock 400# of torque was enemic. The power "package" increased torque quite a bit and mileage went up a couple. I would do it again, and did with my current Cummins.

I now have a 24 valve Cummins with a cold air intake, a 4" mandrel bent turbo back exhaust, a PacBrake engine brake and a Smarty tuner. I did change out the air filter to an R2C Performance filter, which flows and filters incredibly well. I have one on my Polaris RZR and there is absolutely no dust downstream of the filter element. I actually called them and they made a Black Hex filter dimensioned to my requirements. Check them out...

See: www.r2cperformance.com

All I did resulted in more power and better mileage within the limits of my drivetrain's capability. If done right, you'll like the mods.

My experience may be different with your Duramax, so I would consult a forum for your wants and needs. You want to ensure that the torque output doesn't toast your auto or clutch. The older Allisons were torque limited to 700#. Do your homework before you buy.

Exhaust brake. Get one. Every diesel puller should have one, whether stick or auto.

I have a Prodigy P2 and would only buy a Prodigy P2 or P3. I tow different trailers with different weight capacities. The P2 is adjustable for towing weight. Great controller.

I also think it is important to know EGT, lift pump fuel pressure (at least on the Cummins) and boost pressure. Some tuners indicate those and some don't. More homework.

I have A-pillar gauges and my tuner plugs into the OBD port for programming then disconnects. It also allows a reset back to stock with no telltale evidence of a tune in the event one lives in states like Kalifornia where one must undergo a smog check. Make sure you have the latest software update from Chevrolet before the tuner "tunes" because it memorizes the stock tune settings of your particular ECU. I would get the latest OEM software update regardless of whether I "tuned" my ride or not. The software can do things that reduces overheating issues for example, so updates are generally good things. Chrysler charges $100 for the update, BTW. More homework.

[BOWWOW]

There is an engine brake that I had on my 2007.5 Duramax that worked very well.
It was a Banks SpeedBrake. It works by opening and closing the variable vanes in the turbo. It held speeds down on 7% grades towing 16K.
It was amazing with the Allison 6 speed.
Banks also make a tuner kit that includes the SpeedBrake. I think it's called the Sixgun ?
I had a AFE II airbox with torque tube.
EGR delete also.

[denverpilot]

Other folks have covered instrumentation, but no one mentioned transmission temp. Besides pyrometer, boost, fuel, I also want to see how hot the trans is running.

Happy towing.

[Desert185]

Originally Posted by denverpilot

Other folks have covered instrumentation, but no one mentioned transmission temp. Besides pyrometer, boost, fuel, I also want to see how hot the trans is running.

Happy towing.

I believe his year Duramax has OEM trans temp, but you make a good point.

I added Fast coolers to my 6-speed stick and don't worry about the temp.

[denverpilot]

Originally Posted by Desert185

I believe his year Duramax has OEM trans temp, but you make a good point.



I added Fast coolers to my 6-speed stick and don't worry about the temp.

I have an oversized thing with fins (but not the fast coolers) and I've seen +150 on a hot day and a headwind. Don't like seeing that, so I get out of it or take a break for a while if the OAT will be dropping soon (sundown or precip ahead). I really wish my truck had 3.73s and not 4.10 in the rear end. It makes me want to tow in 6th which is always a massive heat builder in the unmodified NV5600. When/if it ever dies, it'll be rebuilt with drilled passages to cool the rear gears better, the one thing that transmission has always had problems with.

[Desert185]

Adding one more quart than Chrysler (used to) recommend saves the transmission. 150dF on an NV5600 manual transmission with synthetic oil a quart over shouldn't be an issue, especially in 5th gear (direct).

The Fast coolers lower temps 30dF, according to those that have a temp sender.

[denverpilot]

Originally Posted by Desert185

Adding one more quart than Chrysler (used to) recommend saves the transmission. 150dF on an NV5600 manual transmission with synthetic oil a quart over shouldn't be an issue, especially in 5th gear (direct).



The Fast coolers lower temps 30dF, according to those that have a temp sender.

Understand. Already have good quality synthetic and overfill. (Pretty sure the shop guy is an Amzoil freak so he probably used that. I'd have to look back at the paperwork in the filing cabinet.)

The issue really is that it peaked at about 180F which I didn't like at all. Want to change fluid and see if it's making any metal.

150F is pretty common on this particular specific transmission if I believe the sensor, which is another question -- is it accurate -- and we'll have to do some work to check that. (I didn't install it, and neither did my custom diesel shop guy. We're suspicious but it does read correctly cold.)

Guess it wouldn't be a bad time to put the Fast coolers on it if we're going to drain it and look for metal anyway... I wouldn't mind seeing it run 30 cooler!

[texas-traveler]

Does anyone have first hand experience with the Breathe Easy filters from SB Filters? presently running a K&N intake filter
Recently had the dpf and egr deleted. so far a lot more power and better mpg

[bobbecky]

180 to 230 degrees should not be a problem for the Allison transmission. I converted to the Allison Transynd fluid and find the tranny shifts better and this fluid holds up much better under high loads and temperatures. This is a link that discusses Allison transmission temps. http://dmaxstore.com/products/?route...product_id=543