I am a regular at the Corvette Forum, LS1Tech, Pro-Touring.com and Lateral-g.net. Just found this site which looks like it will now be added to my favorites, especially since my 05' LLY 2500HD should be here in a couple weeks. I am heavily involved with late model fuel injected performance but have not spent too much time working with performance diesels. This new truck is replacing my hopped up 02' Denali P/U mainly due to the need for more power and better economy, well...........really for more power!:ro)

From my early research it looks like I need to do the following but would appreciate more feedback. Sounds like the first thing to do is throw a shift kit into the Allison tranny. I hear that they need more line pressure, especially in 5th gear.

The intake is a no brainer and would probably yield improvements first over a 4" exhaust system. True? Who makes the best intake system? I personally like systems that ONLY pull air from outside and not from under the hood. Any options? As far as the exhaust is concerned I don't want it to sound like some of the Dodge's! If I want noise I'll fire up my C5!

Finally some sort of PCM calibration...I friend of mine has a 04' LLY with the Edge Attitude........ It is mounted in the roof console and looks pretty slick! The truck has mad power but it was all SOTP feel! I tend to like controls that are adjustable. What are my options??

Thanks

Howard

To correct your no brainer. I believe that research has shown no significant improvement of air flow by adding an aftermarket unit. Exhaust is a definite & as far as tuners, you have your personal preference. Congrats on your Duramax!:ro)

Reduce backpressure. Shoot more fuel in. Hang on.

Main problems to be addressed:

Trans clutches will only support about a 1/3 increase in RWHP if hot rodded.
Excessive EGT's will damage turbo.
Limited # of "Race" tunes for the LLY.
Engine has a 96mph limiter built in.

Good news:

Stock turbo will support twice the original HP.
Hard parts on the Allison are near bulletproof.
Hard parts on engine are very strong as well.
Transfer case and 4WD system will support big power.

IIWY, I'd start with an exhaust and a tuner, and see what difference it makes.

Thanks for the input!


My "no-brainer" comment was made for two reasons. 1) Easy enough mod with the lowest cost 2) how can in not help once the V/E is greatly improved by turning up the boost and free flowing exhaust.

Regarding the tranny mods; are the "bolt in" upgrades enough on a new tranny to handle some of the higher levels of power?? I see that ATS has kits from valve bodies to complete rebuilds. I don't feel like yanking the tranny quite yet and was hoping that the "shift kits" would greatly help.

Finally, who has solid RWHP/RWTQ #'s on a bone stock LLY???

Much like the LSx automotive gas engines, GM picked the "low hanging fruit" fairly effectively on intake air gains.

It's not that an aftermarket CAI doesn't gain flow, it does. But the at the stock performance level, nobody I've seen has posted a significant gain to justify the cost.

Doing the exhaust is fairly simple with hand tools, and will show a much larger gain/$$$.

Call Mike L. at Inglewood transmissions and ask him what he would suggest. He won't BS you or try to sell you something that won't help you. You have 2 major problems: the trans clutch pack that performs the 4-5 shift (C1?) and the torque convertor lockup clutch. Normal min upgrade is usually a beefer TC and a Transgo shift kit.

The Allison is very strong, but they designed the clutches in it for smooth operation at 600ft/lb. When you start making 800, it requires more ummpphh than the existing plates.

You should really try an exh and a 50-85HP tune and see if that's what you are looking for first. This will allow you to smoke a Silverado SS. Unlike car mods, most diesel tunes are a MINIMUM of the rated RWHP gain. Think of what gain you see in a car when you increase the HP by 33%. You will get even more gain in the LLY. My truck ran 17.6 when new, and dropped to 15.5 with just a "50HP TTS Tow Tune" and removing the cat. No other changes. With a "100HP" tune it drop to the mid 14's.

When you add 100hp or more in order to get the full benefit trans upgrades are necessary.Like McRats post if your happy with the lower power setting the allision will do just fine. Some are trying to change Programing (Programing only, this has left some owners With additional future cost and Problems) Hardware changes are more important.Example:If you lockup the TC to soon The RPM"s drop and EGT"s clime and engine loses Hp,If the TQ is more than the TC clutch can handle it will slip. All Three GM/FORD/DC have safety features to Prevent This. If you try to override these safety measures Damage will result.This is just one possible scenario.

and was hoping that the "shift kits" would greatly help.

Finally, who has solid RWHP/RWTQ #'s on a bone stock LLY???
241 HP 503 TQ On a Mustang Dyno
Pete

McRat,


Thanks for your opinion. I own a late model performance shop we are very well versed in the aftermarket world. I understand that the intake gains are minimal on a stocker but if I'm dropping a few thousand on upgrades I mind as well get it out of the way. I would have to think that at 500+ power levels an intake system would help.

I spoke to the guys at ATS today about there Stage 1 tranny kit. He seemed to of indicated that the Stage 1 (co-pilot) kit would be fine with the Edge Attitude w/Juice unit. What do you guys think?? This truck is for most daily use, towing a car trailer and to beat up on ricers when the opportunity exists. If the truck where to see high towing loads and/or racing, I would yank the tranny for a complete upgrade. I like the concept behind the Edge unit to be able to control power levels on demand. Any cons with this??

As far as exhaust systems are concerned; I want SS and really need to keep the cats as NY is starting to sniff test vehicles. ATS has a 4" with 5" outlets....anyone use it??

Thanks again for everyones input!

500rwhp would probably only be doable with drugs using existing tunes for the LLY. We are currently hovering at low 400's with on-the-shelf "#2 Only" components.

The LLY Edge has mixed results. Some swear by it, some swear at it. Their customer service is excellent, but at least on my truck, problems with how it handles the turbo during shifts keep it from producing good ET's.

If someone asked me what was the best "hotrod" tune on the market right now for the LLY that is on the shelf today, I'd have to say the LLY Predator. The TTS level 2 for LLY's is slightly better in all aspects of performance and drivibility, but it has not been officially released. It's my favorite daily driver tune.

I Don"t know who you talk to at ATS. Did you mention any concerns about the TC, We would not do a upgrade without the TC.It adds to the cost but you will not be disappointed. Stage 2.

The 500 that I stated was for FWHP NOT Rear wheel. I guess I'm not used to the "pre-programmed" tunes as I am very well versed in LS1 Edit and DFI programming. Every vehicle requires different programming which explains why some guys have good luck and some don't. I can tell you that GM's programming blows! Out of 8 ZO6's I tuned this year 5 where so fat that they picked up 20-20 RWHP on a stock car! Boosted applications are typically worse with consistency. Just out of curiosity, does anyone make software for custom programming?

What would guys recommend for a tranny package with the following mods;

4" Exhaust
Someones programmer (100 HP/250 TQ??)
Intake System

I told the guy at ATS what I was planning to do and he said nothing about the TC. Who's got the best converter and which kit would work well with the above mods? I assume the package I am looking for is relatively average??

The stock air box needs no modification...in fact there has been problems with aftermarket intakes on lly's actually decreasing power. Start with a 4in front pipe back catless exhaust, a predator tuner and a tranny upgrade. The tranny issue is a sensitive subject here...but while the tranny is a part a tc, some clutches and a shift kit is really the way to go no matter how you slice it. I really like my suncoast lvl3....$3500 dollars installed and will handle quit eaisly everything you are asking about. Don't forget a boost and pyrometer gauge package to keep an eye on things.

The 500 that I stated was for FWHP NOT Rear wheel. I guess I'm not used to the "pre-programmed" tunes as I am very well versed in LS1 Edit and DFI programming. Every vehicle requires different programming which explains why some guys have good luck and some don't. I can tell you that GM's programming blows! Out of 8 ZO6's I tuned this year 5 where so fat that they picked up 20-20 RWHP on a stock car! Boosted applications are typically worse with consistency. Just out of curiosity, does anyone make software for custom programming?

What would guys recommend for a tranny package with the following mods;

4" Exhaust
Someones programmer (100 HP/250 TQ??)
Intake System

I told the guy at ATS what I was planning to do and he said nothing about the TC. Who's got the best converter and which kit would work well with the above mods? I assume the package I am looking for is relatively average??

Nobody is making a LS1Edit style gadget for Diesels yet. The "pre-packaged tuners" for the diesels are nothing like the gas units. They actually work, and even the worst of them is better than the average gas tuner.

If you stick to an 85hp tune, you should not have to worry too much. You will truly be suprised how good even a 50HP tune works in these trucks. But you said 100.

I would go with a torque convertor and a Transgo if 100HP is all you are going to run. But what are you going to do when they come out with a 200HP tuner that will kill your trans clutch packs? Well, I guess you could just avoid the temptation and just not buy one.

I guess the trans question is really: How strong is your will power? :muahaha:

Nobody is making a LS1Edit style gadget for Diesels yet. The "pre-packaged tuners" for the diesels are nothing like the gas units. They actually work, and even the worst of them is better than the average gas tuner.

If you stick to an 85hp tune, you should not have to worry too much. You will truly be suprised how good even a 50HP tune works in these trucks. But you said 100.

I would go with a torque convertor and a Transgo if 100HP is all you are going to run. But what are you going to do when they come out with a 200HP tuner that will kill your trans clutch packs? Well, I guess you could just avoid the temptation and just not buy one.

I guess the trans question is really: How strong is your will power? :muahaha:
Well stated! I guess at this point since I haven't even taken delivery yet I am going to start out with a 50-85 HP bump, exhaust and a shift improver kit. I would like to put some miles on the truck like that and then pull the tranny,beef it up and step up the power. I actually enjoy the stages of mods and this will keep the interest in the truck!

Who's tran kit should I go with for now prior to a complete build and TC??

I'll give the Predator a try and then step up to a converter.

IMO...

Get the Predator and a exhaust, run it on 65 or 85 for awhile. Then contemplate how you are going to use your truck. If this amount of power is adequate, other than a pyrometer for towing, you are done.

If you find what you REALLY wanted to do was humiliate Lightnings and SRT-10's, drag race it, and pull 50,000lb sleds in the dirt, then do the whole trans and do it right. By then, some bigger tunes should be available, and you will have the muscle to support 'em.

What is the difference between a 12 second Lightning/SRT-10 and a bombed Duramax? The Duramax is in front of the trailer, not on it. ;)

IMO...

Get the Predator and a exhaust, run it on 65 or 85 for awhile. Then contemplate how you are going to use your truck. If this amount of power is adequate, other than a pyrometer for towing, you are done.

If you find what you REALLY wanted to do was humiliate Lightnings and SRT-10's, drag race it, and pull 50,000lb sleds in the dirt, then do the whole trans and do it right. By then, some bigger tunes should be available, and you will have the muscle to support 'em.

What is the difference between a 12 second Lightning/SRT-10 and a bombed Duramax? The Duramax is in front of the trailer, not on it. ;)
Sounds like a good start and will give me some time to soak up the diesel performance scene some more. !

Dentonate,

Not to steer you away from the information given, cause its all true and knowledgable. But for added benefit you asked about custom tunes.

I do not know where you are located, but in terms of custom tunes Verdone Performance in Scottsdale Arizona (Joseph Verdone) knows the in and outs of programing GM. Being that you are a vette person (like myself) - he has also does quite an extensive custom tune on the LSx. Last I recall hes pushing 600 hp on stock injectors on his Z06 (not common for LS1 edit). He does all sorts of programming for GM vehicles (Duramax,Vortec,LSx). He's doing my programming on the Duramax shortly and I'll come back with Dyno results shortly after.

Give him a hollar even to learn something from him..full of knowledge. Shoot me a P.M if you have questions, I just hate to elaborate in the fourm if not needed.

Verdone Performance @ (480) 423-9939 - make sure you ask for Joseph


- Mark

Mark, thanks for the info! I will definately give him a call. From his area code he looks like he might be near some guys I deal with at Extreme Performance. They deal with LSX cars as well.


Sent you a PM!