How much HP/TQ am I making?
 

I'm slowing setting up my 02 24v 1 ton dually for towing. I'd love further advice, if any available, and an estimate of how much HP/Tq I'm making with the current mods:

Edge Evo Tuner set on Heavy Trailer
AFE Cold air intake
4" Exhaust and Magnaflow Muffler
Fass DDRP
+ 50 HP Bosch RV275 injectors (Just installed today - nice improvement!)
Auto trans has been rebuilt with billet TQ Converter and Kevlar bands.

I've got a 3 piece exhaust manifold waiting to be installed

My goal is to set up for best towing ability on my 11k lb. fifth wheel. It pulls pretty darn good now, but with steep, long grades I have to keep my momentum/speed up or I'm done, having to pull the balance of the hill at 40 mph or so in a lower gear.

No doubt my 3.55:1 gears aren't best in this application, but after careful consideration running with OD off uphill puts me at an effective gear ratio of about 4.56:1 if I remember my calculations right. This gives me a pretty powerful gear train for pullin' hills with OD off, as well as a great highway gear train with OD engaged, especially when empty.

Anyway....back to my original question: What estimate is available for HP/TQ with the mods that I've installed to date, including the exhaust manifold which I'll do soon?

Any other advice to improve towing ability and still keep it reliable?

Thanks!

The FASS, exhaust and air intake won't add very much if any, the trans will help but still takes a lot of hp to operate,

I'd say you gain 50 with the injectors and about 90 with the Evo as far as hp goes...so with a stock 235 + 50+ 90 you are probably right around 375 hp/800 trq.

A dyno run will give you a true reading.

I agree with SIXSLUG. I would say you are around 375-395 H.P.

Is the HP for each mod additive?
 

Thanks for the replies...

I thought that I had read somewhere that the HP gains for each individual mod wasn't additive. That you couldn't stack the gain for the tuner on top of the gain for the injectors, for example.

I like the estimates however, but am hoping to understand better what I've gained from the installed mods.

The real test will be pullin' up some long, steep grades to see how it performs, and I'm anxious to do that soon...

Watch your egt's!

You're ahead of them on the exhaust mod and bigger injectors.

The 3 pc ex manifold will help out a stock turbo I have read so maybe some more there.

I agree that you don't get what's listed as far as adding hp because accessories eat up a lot of it as does an auto trans, however, a team of 400 horses hooked up to a 2500 would be a sight!!

Good advice....thanks
 

I'm always watchin' the EGT's. Even before the recent injector upgrade it's not difficult to get to 1200 degrees on a grade with the trailer.

I've also been told that the three piece manifold might help drop EGT's by 50 degrees or so, and that with the injector swap I might be able to drop the tune to a less aggressive setting which will also help....we'll see.

Keep us posted, I'm going to do rv275's soon.....

Doin' the injectors was a kick in the pants. It was an all day project, but can be done quicker. I was fortunate to have my brother in law help who's an ex heavy equipment/diesel mechanic. (Cats, Detroit, etc.) Knows his stuff and super meticulous. We found a pretty good 3-part tutorial on YouTube that walked us through it well.


We got hung up doin' research on whether or not to re-torque the head bolts while we were in there. Some recommend it, others are against it.

He felt uncomfortable with the idea not knowing the condition of the threads (lubed or dry) added to the uncertainty of disrupting the existing head bolt torque and overall condition. We left it alone.

I figure if I continue on the same path I'll be looking into a turbo mod and possibly an exhaust brake anyway. At that point I'll likely consider doing head studs given the added boost.

First things first though. I need a good opportunity to get it out and tow some hills....

Nice, I am skeptical about a re-torque also, until you hit higher power numbers...

The ARP studs are like a 600 buck hit, so save up!!

Yeah...

I'd like to know what makes that brand so special, and what alternatives are available.

There's only so much "magic" you can put into a set of studs...

Ha! My bad..... After a bit of a search it looks like the ARP studs might be the most competitive at about $425.00 -
best pricing that I could find.

I would recommend sticking with the "ARP Headstuds" when you are ready.
DO NOT go with "A-1 Headstuds" as they are NOT up to par with ARP and
there are some sets for our Dodge CTD CR Trucks still "floating around" on
the internet.

Sounds like good advice....thanks.

Any details on what was wrong with them/problems they caused? I wouldn't chance it with even a hint of doubt expressed, but find myself curious....

----------
Apparently they were not heat treating the studs properly and they were breaking off in various places sometimes without the owners even knowing
they had broke.:o I am not sure if they are even in business anymore but
"A-1 Headstuds" can still be found on the internet.

Yikes! Grateful for the heads-up! :thumbsup:

Update:
 

So I finally found the time to bolt the aftermarket exhaust manifold on. I did a bit of polishing to the internal surfaces with a cone-shaped stone grinding bit. Nothing too extensive, just enough to clean up any rough casting edges.

It took the better part of a day to do the job. I took my time and was pretty meticulous about it all. Removing the turbo completely makes for a whole lot of working space, and well worth the effort IMO.

The end result in terms of performance was much greater than I would have expected. Power delivery seems much smoother now, with a slightly different exhaust note. (I like it)

The really noticeable difference is in the power delivery. So much more power seems available in terms of acceleration (pull) with less throttle than before. When the TQ locks up, it just starts to fly....

I've not towed with it yet but am anxious to do so. I'll try to remember to post my impressions after I do.

Suffice it to say....the combo of injectors and the manifold was a very worthwhile upgrade, and certainly doable by most as a DIY project.

IMHO you are so far into the range of 4.10 gears it's not even funny....

and, with OD off the trans is at 1 to 1 ratio converter locked. How are you coming up with "effective 4.56"? Are you talking manual second and a lockup switch??

1st: 2.45
2nd: 1.45
3rd: 1.00
4th: 0.69

I don't understand the statement....

From what I can remember, the calculation took into consideration the transmission gears, the differential gears, and the tire size to get to "effective gear ratio".

I don't recall the calculations, but the end result (IICRC) had me at a higher numerical gear ratio (lower gearing) in 4th with TQ locked and overdrive off, than if I had 4:10 gears running in OD....

I'm saying even with your mods towing an 11K trailer the combo would live a happier life with a 4.10 rear gear.

My race trailer is probably tipping in at 9K + and with some of the grades in the desert sw, I wish I had my 4.10 gears back. I swapped them out as the truck was basically our "station wagon" for many years and it became much nicer to drive with the lower rpm. Now that we have multiple cars the truck is pretty much set on "tow duty" and with the addition of a larger trailer, I'm now wishing I had the 4.10 back.

you stated that you slow down to "40mph" on some grades.... what rpm are you turning? Thinking out loud that seems quite low so that's why I'm thinking 4.10 gears would get the job done in a better fashion. I know on the steeps my combo, as many do, is happy at 2200 rpm. good balance between maintaining power and keeping egt in check.

This is very useful perspective...thanks!

I'm considering 4:10's now. As I've said earlier in this thread, I love my tall gears on the hwy when not towing, but the truck is used primarily as my tow vehicle. I have no doubt it would do much better in any gear up a grade when towing if lower gears were installed.

My ONLY concern is the cab noise and my "mechanical sympathy" for the engine at 2200 rpm on the hwy. As you said, it's just more comfortable at lower rpms.

I have the advantage of having the help of my brother in law, a formally trained diesel/heavy truck mechanic. He thinks we can bust it out in a day. I don't care how long it takes, if I can do it for ~ $500 or less, it probably makes sense. However, before I do anything, I gotta tow with the new mods to be able to see what effect those have had.

I'm off for some internet shopping for gears.....

With my setup I am sitting at around 19000 lbs with my trailer with 3.45 and 315 tires and live in mountain style terrain. With a six speed its not bad and even better on flat land as you said 70 @ 1500 makes a quieter truck

I suspect that you have more going for you with all the mods you list, the closer ratio gear splits, and additional gears. Man would I love a six speed. Your taller tires offset that a bit though too...

Prior to J Body's discussion and perspective from someone who's experienced both ratios while pulling, I had pretty much concluded that my best set up is the 3:55's in service now, as I could run in 4th with OD locked out when pulling grades, and still have OD for the flats. After his description, once again I'm not so sure, and it sounds like I'd only have to get used to a bit more in-cab noise and less top end speed on the flats if I switched out to 4:10's...

I think that I had calculated with 4:10's an rpm at ~60 mph of 1900 to 2100 IIRC. While that's not terrible, it is a bunch more noise than at 1600 - 1700 rpm.