My thoughts from 275's to DD2's

[Big White Beast]

Sky....

Here's my tale. I have just the EZ and DD2's. I could make so much heat in my turbo (HY) that it turned yellow/brown. But the intercooler does work and I had plenty of power with no EGT problems. I went with the PDR35/14 and didn't notice any real gain in power (some but not worth the money). Spool up was a little slower but once up to speed it felt smoother in the power band. I decided to try a 12cm² to see if it would spoool quicker and it does. But I lost my apparent gains in the power band.



Either housing with the bigger turbo gained me about 1/2 MPG. In my opinion it's not just the air your pumping in but how quickly you can get it out also. IE:housing size.



Unfortunately there isn't a variable turbo yet that could be set up for normal driving and then follow the comp settings.



I guess what I'm saying is it would be best to set up your truck for what you drive most. A PDR35 would help with your DD2's but not in the low end. You would have more lag. It will really settle in nicely though once your in the power band. As you stated the 2's were a lot of money for minimal gain. I think you'll find that the turbo might be in that same arena.



P. M. or E-mail me and I'll give you my # and we can discuss it if you like,



Garrett

 

[abledog]

Originally posted by Sky





I do keep my rpms in the 2000 range. You have the 275's also. I am willing to bet if you went to dd2's you would lose milage. I just took a 400+ mile trip today with no trailer and got 16. 5 MPG where before I was gettting about 20-21. I am really bummed out. With as much driving I do (about 40k a year) I may go back to the 275's.

It looks like it would be worth the effort to put the 275's back in just to see if your milage goes up!

If you decide to keep the 275's, the DDll's should be easy to sell or trade.

Terry

 

[tragicwagon]

Just thought I would bring this back TTT and ask a question myself. Does everybody experience these results when changing from 275s to dd2s, or is this a rare equation? I do alot of towing and was thinking of installing dd2s, but if they are going to hurt low end grunt I wont. Maybe Ill go with 275s or dd3s,any advice?

 

[Sky]

Originally posted by tragicwagon

Just thought I would bring this back TTT and ask a question myself. Does everybody experience these results when changing from 275s to dd2s, or is this a rare equation? I do alot of towing and was thinking of installing dd2s, but if they are going to hurt low end grunt I wont. Maybe Ill go with 275s or dd3s,any advice?

If you tow heavy I would stick to 275's. If not I would not go less them dd3's. But they are a lot more money. If you have a box I would just do 275's. You will lose low end grunt. But from stock to dd2's you wont lose it. So you probly will feel a gain for sure.



I think If I was stock I would go with a comp box and 275's over just going to dd3's. This is what I would do.

 

[tragicwagon]

sky





Im not stock, I dont know for sure what the gains are with my mods, a guess would be in the 70 to 80hp range. where in the rpm range did the dd2s overrun the 275s? Ive never ridden in any other bombed trucks, but mine seems like a dog under 1800 rpm, I dont know if this is normal or if the ottomind dosent fuel at low rpm.



Does anybody out there tow with dd3s and a stock turbo? if so how are your egt's?

 

[Bob Wagner]

thanks alot Mike

My DD2 stocks are really on the slide now



Seeyou at Timberline

 

[HEYBOSS]

275's and comp rock

I just installed 275's and comp and I'll tell you couldn't be any happier. Just returned from 900 mile trip from IN. and in PA there are some pretty good hills for miles long, this thing just hauls. Believe it or not I was towing the 5er which empty weighs in at 9500lbs and I blew a Power Stroker pulling a pop up, Yes up hill and clocking 75-80mph I was totally amazed how this thing handled it, never expected to blow the doors of the power (now Choker) just pulling a pop up. By the way the comp was set at 1x3. highest Egts 1200

 

[SLightfoot]

I'm happy....

Well, I've considered upgrading my 275's to Stage II or III's in the past, but that notion has died down in me.



Not because of this thread, but because I tow a LOT and so far, I really don't need any more power. Actually, I know that with any more power, something else will break. I just upgraded the clutch, and it's time to call it enough.



I have the EZ and 275's and I honestly can say this is a rock solid combination. Tons of low end grunt, and solid midrange.



Personally, I don't care how fast it runs empty - I don't drag race. I tow our 5er- and I need to do it consistently without breaking something.



Someone else mentioned on here - Drive what suits YOUR needs best.



There seems to be a lot of different setups for these trucks, and some are awesome for drag racing but you couldn't tow anything to save your life (EGT issues, etc) and there are serious towing trucks that couldn't drag race worth a darn.



Whatever works best for you is the right setup.



Shawn

 

[KennyM]

I just replaced my stock injectors with a set of DD II's, I also have the DD UFM, but towing I turn it off. My trailer is in sig below and weighs no more than 10K. The difference is unbelievable when towing my trailer. Hills that I used to shift down to 4th I was only at half throttle in 5th with the DD II's. The EGT's pre turbo never went over 1000, and I think I would hit about 32 pounds of boost not real sure on that. This was WOT on the largest hill, going about 70mph and accelerating. I had my wife watching for smoke and none was detected. I give these injectors an A+. Just my $. 02. Ken

 

[Sky]

O yea from Stock injectors to DD2's is hands down better I agree. But for the money and performance towing with 275's is better IMO.



Hey Bob, SELL, SELL, SELL!!!



When is Timberline this year?

 

[Bob Wagner]

July 13th

 

[fj40charles]

I'm trying to understand how 275's can produce more low end torque than DD2's. Anyone have any ideas how this could be?



I went from DD1 to DD2's and have not noticed any lower torque number with DD2's.



TIA,



Charles

 

[Sky]

I was trying to figure that out too. Just curious if you noticed a big difference from dd1 to dd2's?

 

[fj40charles]

I noticed about 20 HP difference on the dyno.



Went from 276 HP to 298 HP in 6th gear. The HP numbers were a little higher in 5th gear.



Charles

 

[TxDieselKid]

Perfect Charles, just look at your dyno sheets and look at the torque line with the RPM on both, that should settle it, at least between DD1's, and DD'2, still not 275's.



Andrew

 

[Diesel Freak]

FWIW. . I went from 275's to DD3's



302 HP with 275's

358 HP with DD3's



Both at 2500 RPM

 

[fj40charles]

Andrew,



Good thinking... Why didn't I think of that... .



I made peak torque at 1800-1900 RPM on both DD1 and DD2.



Charles

 

[John Berger]

I agree with Shawn. I had to replace my clutch and enough is enough. I wanted to have more grunt when towing my trailer. And with a 12K 5'er in my future, I don't want to cause any more problems. Unloaded, my truck is quick enough to surprise quite a few people, but I don't want to go beyond that. To beat a dead horse: it really does come down to what you want to accomplish. As I've said in other posts: If you are towing heavy, the 275's and EZ are a tough combo to beat. Not only do you get more ummph for your buck, it's also not overkill on your driveline behind that Cummins.

 

[One Old Dog]

Injectors

I was going to by the 275's but I went with the dd2'S I have a va box and boost mod and I thought and what i have been told is that the dd2's were better. So I went went with the dd2's I pull 18,620 lbs and I do not need low end slag. with my set up do I need to sell the dd2's ( that have not been installed as of yet) and go with the 275's ? Please help the dd2's or some injectors or going in pdq. Thanks Joe

 

[Big P]

I'm pretty sure diesel dynamics has a dyno graph with the power output of 275's, dd1's, dd2's, and dd3's all on the same graph. www.dieseldynamics.com/popup/275hp.htm