Difference in RV275's & DD1's?

[JyRO]

Howdy!



I know some of you guys know this sort of stuff up, down, left, & right. But humor me here. Plus its probably talked about day in, day out. Sorry for asking again.



I'm familiar with 275's, I think I remember somebody saying DD1's were 275's that were matched. Then again, I think I heard that DD1's were extrude honed . I'm familiar with extrude honing too, I just don't know the details on DD1's.



Heck, if you guys don't mind, what's the difference between DD1's and DD2's? Thanks!



- JyRO

 

[GiesJ]

JyRO-

I'm sure someone will correct me if I am wrong, but 275's give about a 40 horse gain, DD stage I = 60 and Stage II =80. My buddy AZCUMMINS dynoed at 305 horse with an EZ and DDII's if that helps. Good luck!

J

 

[kiwi bird]

Here's a Diesel Dynamics dyno run.



Click Here

 

[HC]

Most I've e-mailed on this topic report better mpg with RV275's, but considerably more power with DDII's. If you want a "little" more power, and mpg that will help pay for the cost (over about 100k miles), go with RV275's. If you're heading down the performance road and not expecting a $$ payback, the majority will point to DDII's or higher. (I've tried only the RV275's) (so far)

 

[Barry]

Thanx Kiwi, that's a real eye opener. I think DD1's for towing with the stock part #'s will work for me. I have a new set of 275's still in the box. Why do the 275's get better fuel mileage than the stock ones do and how much diff is there between 275's and DD1's in fuel mileage??

 

[JyRO]

Thanks Barry...

Barry,



That's a lot of what I'm asking, what's the difference between 275's and DD1's. As far as better fuel economy, what I've heard is that the 275's have a better spray pattern than stock injectors. Yet if you were deep in the pedal a lot, the 275's would reduce fuel mileage because they have the potential to flow more fuel/make more power. That's how I understand it.



I still want to know what DD1's are. I've heard DD1's are stock injectors that have been extrude honed, but I don't know if that's really true.



Kiwi's link did answer one of my questions though. I didn't know if DD1's made more or the same power as 275's. Now I know that DD1's make more power.



- JyRO

 

[nickleinonen]

from that DD dyno graph, it looks like the dd2 injectors are a good set. . they have they same bottom end as the factory, but get stronger going up the rpm. .



from reading further down on the page...

True Torque II Stage 1 injectors also carry the same part number as your stock injector. so they look like modified factory spec injectors

 

[JyRO]

I didn't notice...

Great point Nick - I suppose they are stock injectors that have been extrude honed!



- JyRO

 

[raf2000]

I have run 275's for about 90K, just put in an EZ (DDTT) and will replace my 275's with DD1's in about 9K more miles. I don't expect anything much, kinda want to compare and figured when I get the freekin valve cover off again I'm changing SOMETHING! I will advise the difference, if any. IMHO. .

 

[PRout]

Ive posted this before, but hate to see someone else make the same mistake I did.



Go with at least DD2's, or you may not be satisfied.



I decided on only going with 1's due to having a VA which will make more smoke than an EZ w/ injectors. The 1's run very well, good response & smooth idle.



But, they are kind of a teaser, and make you realize you want more. Its hard to justify spending the money just to go up one step on injectors, so Id recommend if youre thinking of going w/ 1's, get the 2's in the first place and be done with it. With as many positive comments they have gotten from people that tow, you cant go wrong.

 

[Steve Campbell]

Hindsight being 20/20...

I agree with Shortshift

 

[WadePatton]

Well, I've always thought that I'd do the 275's first and DDIII's later with a turbo upgrade.



But for $200 it seems more and more plausible to start with DDII's.



I'll be putting a Comp on at the same time as the injector upgrade.



Any chance in heck I'll be able to keep the stock clutch alive for a while?

 

[Idaho CTD]

Wade,

I have a '02 etc with stage 3's and a comp box. The clutch will handle the injectors easily (they went in at 400 miles). If I run with the comp over level 2-3 then it will slip the clutch easily. So I would say as long as you dont go over level 1 and maybe even 2 with the box it will last a while. Invariably you'll have to put one in though. My SBC FE goes in on thursday.



Nathan

 

[jimk]

275 injectors

Because of the larger holes the injectors spray fuel into the cylinder quicker, (advanced) and that is the reason for the increased mileage, or that is what I have been told. lol Jim

 

[fj40charles]

I agree. Definitely go with DD2 and don't look back. It will cost your more money to buy 275's or DD1's and end up DD2's.



I hear DD1's are made from stock injectors. DD2's and Dd'3 are

made from 275 injectors. Someone correct me if I'm wrong.



Charles

 

[Steve Campbell]

Lots of opinions here...

I started out with DD1's and now wish I had ordered DD2's.

 

[John Berger]

I'm running 275's and I had not noticed a mileage increase, however, my clutch started going when I put the injectors in. The EZ had already been installed when I did the injectors. When I got the SBC clutch I picked up . 4 to 1. 3 mpg when towing my TT, running between 62 and 67 mph. I didn't have much of a baseline to go with, but my mileage on the compass increased as well. It comes down to how you drive I guess. DD2's are tempting, but my setup runs pretty well right now. I need to tow the 5ver through hillier(sic) areas than I see in South Georgia. If I had it to do over, I probably would have went with DD2's or the Bully Dogs.

 

[JyRO]

Slipping the clutch...

John,



Do you mean that you were running just an EZ, then added 275's and are now able to slip your clutch?



If so, that's a bit scary for me. That's basically what I'm running, and I decided not to go any bigger than 275's (from the git-go) because I didn't want to run into the problem of slipping the clutch. At least not for a while. And figgerd 275's and an EZ would be enough power for me (towing), which it is.



Mine hasn't slipped the clutch yet. Maybe your 4. 10's actually aid in putting pressure on the clutch. I'm not sure. Also, when towing my 9,500 lb. camper, I make sure I have the clutch fully engaged before I let the big dog eat.



Let me know if you are indeed slipping your clutch with 275's and an EZ, how hard you run yours, and how many miles you've got on your truck. Thanks.



- JyRO

 

[RobG]

I thought I'd mention in passing that I'm pulling my DD1's (which have factory part numbers matching to an automatic-equipped truck) out this week and will be posting them for sale. I'm going back to DD3's because with my setup (HX-40), they work better for me.



Rob

 

[Oxjockey]

Originally posted by RobG

I thought I'd mention in passing that I'm pulling my DD1's (which have factory part numbers matching to an automatic-equipped truck) out this week and will be posting them for sale. I'm going back to DD3's because with my setup (HX-40), they work better for me.



Rob

Hmmmm. We know that the ETCs have larger injectors, and these have the same part numbers as the ETCs...



Hmmmm.







Bryan