What effect does changing turbine size make?

[MoparToYou]

I have a 3500 QC 4x4 with the H. O. motor on the way, with an expected delivery date roughly six weeks away. After the first few oil changes I would like to boost performance to the limits of the stock clutch (700 ft. lbs. torque).



After reviewing the available options these last few months, I have come to believe that Diesel Dynamics puts together a pretty decent package. However, most of their performance packages for the ETH motor include a 16 cm2 turbine housing. Which brings up my question.



What effect will changing the turbine housing size from 10 cm2 to 16 cm2 have on my truck? Some people here are adamant that increasing the turbine size is not needed, yet all but the mildest stage that Diesel Dynamics sells for the ETH motor includes the larger turbine housing. So do I need to change the turbine housing? Why? What effect will it have on the truck if I change the turbine housing to 16 cm2? And what will be the effect on the truck if I choose to keep the 10 cm2 housing, but get all the rest of the mods for the stage I am considering?



Right now I am thinking of going with the Stage II ETH Pro package, which can be seen here



Thanks in advance for all the help.



MoparToYou.

 

[Bigsaint]

First off, WELCOME!!!! Next, gotta love someone who is planning on BOMBing his rig 6 weeks before delivery, reminds me of a guy I used to know .



The HX35 that will come on your ETH has a 12cm housing, not 10, I believe. Going up to a larger housing will significantly increase your lag time, i. e. , the time it takes for the turbo to spool up, without the benefit of more fuel. You can add fuel in three ways...

1) Add on fueling box such as the EDge EZ, the DD box or larger, such as the Edge Pro-comp or TST adjustable, to name a few.

2) Larger injectors.

3)Combo of the above.



A combo of larger injectors and a box will equal you looking for a new clutch sooner or later, most likely sooner, especially with the ETH OEM POS clutch. There is now way the OEM clutch will hold 700 ft. lbs. of torque, at least not for long.



Here's what I did with my ETH when new... I ran it stock for 2000 miles and got used to the stock power, which, believe me, is pretty darn good. I also installed gauges, pyro pre-turbo, boost and oil temp. , within the 2nd week of ownership, to help to establish a stock baseline. If I where to do it over again, I'd loose the oil temp gauge and replace same with a fuel pressure gauge a. s. a. p. , you have probably read some of the posts on lift pump issues, they are no where extinct as of now. Mandatory equipment, the FP gauge, especially if you are planning on BOMBing. Anyway, after my first oil change I added the Edge EZ box, everything else remained stock. I've kinda beaten this one to death, but I can't say enough for the EZ alone with an otherwise stock ETH. Egt's went DOWN and the power came UP!!!

Since then, yeah, I've added a few more goodies, read the sig. line below, but I'm really sick and just trying to beat 400HP @ the wheels now.



Try the new truck out stock first. Get some miles and gauges in, then try a low level box such as the Edge EZ or DD equal. If that's not enough for you, then replace the stock clutch with a better substitute, you have a few good choices now, such as the McLeod, Joe D's modified Sachs and the newest entry, the SouthBend Con Fe, which alot of members really seem to like. After the new clutch is in, then BOMB the daylights out of it with fuel line upgrades, banjo bolt upgrades or better yet, loose them altogether and replace with aeroquip fittings, showerhead size injectors, a bigger turbo, etc.



Bottom line is that you should start out slow with the BOMBing craze, things may/will break if you don't do it right, and that can be real hard to explain to your spouse, if you have one, when the rig is 1 month old and $40,000. 00. Just my $0. 02.



Scott W.

 

[Bigsaint]

Got alittle carried away and forgot to reply to your entire question... the larger turbo housings will allow for lower egt's, if applied correctly.



Scott W.

 

[DAWG-1]

Hi MoparToYou,

First I would like to say Welcome. Second I spoke with Piers today about turbos today. With his Hybrid turbo on a H. O. (what I drive) he recomended not to go larger then a 14cm2 on my truck with 4" exhaust, DDII injectors and an Edge EZ. Otherwise it would have too much lag, also the 12cm2 (stock) would work fine. I will opt for a 14cm2, so I can keep the stock turbo as a spare unit. Good luck on your new truck. Mine is not even close to complete.

 

[Powder Extreme]

Welcome to the TDR!!!



Here's my findings:

The larger turbo housing will lower EGT's and will cause extra lag. I went from the stock 12 to a 14 wastegated, quite abit lower temps, little more lag, then I went to a non wastegated 16, little lower temps, quite abit more lag. It seems to me that the 14 is probably the best balance, I'm considering putting mine back on until I can afford to buy Pier's new turbo.



High EGT temps will be your biggest nightmare with the new truck, I think any of us that have more than slightly modified ETH's have had problems.



BTW The stock clutch WILL NOT hold 700 lb ft of torque. My truck was around 275hp 675tq when I started slipping the stock clutch easily in 5th or 6th empty, replaced it before I did any towing at that power level, but I'm sure it wouldn't have been pretty.



Jerry

 

[n7gxz]

Welcome MoparToYou,



Sorry I don't have anything to say about the turbo size but I do have the HO engine and I can tell you that the stock clutch will not hold the power that you're talking about adding. I started out with 275 injectors, a PS boost module, 4" exhaust, and upgraded fuel lines. The clutch was holding at this level but I think it would slip a little from time to time. I added a VA CPC and I could slip the clutch almost at will, it was not problem slipping it in 4th, 5th, and 6th. Needless to say I have unplugged the VA for now. I have a Southbend Con FE that I will be installing in a couple of weeks and then the VA will get plugged back in and the fun will begin again.



Good luck with the new truck.



Kevin

 

[MoparToYou]

Thanks for all the responses everyone. Looks like I'll have to scale down my plans a bit if I want my stock clutch to survive very long. I'm not sure I want to be replacing the clutch on a brand new (not even built yet ) truck.



If I scale down my plans to just the Stage I ETH Pro (+100 HP, +200 ft lb), I wouldn't need to change the turbine housing either, which is something else I'm not sure I want to do.



MoparToYou.

 

[DHatfield]

MoparToYou, I have the Stage I ETH Pro as I have the DD1's and the EZ on my truck. My clutch doesn't slip and it definately has a lot more power than stock.