IDI's in Medium Duty Apps

[1320Cummins]

I think 1800 stall would be the ticket. I have a VERY tight converter in my 02 and its tough getting my 8500+lb TT off the line in a decent amount of time with out causing a traffic stopping blackout. The motor has plenty of grunt to get rolling its just waiting for the top turbo to spool and control the sloppy injectors is annoying. Same spec injector in the 01 with stock TC and turbo and its nearly clean as stock. Till ya stand on it!!

 

[ameristar1]

Ok, I think I have something to work with now. IH MD, sleeper, built 6.9 with hot cam, headers, 450hp capable turbo, intercooler, 1600 rpm stall, gear for 68 mph at 1800 rpms, 3800 rpm redline.

Now if the motor can just produce 350-375hp and around 650-700 ft/lbs of torque without scattering itself, it would make a good test subject for the cams that I have in mind. Putting 3000 miles a week on something like this should be a real test.

 

[1320Cummins]

I just dont know if I see the IDI staying together at those power levels running 3000 miles a week. I question how long a 5.9 Cummins would stay together at 400hp in a MD running 3000 miles a week??? But I guess we wont know about the IDI till you do it What are you going to do about the wrist pins? Can a IDIT pin and rod be made to work with a 6.9 piston?

 

[ameristar1]

The thing that I was going to do with the assembly was to deep cryotreat everything and barrier coat the pistons and pins. I am a step closer to getting the basic cam grind together, and after I check the modeling to see how the hp and torque curves are going to be shaped, it'll determine the boost that the motor will use. What I'm hoping for is to keep the boost moderate at the desired power level, and that way the reliability stays.

And the IDI Turbo rods will fit, but a custom piston will have to be made with the smaller bore/bigger pin. This can open the door to a mild decompression and put the piston at zero instead of a positive, out of bore deck height.

I had thought about the 6.9 because of the cavitation issues with the 7.3 blocks. It seems that the 7.3 blocks will need more work, like a full sleeving job to make it viable.

What are your views about a hot rodded HX/HY 35 or 40 turbo?

 

[1320Cummins]

I think the cost of custom pistons would push me toward the 7.3. I sleved one cylinder on my S-1600 due to what looked like injector failure damage.
Just do like I did and pick out a new looking 7.3 block and go with it. I think you will be able to tell if the cooling system was over looked and the block is suspect. IMO the ideal block would be from a low mile pickup. I like the 7.3 mostly for the IDIT rods, better heads/bolts, better IDIT head gaskets and a bit more low end. I say this forgetting that you pretty much need the pistons to lower compression.
My number one concern (after wrist pins) would be the rods.
As for the HX 35/40 hybrid I would recommend it for this application to about 350hp with I/C. Some people do not like the hybrid due to its small shaft but I believe those people are using it as a single at like 450+ hp.
If you want to get exotic you can go Schwitzer S-300 62/12 maybe 62/14 either should be good to 400hp with I/C. Or stage a hy-35/9 with a Schwitzer 66/14. Or best yet a pair of HX-30 turbos on your custom headers.
Any way you go id suggest a quality external waste gate.
Here is a picture of the HY on my MD truck next to a S300 62/12 next to a Schwitzer K-31 71/16
http://viewmorepics.myspace.com/ind...dID=59960303&albumID=2529058&imageID=41078291

 

[ameristar1]

I think the cost of custom pistons would push me toward the 7.3. I sleved one cylinder on my S-1600 due to what looked like injector failure damage.
Just do like I did and pick out a new looking 7.3 block and go with it. I think you will be able to tell if the cooling system was over looked and the block is suspect. IMO the ideal block would be from a low mile pickup. I like the 7.3 mostly for the IDIT rods, better heads/bolts, better IDIT head gaskets and a bit more low end. I say this forgetting that you pretty much need the pistons to lower compression.
My number one concern (after wrist pins) would be the rods.
As for the HX 35/40 hybrid I would recommend it for this application to about 350hp with I/C. Some people do not like the hybrid due to its small shaft but I believe those people are using it as a single at like 450+ hp.
If you want to get exotic you can go Schwitzer S-300 62/12 maybe 62/14 either should be good to 400hp with I/C. Or stage a hy-35/9 with a Schwitzer 66/14. Or best yet a pair of HX-30 turbos on your custom headers.
Any way you go id suggest a quality external waste gate.
Here is a picture of the HY on my MD truck next to a S300 62/12 next to a Schwitzer K-31 71/16
http://viewmorepics.myspace.com/ind...dID=59960303&albumID=2529058&imageID=41078291

One of the turbo shops was telling me that the Schwitzers are really nice, I made some calculations for a low to no smoke system (misplaced them again, but just take a few minutes to do) and based on the numbers and the intended use, running a single would make sense because of the space. I don't drive my work vehicles super hard because of the potential downtime.
The cam timing and headers will make it so that 1500-1600 rpm shift points won't lug the motor (if it was a stick) and the throttle response will be like a gasser. This thing will barely boost going down the highway, so the fuel economy should be good.
If you have any ideas as far as twins are concerned, I'm open. I just don't know where to put them in a MD chassis
That compound HX/Big Schwitzer would be interesting also, but you think with an automatic that you would have to go loose on the convertor to get the big charger to light or that small turbine on the HX would be good enough?

 

[1320Cummins]

I will look over my MD tomorrow and see about twin placement. I am thinking the 35/40 hybrid mated to a 14cm non wastegated exhaust housing should be a great way to go. Throw on a Turbonetics external WG and if you want to get fancy an electronic boost controller.
http://www.aempower.com/ViewCategory.aspx?CategoryID=68
I will be installing below link on my MD very soon...
http://www.turboneticsinc.com/evolution_wastegate

Edit: The large turbo in a compound configuration will light when its ready. The idea of the compounds is that the small turbo spools on the low end and big spools in the top end. If you are thinking the compounds with the HY you will most likely need to do dual external WGs. One WG for each stage. Unless of course you can get a WG actuator for the large turbo that will open at your peak desired boost pressure. What kind of boost do you have in mind?

For converter stall you only need to keep in mind the SMALL turbos spool ability.

BTW, my 4.56 gears came in today but they sent me gears for a M190T instead of my G175T

 

[ameristar1]

Ok here are the maths to get 455hp (flywheel)/350hp (at the wheels using 30% as drivetrain loss). This is a low to no smoke set up that runs 125 degrees for inlet temp.

Amount of air needed: 63.4 lbs per minute
Amount of boost needed with losses, 3800 rpm redline, 445ci: 30.62 psi (absolute)
Pressure ratio: 2.235

Usually the inlet temp is set at 130 degrees but an extra 5 degrees off won't hurt anything, and based on the pressure ratio, if I can get the motor to just make 204hp or so naturally aspirated, it'll hit the number under boost. I'm not afraid to smack that thing with almost 31 psi because it's not continuous.

Fuel wise, we're looking at 228cc's /1000 strokes at the pump, 228cc injectors (we'll say 230cc's to be safe) and that is within the realm of doable with a DB2. Possibly with .350" plungers and a careful tune of the timing and fuelling curve so she doesn't defuel before the cam maxes out.

Let's say with the compounds the little guy turns on at 1100-1200 rpms, starts going good at 1800, then the big one rolls on from 2000 rpms on up and it's party hard to 3800 rpms. With the boost controller and proper turbine sizing, it should be lag free.

If the automatic is used, 1600 rpms should be enough stall to get everything going and by the time it goes into lockup in 3rd and 4th there should be more than enough load to spin the twins real good. The small parallel twins I know would hit low and keep you pinned until you let off.

Tell me what you think.

 

[1320Cummins]

I am having trouble finding any specs for the HY-35 or the 66mm Schwitzer.
I can tell you that the HY-35 will make about 4-5psi boost just by running the motor to red line with no load. This meaning you will want to gate it at what ever you want your peak cruise boost to be. The HY-35 will behave a little better on the 6.9 . I am kind of tempted to recomend the HX-35 W/12sq.cm. housing. But if you want very quick spool you will want to use the HY.

Sorry if this is getting confusing I am doing my best to turn my thoughts into words;p

 

[ameristar1]

I am having trouble finding any specs for the HY-35 or the 66mm Schwitzer.
I can tell you that the HY-35 will make about 4-5psi boost just by running the motor to red line with no load. This meaning you will want to gate it at what ever you want your peak cruise boost to be. The HY-35 will behave a little better on the 6.9 . I am kind of tempted to recomend the HX-35 W/12sq.cm. housing. But if you want very quick spool you will want to use the HY.

Sorry if this is getting confusing I am doing my best to turn my thoughts into words;p

No problem, I have the same problem;p and I follow you just fine. We think fast and combos just fly around in the brain. How much room did you find in the MD with the twins?

 

[1320Cummins]

Ah its been raining most all morning and my shop is cluttered with third member crap where I would normaly pull in vehicles. It will probably be this evening. I might take some pictures.

 

[ameristar1]

That's fine, but the long and short is this sucker is gonna run hard. I talked to Barnett's Performance today, and I asked him why it was so hard to get 300-350hp out of these things, and he tells me, "what are you talking about, we get that kind of power out of them all the time". Makes you wonder.

 

[1320Cummins]

I have no idea who the people you mention are but they might just be getting a bit carried away with the correction factor on their mind dyno. I am willing to bet if you just threw a good bit of fuel at a IDIT and a bit of n20 (fingers crossed) it would easily put down 350-400. Not long ago it was insane to put down 600-700hp with a 5.9 but in all truth it was all about flowing the fuel to do it.
I have never cyro treated anything and I do not not know how well it works if at all. However I do see 4340 Billet rods in your future if you want to keep the IDI alive at 400 or more hp.You might try getting on Comp D and talking to some of the PS guys about modifying stock rods.
Dont forget the water injection system! I have a Snow stg2 that needs a home and im thinking I will try it on the MD

 

[ameristar1]

The cryotreat does work, and the folks who started all of it is in Decatur, Il so they're local. Your right about the rods, and maybe getting a set done might be in order, but for now using a lighter but stronger piston, altered cam timing and some ARP 220000 PSI fasteners should be ok with the IDIT rods. The PSD folks are boosting their engines to near 40 psi with the forged factory rods and stock cam timing.

The water/**** system is mandatory, even though if the turbo system is designed properly it will just be icing on the cake.

 

[funnyman06]

I like where all of this is going. Hope we can see some good numbers off this engine when you two all done with it.