I won't be worried until I bolt it together and see. It will have MSII-EFI with ignition control. 6psi should be totally fine. 10+ psi, maybe not?

Lou

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Home of Slant6-powered fun machines since 1988

I have run up to 29psi with my Holley and an electric fuel pump. It has been 3 years since I ran the mechanical. Even then, it was for a week or so before I decided to go electric. I don't remember much about it.

The bracket I made is for a Boost Referenced Power(BRPV). The jets hold it in place and a spring on the bracket keeps the power valve (PV) closed rather than vacuum. The carb body is drilled so the cavity behind the PV is pressurized from the carb hat. When this pressure overcomes the spring then the PV enrichment circuit is opened. Additionally, the PV circuit needs to be enlarged.

I don't have a pic at work but you can go to turbomustangs.com and search BRPV and you will find a ton of different variations.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

On the cam note, you Don't want a lot of duration, that's why you can pick up a simple MP cam that is a little bit more than stock and will run much better than any of the big cams you would use for NA performance.

Yeah the HX-30 looks to be a little bit more towards the slant's characteristics. However, I need to brush up on my map reading skills but the numbers on the x-axis or lbs/min should suggest the turbo will favor higher boost numbers. I will double check this tonight in my notes and books. It looks to be similar to the T04 .50 trim, which is what Turbonetics webpage suggests if you go under Choose Your Turbo - Turbo Matrix. I've been using this turbo T3-.50trim as the GN's base map and just pick numbers to compare it too. If you use something as a reference you can get by looking at turbo maps as simply comparing what's large and what isn't. As far as lag and boost numbers I got to refer to my notes everytime.

Where/What would you get this HX-30 off of. I have two of the new 6.7L turbos and can tell you it would be massive

Runvs can you elaborate why you wouldn't want more duration? I know with forced induction you want as little overlap as possible, perhaps you have them confused? I dunno I could very well be wrong but more duration just allows the valves to stay open longer which would allow more air to fill the cylinders each time the intake valve opens and I would especially think it would be a good thing for a turboed engine much less an N/A engine. But again I could be missing something Yes the HX30 I think is well suited for the slant. Infact from the holset website I found this info on it : "The Holset HX30 is suitable for engines up to 5 litres capacity requiring up to 035kg/s of air at 3.1." You can read the rest on the HX30 and all the other Holsets from their site here:

http://turbobyholset.com/holset-hx30/

As far as where to find one I am getting mixed results and its different than the info I found a few years ago which said they came on certain year Dodge diesels (either early 90, mid or late) and that they were on 5.9 liters. Now I am reading that it only came on Cummins engines under 5 liters which is like marine apps but I am still getting posts on other sites saying they are using HX30s and they came off early Dodges. But, even if the marine thing is true I see HX30s for sale a lot so getting a hold of one is pretty easy especially considering more and more people are using them on their cars so you can find em in the DSM forums, Dodge turbo forums, Ford turbo forums etc and Ebay also. Here is a Turbo Dodge site that shows pics of comparisions of the HX30 and other turbos like the T3 and TO4B:

http://www.turbododge.com/forums/f4/f19 ... te04h.html

Notice how much it looks like a TO4B? But the compressor housing is fatter. Also someone mentions that the turbo flows more than 46lbs/min which means it can support 460hp in theory. But I just found this also:

"Well, there are 360 seconds in an hour, and 2.2 lbs in a kg, so .35 kg/s turns into 57 lb/hrs General rule of thumb sez 570 whp!!"

.35kg/s of course refers to Holsets own site sayin how much it will flow. I'd say its a good turbo for the slant with ALOT of room to make alot of power. I also don't think any 225 will rev past its limit either although 170s could. I've read of 2.3 Ford guys with lots of head and cam mods revving past the HX30s limit. The HX35 according to Holset is probably too large as Holset says they are for 5liters and up but if you used say an HX30 turbine housing on an HX35 ( if its possible) it would make quite a bit more power as its rated at something like .46kg/s.
Geez I wrote alot SORRY guys kinda got carried away with info

EDIT: I found what you can get these turbos off of ( at least one source).Apparently they were used on 4bt 4banger Cummins diesel engines.

"The 4BT is the exact same Cummins engine as the first generation Dodge Ram Diesels 6BT except with the front two cylinders chopped off. Therefore all the Dodge Ram Cummins 6BT parts are interchangeable with the 4BT."

Not sure what all engines had the 4bt engine but from what i've read its "readily available."

You base cam duration mostly on the intended RPM range and cam lift on cylinder head flow. Overlap is tricky on a turbo engine. Too much overlap with a high exhaust to inlet pressure ratio and you dilute the intake charge with exhaust. With a low exhaust to inlet pressure ratio you can blow right through the combustion chamber and into the exhaust. If the inlet and exhaust pressures are relatively balanced as with a normally aspirated engine some overlap will help scavenge the cylinder and make more power. Generally less overlap is good and this means wider centerlines between the exhaust and intake lobes.

You seem to be forgetting that Holset is recommending the HX30 for a <5L Diesel engine. A 3.1:1 pressure ratio is just under 30.9 psi boost at sea level. You won't get .35kg/sec mass flow below 30.9 psi. The HX35 is not much larger than the HX30 and is more widely available. The earlier Dodges used Holset H1C and WH1C turbochargers not the HX30.

I think you're a bit misguided in saying a 170 would rev past a turbo's limit, but a 225 would not. Turbochargers care nothing about the RPM of the engine to which they are attached. What matters is mass flow and pressure ratios.

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Joshua

Compressor Maps
The column or y-axis dictates the pressure ratio. Essentially your absolute divided by atmosphere. So in this case (8lbs) is 22.7/14.7 = 1.5
The Row or x-axis is the Mass Air Flow which takes a couple more calculations can be seen in the excel looking picture attached.


Holset HX30 compressor map

A TO4E 50 trim


Stock Grand National Turbocharger


What you want is to have as much in the middle island as possible as that is the peak efficiency of the compressor. Hope this helps and you can use the excel image on any turbo map placing your own points. It's set for 8lbs on the Pressure Ratio scale.

Warner, Mark. Street Turbocharging: Design, Fabrication, Installation and Tuning of High Performance Turbocharger Systems. New York: HP, 2006. Print.

Edit: The points are only horizontal after you have reached full boost, so essentially it works it's way up. However, it's important you stay to the right of the surge line. To the left of the line is unstable and surging, maybe someone else can explain that more??? However, it goes back to the Holset still being a diesel turbo and better suited for high boost levels.

Runvs thats some great info, infact i've been wanting someone to break down the HX30 map in relation to the slant. My idea of it being an ideal turbo was a simple theory but since I don't understand the maps i've never been able to see whether it would actually work. So Run please show an example of a turbo that better fits the slant with the maps so I can see the difference. So the TO4E is a better fit for a turbo am I reading that correctly? It's still not in the middle where the efficiency is the best but you only have it at 8lbs so if you increased boost would the line just go up into the surgeline or would it move into a better spot in the map or what?

Both of the turbos mapped are too large for the engine, per the calculations. At maximum boost you want the operating ares to lie over the center of the "island" (optimal), or at the upper portion of the "island" (allows for detuning without losing efficiency). Allowing the turbo to surge will damage its bearings, so stay away from the surge line.

Ken

Ken do you have a map that shows the slant being in the middle area? I think if I could see one that is and compare it to Runs i'd get a better understanding albeit not a complete understanding of how to read them but a better one

www.turbonetics.com has a lot of plain-English info.
www.turboneticsinc.com/content/compressor-maps has the maps. Look at T3Super60, T04BH-3, T350, T360. These are at least "in the ballpark".
As an example of a poor choice, T04BH-3 will produce surging.

Ken

Nice HX30 compressor map. It's quite wide and efficient.

How did you come up with the normally aspirated mass flow? How did you determine or estimate the boost/RPM line?

In playing with this calculator... http://www.turbofast.com.au/turbomap.html it appears to me the HX30 is a good match for a 225 and a T04B-H3 and 60-1 may be slightly large. Of course if I'm underestimating the volumetric efficiency of the engine the H3 and 60-1 will probably work fine. They just seem to be a bit close to the surge line.

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Joshua

Josh please elaborate your findings on the HX30 I played a lil with the calc in the link you put up. Took me a min to figure out why the dot wasn't showing up but eventually I got it. Runvs I don't know if it will make any difference in your data but I used a Vol Eff calc also found on the site Josh linked and according to it the Vol Eff of the slant is just a lil over 72%. Now thats at 4000 where the 225 supposedly makes it peak power. I originally put something like 80% in the turbo calc which turned out to be a lil much and putting it down to 72% moved the dot although I can't recall how much now. On a side note, if I put the settings in correctly, the dot was dead center in at the top of the middle island on the TO4B S3 turbo. I think I had it set for 14.7psi. Shame they don't have any Holset maps in that calc. I also got a similar issue that Josh came up with about the 60-1 where it was right where the surge line was. Don't remember what boost I had running. Anyway that site has a lot of neat calculators on it.

Oh, sorry, I used the mass flow and pressure ratio numbers the calculator gave and plotted them myself on the HX30 map and found all the expected operating points to be well to the right of the surge line and in high efficiency areas.

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Joshua

My numbers were from the book cited in the thread. I ran through them very quickly and saw at times I was probably a little conservative, but nonetheless it proved my point for a given set of parameters. I have used the online calc before and liked it, but it felt like I didn't input as much as the book. The big thing I was trying to prove was at low boost the Holset wasn't a good choice. This was assuming things very different than what you or Josh can input.

A nitty gritty way to read a turbo map is to reference how much boost you will be running (the y axis) as stated above. So, if you can run, tune, and hold together 15lbs than that would be 2.0. Than you simply go down to the x axis and read lbs/min (not kg/sec) and multiply by 10 to get your horsepower. For example:
I would choose 2.0 for 15lbs of boost and 30 from the top for 300hp. So this would put me into the second highest efficiency for the Holset. This would work great for these parameters.
Option 2 would be figuring I'm going to run 8lbs of boost at max rpm (say 4500) the bottom map looks better as your are more in the middle, and the top map shows your in the bottom areas.

So all in all I think we've put some great information down and you or any reader can follow this fairly well and see given some parameters what they would choose to do. I would like to but up a proper map showing how your "dots" actually work up into the map, maybe tomorrow. But going back to the original statements I would choose the GN turbo with a goal of 300hp at 5000rpm with 10lbs. Next, will be to allow the engine to do her job, i.e. hold together and not predetonate.

Edit: one last point is that both these turbos will make equal power, and are very close in characteristics. However, I don't choose the Holset as it was designed for diesels, engines that run at higher boost levels as shown on the y-axis.

OK, but did you do your calculations for a 170 or a 225?

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Joshua