Compounds - A due diligence quest

[wmoguy]

While I'm way pleased with the 60 series wheel upgrade on my ATS turbo; I'm left wanting more. The 2k+ rpm spoolup and boost levels IMO are more than sufficient, however I want boost below 2k, at my altitudes and driving thru the canyons it's a major plus.

Anwho, this isn't a bench racing thread, I'm fully prepared to do this over the holidays when I have the time to take the truck off the road. For simplicity sakes I believe I'll move my batteries to the bed mounted tool box, which will leave the passenger side with a nice open spot for two shiny turbos and the driver side a big fat air/water intercooler. A little plumbing work will be necessarily to feed the chargers hot gases and then expel them, but I don't think it will be too bad. The thought of not having to mess with turbos, air boxes, and other junk on the top of the motor is VERY appealing

My question is turbo selection. I'm a little partial to Holset turbos, mainly because they are very interchangeable and pretty inexpensive. I can get my hands on a HY35 pretty easily and think it would make a nice small turbo and get me that low end spool I really want. For the big charger I'm wondering about a hx50 which I can also get fairly reasonably priced. For the fuel I am pushing it almost seems to big, I keep thinking about an hx40 for my bigger turbo. The 40 really only moves about the same CFMs as our stock turbos, but it appears to be way more efficient in the sub 25psi range.

In summary, the goal is more low end boost, and good towing twins. I'm not interested in pushing tons of boost at high RPMs or a supercharger/turbo combo. I'm interested in efficiency in the realistic power band of this motor. I don't intend to lower my compression, studs I will go back in for. So I'm guessing I need to keep my boost #'s below mid 20's to be conservative.

Thoughts? I'd be most appreciative to hear from those with turbo matching experience. I feel a little green when it comes to picking the right maps for this application. PLEASE, lets not make this another bench racing thread folks. If you have some real world experience you can share I really want to hear it, if your experience involves what you read on the internet or what "your buddy says" please be kind and refrain. (sorry to have to be so blunt there guys)

 

[ocnorb]

 

[typ4]

You need the torque cam also, that helps low end and low speed boost.

 

[wmoguy]

You need the torque cam also, that helps low end and low speed boost.

yea your probably right Russ. I just really don't want to tear back down that far again if it can be avoided in any possible way

 

[FordGuy100]

Whats your low end boost now? I can go WOT in 4th at 1000rpm's and by 1100rpms have 1.5psi.

Compare to my parents 08.....in overdrive with the converter locked, 1300rpm's, I can manage 20ish psi, anything past that requires to much pedal and it downshifts.

We should just scavange one of those setups

Honestly look at the HE351VGT turbo's that come off of 6.7l cummins. My guess is they should be efficient in their maps on their motors up to 25psi...and being VGT they have a wide range of exhaust housing sizes (depending on how the veins are positioned). I here they range from 4cm^3 to 26cm^3. For reference HY35's have 9cm^3.

If I was going to do anything more than a 60-1, thats what I would do. There are people that have some nifty setups for controlling the veins with backpressure and boost (high backpressure will open up the veins, etc...)

 

[wmoguy]

Ford100: I'm not registering anything @ 1100 rpms unless I nail it from a stoplight, and I suppose at 1100 I might be registering something.

My goal is to get more like your parents 2008, but in old school skin. 20 psi that low I think will make me have too much boost up top. Ideally as I'm cruising around empty @1200-1500 in town I want to be building 6-8 psi.

BTW, you think my dad would get pissed if I took the HE351VGT of his 11' Dodge? It would be just for "test fits" I promise.

 

[FordGuy100]

Ford100: I'm not registering anything @ 1100 rpms unless I nail it from a stoplight, and I suppose at 1100 I might be registering something.

My goal is to get more like your parents 2008, but in old school skin. 20 psi that low I think will make me have too much boost up top. Ideally as I'm cruising around empty @1200-1500 in town I want to be building 6-8 psi.

BTW, you think my dad would get pissed if I took the HE351VGT of his 11' Dodge? It would be just for "test fits" I promise.

Let me clarify...the 2008 was a F350 w/6.4 PSD. Those twin turbo's make boost just about anywhere in the rpm range.

Anyways, I think the HE351VE is off of the 6.7 Cummins. Inducer size: 59.50mm, exducer size: 86mm.

 

[FordGuy100]

So we have...

Stock ATS 093 compressor wheel: 58mmx70mm (inducer x exducer)
Stock 7.3 PSD (late99-2003): 60mmx80mm
And HE351VE off of a 6.7 cummins: 59.50mmx86mm

That tells me it will flow just as much air as a 7.3PSD turbo, but have the added benefit of a VGT setup.

 

[429idi]

Whats your low end boost now? I can go WOT in 4th at 1000rpm's and by 1100rpms have 1.5psi.

Compare to my parents 08.....in overdrive with the converter locked, 1300rpm's, I can manage 20ish psi, anything past that requires to much pedal and it downshifts.

We should just scavange one of those setups

Honestly look at the HE351VGT turbo's that come off of 6.7l cummins. My guess is they should be efficient in their maps on their motors up to 25psi...and being VGT they have a wide range of exhaust housing sizes (depending on how the veins are positioned). I here they range from 4cm^3 to 26cm^3. For reference HY35's have 4cm^3.

If I was going to do anything more than a 60-1, thats what I would do. There are people that have some nifty setups for controlling the veins with backpressure and boost (high backpressure will open up the veins, etc...)

I believe hy35's have a 9cm housing. The reason the he351's go so small is for the exhaust brake function.

With the turbo I'm running (t70) 70mm inducer/ 90mm exducer, it is comparable to an hx50. The inducer on my turbo is bigger, but the exducer is smaller, so I have a higher trim. I make 5-10psi in fourth gear really low. The response is really good for such a large turbo. The max pressure I'm running is 20psi.

An 7 blade hx35 will outflow a stock h-3 compressor. If I was going to do compounds, I would probably use something like an hx50 for the atmosphere turbo, and an hx35 for the high pressure.

 

[FordGuy100]

I'm an idiot, thats what I was thinking with the HY's, dont know why I typed 4.

 

[towcat]

yea your probably right Russ. I just really don't want to tear back down that far again if it can be avoided in any possible way

i kid you not.
that torque can is the animal you need. if nothing else, take a flight over to where Russ is at and take his 4x4 out for a test drive.
I thought it was a 4.10 geared truck by the way it pulled off the line.
(it's a 3.55)

 

[Black dawg]

how much boost do you make by 1500? Ive seen several that would make 5psi at 1500.

My plan if I ever did compounds was to use the factory turbo with a smaller exhaust housing and then possibly an hx50.

 

[wmoguy]

A little further clarification

My goal involves easily building boost. Right now if I stab at the throttle even when down low in the R's I have no problem building boost. The difference for me is I want some finesse in it, and not having to stab at it to get boost. One disadvantage I have is I'm running an Auto, so when towing, especially in the mountains on curvy roads/passes I am more challenged to maintain a specific RPM unless I drive it like a manual valve bodied truck. I've got the truck dialed in pretty darn nice now in terms of good shift points and shift responseness and don't want to mess with that.

The goal is to be building boost basically always (obviously not at idle) For example, on roads like Highway 14, in the Poudre canyon, often times I don't have the luxury of stabbin the throttle to get a lil boost (to clear up smoke, etc..) because you don't get that luxury. Your in and out of the throttle ALL the time on windy steep roads like that.

Im not complaining, the truck runs great and I'm pleased. I just want my cake and eat it too.

 

[FordGuy100]

Supercharger

 

[wmoguy]

Supercharger

no thx. not interested in the parasitic loss they provide. I had twins on my 24v Cummins and was WAY pleased with the bennies vs. the single charger I had on it prior. I'm on a quest to find the right set of twins to fit this ole beast