The forced air induction\more fuel thread...

[turbonator]

i decided to start this thread to discuss turbocharging/supercharging, and the rates of fuel needed....:thumbsup: (also to stop hijacking 6.2turbo's DB-4 thread...LOL).... so we have discussed the gm-x turbos, the he-351VGT, and the ATT... does anyone else have something usefull to add?

 

[6.2 turbo]

I'll get some drive,and boost pressures on the hx 52 fairly soon. I may have to wastegate it ,since the exhaust housing is a 16 cm. I rather wouldn't though.

 

[robzombie4551]

I am installing a custom hx 40 with a 16cm^2 exh. housing/ int. Compressor wheel: 60mm in. x 85mm exh.

Hopefully I'll have it on in the next week or so and do some testing. I will wastegate it to 20lbs. and test in all six tunes to see what if any re-tuning will be neccassary.

If interested I will post pics and results of said install.

 

[Woody35]

I am installing a custom hx 40 with a 16cm^2 exh. housing/ int. Compressor wheel: 60mm in. x 85mm exh.

Hopefully I'll have it on in the next week or so and do some testing. I will wastegate it to 20lbs. and test in all six tunes to see what if any re-tuning will be neccasary.

If interested I will post pics and results of said install.

im very interested! im curious how its going to spool with the 3.42 gears and how your doing the downpipe since im looking to replace my turbo next summer.

 

[handcannon]

I saw something yesterday that I've never seen before. I was looking at a Mustang, probably late 90s era, with the 4.6L motor and supercharger. The young man had just recently rebuilt the motor. At first glance it looked like a turbo, but it was belt driven and setting in front of the serpentine belt drive system.

I don't know how the efficiency would compare to an exhaust driven turbo as there would be some HP loss through the belt drive. But it seems like this kind of system would reduce heat in the exhaust system that backs up into the heads, which could help the 6.5 higher temps in the passenger head.

Has anybody here had any experience with this kind of supercharger?

Don

 

[robzombie4551]

Radial compressor that looks like a ac unit?

 

[Slim Shady]

Paxton superchargers. Look them up, they have been around for a long time. I prefer the old Roots style superchargers. I already have a design for one and a mock up. Problem is with how expensive it is to have the drive belt portion machined.

But that project has been tabled for some months now, FUNDS and time.

 

[turbonator]

Paxton superchargers. Look them up, they have been around for a long time. I prefer the old Roots style superchargers. I already have a design for one and a mock up. Problem is with how expensive it is to have the drive belt portion machined.

But that project has been tabled for some months now, FUNDS and time.

we have a 6-71 blower, but we are missing lots of pieces for it.... we are also looking into the eaton m-112's, this is the same supercharger that the bullet 6.5l's from australia are using.... also we have jokingly talked about doing twin m-90 eatons, as they are more plentiful....

 

[turbonator]

I saw something yesterday that I've never seen before. I was looking at a Mustang, probably late 90s era, with the 4.6L motor and supercharger. The young man had just recently rebuilt the motor. At first glance it looked like a turbo, but it was belt driven and setting in front of the serpentine belt drive system.

I don't know how the efficiency would compare to an exhaust driven turbo as there would be some HP loss through the belt drive. But it seems like this kind of system would reduce heat in the exhaust system that backs up into the heads, which could help the 6.5 higher temps in the passenger head.

Has anybody here had any experience with this kind of supercharger?

Don

i have seen them around, maybe an interesting idea, and for sure a lot less heat.... not sure about power losses though... i would imagine that the boost comes on fairly quick.... the belt drive superchargers could be pulleyed to do 2-5psi boost at idle....

 

[turbonator]

here a pic of the bullet set-up..... it will set someone back a cool 1500 for used, or 3500-5000 new...

 

[robzombie4551]

Turbo is more effiecent and only loses down low off the line.

Imagine the turbo and exhaust setup you would have for that crazy money. You could have W/M, intercooler, turbo, and custom exh. with 5g and some money left over if done right.

That's cool for the wow factor only IMHO.

 

[turbonator]

Turbo is more effiecent and only loses down low off the line.

Imagine the turbo and exhaust setup you would have for that crazy money. You could have W/M, intercooler, turbo, and custom exh. with 5g and some money left over if done right.

That's cool for the wow factor only IMHO.

that picture is only to show what the kits look like, we can do our own set up for around 800.00... IMO the turbo is not more efficient, the super charger creates a 1/4 of the heat that the turbo makes, and the egts are below half at the same boost.... sure you can do something good turbo-wise, but in the end it is all still tied to the same unbalanced crappy OEM side mount, everybody has been there and done that....

 

[1995yukon65]

My redneck side just popped out for a minute... If you are running an intercooler, it wouldnt be too hard to twincharge it with the bullet supercharger. The inlet for the supercharger is setup to acommodate left or right side inlet. Sooooo in theory, you could run the turbo thru the intercooler then into the supercharger.

With the right turbo, you could have excellent top end and with the supercharger you have all the low end you need.

Just thinkin'

 

[Woody35]

My redneck side just popped out for a minute... If you are running an intercooler, it wouldnt be too hard to twincharge it with the bullet supercharger. The inlet for the supercharger is setup to acommodate left or right side inlet. Sooooo in theory, you could run the turbo thru the intercooler then into the supercharger.

With the right turbo, you could have excellent top end and with the supercharger you have all the low end you need.

Just thinkin'

i dont know if these trucks can flow enough fuel to support that

 

[robzombie4551]

I don't agree with you but that's what this is about, ideas.

With the properly designed exhaust ie; center mount [balanced flow] or custom exhaust and properly sized turbo it will beat a super charger mid and top end [where I tow most] and most importantly something you have overlooked is the stress that a supercharger puts on the engine, specifically the crankshaft[which is one of the 6.5 weaknesses].

Twin turbos of the right size would also be advantageous because you could use small turbos and get more volume and decent boost off the line without exhaust restrictions up top.

Turbos also come on soft compared to superchargers which will stress the motor more by giving the power almost on demand and run off the crank [bad harmonics and ancillary stress]and generate more heat in the higher revs unless you use a large/or under driven supercharger[less bottom end boost/less rpms] to keep boost from becoming a heat pump just like on a turbo.

Superchargers make more boost at cruise which makes them less efficient[parasitic loss]. they still use power by spinning at engine rpm and are rpm dependent on whether over/under driven, makes more or less boost which is one advantage to tuning[change a pulley and your there] but [also still using power that a turbo wouldn't be].

A turbo is just along for the ride when not boosting when properly sized.

IMO the turbo is not more efficient, the super charger creates a 1/4 of the heat that the turbo makes, and the egts are below half at the same boost....

EGTS are the result of exh.backpressure and the amount of fuel injected and timing among other factors. A supercharger would get the nod over a turbo in that area [backpressure].

Let me know how much heat a supercharger generates at 15/20 lbs of boost if you install one. I'm not busting you just looking for some real data running one on a 6.5.

Both have their merits but in my case I'll stick to turbos as the safest and most dependable way of forced induction on a 6.5. I don't want the added stress on the bottom end of my motor.

 

[handcannon]

Radial compressor that looks like a ac unit?

If this question is for me, the unit looked exactly like the front half of a turbo, the air "pump".

I've heard of the Paxton supercharger before, but never have seen one. This one I saw looked like it would be reasonably easy to fab a mount for and to adjust the output by changing the pulley size. My comment about HP loss was about the belt drag on the motor, even when at no to low boost. This type of supercharger would definitely make belt changing a bigger chore with the intake tubing and charger to manifold tubing in the way.

I'm really interested in the info this thread brings out. I may not fully understand everything at first, but keep this thread rolling.

Don

 

[buddy]

An HX52 with a 16cm^2 turbine housing? Thats pretty crazy with how large the wheels are. I think any normal 6.5, for daily driving, or towing, or general work truck would be more than comfortable with even the 14cm^2 T3 turbine housing with 3" V-Band outlet HX40. That is a bit smaller than the ATT, but plenty bigger than the GMx. The wheels available are also bigger than the HX35 or HE351. So in that 14cm^2 housing you can get a 76mm inducer turbine, that has a 64mm exducer. Compared to the 70/60mm of the HE351. You can also get the 70/60mm turbine in the HX40s.

When I went and looked at the GM8 and remeasured the turbine housing, it seems like its about 10cm^2 cross section area above the inlet. Its so small.

Now, with max fueling of a stock DS4, you can push an ATT to 25psi boost, so even the 16cm^2 to 18cm^2 housings are good non-wastegated on a 6.5L, if you have the fueling, which means modified DB2 or DS4 and/or better programming to manipulate the fueling of the DS4.

Max fueling on a DS4, depends on the cam ring and the plunger size. Bison measured some things to assist and his plungers were 7.86mm diameter, I have heard that there are 6.86mm diamter and potentially a bit larger. That would make a huge difference in fueling. The Cam rings from 5068 and 5067/5521 are different, which is why 5068 can output a little more fuel, little more stroke.

So you could have a range of 102mm^3 and theoretically up to 200mm^3 displacement depending on the plungers, 133mm^3 on Bison's measurments. Lets say 90% of the stroke is actually available to use and its 92mm3 to 182mm^3. Because as RPMs increase the time to actually get fuel through the rotor decreases the pulse width of injection actually decreases with RPMs, but the IP compensates with the transfer pump increasing pressure with RPM, 10-130psi. More pressure, less time and can still get more fuel out at higher RPM.

So there are a few ways to increase fuel output, increase bore, stroke, or pressure. The input to the transfer pump is fed by the lift pump and the spilled fuel from injection. There is a valve that closes off spill pressure in the lower IP fitting. If you tighten the screw it can increase pressure from spill to transfer pump. This spill to transfer pump is how the IP can keep running even without LP pressure, because it gets pressure from its own injection and spill. This is also why good LP pressure helps maintain high RPM power.

 

[Woody35]

how reliable would a ds4 maxed out be driving everyday with an intercooled t4 hx40?

 

[buddy]

Ive been driving one that way for a couple years. As long as it has good supply pressure and lubricated fuel it will do fine.

If physically modifying the DS4, it may become necessary to remap the fuel pusle width, so that it doesnt become overly sensitive on the pedal. If you increase the stroke or bore then it doesnt need to spray as long to get the commanded rate of fuel, so have to redefine what all the commanded fuel rates really mean in terms of pulse width per RPM (pressure). That is the downfall of most modifications is fully implementing the modification in software as well as the hardware, so driveability is still good. The injection pulse width is actually defined in degrees. And the Fuel Solenoid closure time pulse width is defined in milliseconds. Some of the timing is referenced to the crank and some of it to cam. So it gets kind of confusing pretty quick.

 

[Woody35]

so if i wanted to get a tune that maxed out my ds4 is there any suggestions on what i should tell the person doing my tune?