? Best After market Turbo

[buddy]

The larger the housings and larger wheels it will make spooling more difficult, meaning not just lag, but also peak pressure, because larger turbos with great efficiency create less backpressure but get closer to creating as much boost pressure on the intake side and backpressure on the exhaust side. I believe the schoolcraft turbo is wastegated, so that just says the wheels themselves are smaller, less efficient ones but uses the wastegate to bypass the turbine to prevent too much backpressure and boost. I have seen versions of Kennedy programming, recent and dated, and neither would support enough fueling to hit even 20psi on the ATT. I run 20+ psi on the ATT with the fueling I program, but on a smaller turbo I could easily push 30+ psi, have done that with the GM4. If they can wasteage at 25psi that means the housings are a little smaller than ATT and the compressor wheel.

I just know I would never pay $1700 for a turbocharger. That is subjective, not objective. Im not even sure what you get for that $1700 since it says turbo assembly only.

Compressor maps and dyno numbers aren't the final word on what works well. I gladly accept all the objective, quantitative data of the ATT vs GMx on IAT, EGT, ECT, MPG, MPH, PSI, ect....that gives us qualitative information as well. The ATT kit is a good value. The schoolcraft may work as well, but is that as good of value, when I imagine you could get a knockoff similar to it for $320 on ebay.

The schoolcraft turbo probably maintains the off the line spooling performance better than the ATT, but I would find it hard to outperform the ATT when hauling heavy loads.

 

[chevytrucksonly]

To all from the "Original Poster"

First, there is no one hijacking or otherwise as far as I am concerned-just a healthy debate of info, objective and subjective: in which both are equally important. The dialog has be very helpful and interesting at times.So many threads or simply boring!
The turbo market is a confusing one with many claims(that may not hold water)and the pricing is outrageous and intellectual insulting when comparing products and trying to get relative data.
I want to make a note about "Walking J or The A Team" and not in defense of. I have read nothing but positive comments about them and there Products, however I have not purchased anything from them. I called and spoke with a gentleman late this past Friday afternoon about there turbos. He was very candid and detailed in explaining their design verses GMs and design purpose of their turbo. To me it speaks volumes if he stands behind his products as he says. He described their exhaust neck design went out at straighter angle than GMs and it produced more flow but not increased boost-which brings up more ?s for me and the benefits of their turbo for me. Anyway I have dealt with Kennedy, Peninsula and BD (which no longer sales 6.5 parts) for many years, and I hope Walking J matches up with the others creditability standard.

To expand on my truck situation and a couple of factors I must consider in a turbo:

1)An important factor is that I will be putting Peninsula P-400 long block or their P-400 (18:1 with marine fuel system) complete build in place of my factory 6.5.
So what turbo I choose will need to match up to work well with the P-400 build. The only way you can get the P-400 is in a long block unless it is built for you.
I use this truck on the farm, towing, hauling and dumping and running into Atlanta sometimes (only if I have to).

Thank you for the great input.

Dr. MDS

 

[turbonator]

there is also the schwitzer s-300 turbo, similar to the one that 6.2turbo is trying out... it is suppose to be an exelent option,( it is one of the turboes that peninsular uses).... also the td-07 from the 7.3l idi kit that banks makes is good as well..... i am going to try a holset hx-35 non waste gated one that i aquired.... also we have a 351vgt and have had great results with it just by controlling the vanes with a double action turbo-master styled controller......

 

[DennisG01]

Chestatee - good, glad to see I'm not steering this thread away from your initial intent. Your thread caught my attention as it seems you and I are after the same thing (especially if you go with the 18:1).

I've been trying to research WG vs Non WG turbos without much luck. Is one inherently better than the other for towing (assuming same size housings/wheels)?

Buddy, you referred to fueling programs... do you mean to say that you have more fuel coming out of the IP than I would? Or, are you referring more to the parameters as to when the fueling is called for?

There's a nice stretch of a hill on a local highway - it's on the way to one of the lakes that I take the boat to. I use this as my "proving ground" for comparing mods to the truck. It's about 1.1 miles long and I always start (from a standstill) at the same spot and stop my recording (I don't stop the truck) at the same spot. I would do the same thing with whatever turbo I get so we could compare the direct, quantitative effects of it vs GM-8.

A VGT sounds like the best of both worlds, but that sounds like it would be very expensive. Are there reliability problems with a VGT (more moving parts)?

 

[buddy]

Buddy, you referred to fueling programs... do you mean to say that you have more fuel coming out of the IP than I would? Or, are you referring more to the parameters as to when the fueling is called for?

A VGT sounds like the best of both worlds, but that sounds like it would be very expensive. Are there reliability problems with a VGT (more moving parts)?

In short yes. There are fueling modifiers that one can play with in the software to force some more fuel out of the DS4.

The HE351VGT can be had used for a few hundred bucks. Turbonators dual mechanical actuator system sounds pretty promising, and its a beefy turbo, very heavy, aside from the electronics which are removed for the mechanical actuators in Tubonators choice, the turbo seems to be quite reliable.

 

[Woody35]

also we have a 351vgt and have had great results with it just by controlling the vanes with a double action turbo-master styled controller......

can we get pics?

 

[vdb11]

can we get pics?

Agreed I have a single action TM style on my VGT, with double nuts on the other side to prevent the spring from pulling the vane ring too far into what seems to be the exhaust brake position, but I would like to see what you have turbonator, it probably works better than what I have

To the original poster and Dennis, as was said, the cost really isn't too bad. I got mine off the big auction site for $212 including shipping three months ago, turbonator got theirs a while ago when dealers were ripping them off trucks and replacing them when they filled up with soot instead of cleaning them, so they got their turbo very cheap (darn you turbonator ). With everything I put into it, I had around $425 total. it can be done much cheaper than that. I got ripped off buying the exhaust parts, which included a 3.5 to 4 piece and 3.5 elbow for the downpipe ( I have a 4 in exhaust so I made my own 4 in downpipe), a v-band clamp for said downpipe, a straight 3 in piece for the intake and a 3 inch elbow for the custom upper intake, all of which totaled over $100. Other than that it was just a few small things like an adapter fitting for the oil line, a rubber line for the oil drain, and some silicone couplers for the intake and springs, threaded rod, so another $100 for me. I know of someone that just took the 3.5 elbow on the turbo and welded it to their aftermarket 3 in downpipe as another option. Overall not too bad of an investment. Like I said, its just another option to consider, it does take a good bit of work.

Like buddy said, increasing fuel would be highly recommended. Now I have mechanical injection, and with my custom elbowed GM-3 I had the pump turned up about 3/16, which smoked some under hard acceleration and bogging. Since the turbo I get absolutely no smoke, maybe a tiny bit if I shift early and bog it. I noticed a lot more low end snap, where fuel is probably closer to adequate, but as the boost rises to over 10-12 psi in this beast (like buddy said, it is very large) you can almost tell/feel that the extra air and boost is worthless, as it is underfueled for this turbo at that point. Over the summer I will be doing more IP work and increasing fuel again (after some bottom end work) to see what it does.

There are several options and the VGT is one of them. The ATT is a great choice too, although I have no experience, but have nothing but good things. As turbonator mentioned, there is Switzer turbos, heck if you wanted to be wild you could fab up the exhaust for an IHI turbo off a Duramax or a Garrett off a 7.3. Good luck with the choice, and I am anxious to see your P-400 build so some of us can live our dreams through you

 

[cub124]

I want a P-400 :hihi:
Im also going to the 6.7 vgt, head studs and 20:1 CR if interested ill let you know how it turns out. hopefully this pump will put out enough fuel!!! (6.2 stock pump)