Finally Did a Drive Pressure Test

Wrightman

Wrightman

530.221.6161
Joined
Apr 10, 2008
Messages
385
We are getting ready to put some new turbos on my kit and finally got around to doing a drive pressure test. It was the last thing we needed to do before we tried something new. At 50lbs of boost I was making about 80-85lbs of drive pressure.:doh: I am glad we finally checked it, we knew it was bad and now we will know what progress we make with the new set up. I may just run a single for a little while during our search for the injectors we want. I still can't hold a head gasket and I am sure this is why. I am thinking of o rings and we have the tooling to do both but don't know where to start with protrusion of the wire on a 6.0 so we will see what happens.
 
You may be loosing head gaskets because of your backpressure. That is a ton.
 
I know this is a newbie question but I am new to the compounds and am wondering what is the best drive pressure to have? Like I said I am just learning about how all this stuff works. Thanks.
 
bigastrk said:
I know this is a newbie question but I am new to the compounds and am wondering what is the best drive pressure to have? Like I said I am just learning about how all this stuff works. Thanks.
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It doesn't matter if you are running a single, twin, compound, etc, you use the same principles. That's why the hp chargers are always wastegated in a well balanced set-up. Otherwise you end up with extremely high backpressure, low horsepower, blown head gaskets, dyno graphs that look like hills not mountains, etc.

There are other factors to consider though; compressor wheel sizes, turbine wheel sizes, compressor covers, turbine housings, how the exhaust is directed etc. Then of course you have fuel, programming, vehicle use, and a number of other factors. Making a compound set up work is easy, making it work well and the most efficiently they can, takes a lot of time and effort.

Please don’t get me wrong, I’m not bagging on Wrightman at all. I applaud him for not only making his own setup, but actually dropping his draws and letting us all know what he is working with. Takes a big person to say, my setup isn’t working and I need to change it. Thanks Wrightman! We have been messing around with our compounds for a little while and are still trying to dial them in. In fact, we were originally working on a couple different setups and are putting a few of the larger setups on hold, until we can dial in the smaller setup.
 
We have done enough builds to know what we need as far as drive pressure but when we started my build it was with what was laying around. We will definitely have a way better set up on this next go around now that we have a baseline. We weren't sure what the 6.0 could handle so we didn't want to spend a bunch money and find out that we needed rods, etc. I am glad we practice and do R and D on our own stuff.
 
Wrightman said:
We have done enough builds to know what we need as far as drive pressure but when we started my build it was with what was laying around. We will definitely have a way better set up on this next go around now that we have a baseline. We weren't sure what the 6.0 could handle so we didn't want to spend a bunch money and find out that we needed rods, etc. I am glad we practice and do R and D on our own stuff.
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Sounds like I stuck a nerve. I wasn't trying to. Sorry if I offended you. Please read below. I think you guys are doing great and helping to educate a lot of people out there.

Trusted said:
Please don’t get me wrong, I’m not bagging on Wrightman at all. I applaud him for not only making his own setup, but actually dropping his draws and letting us all know what he is working with. Takes a big person to say, my setup isn’t working and I need to change it. Thanks Wrightman! We have been messing around with our compounds for a little while and are still trying to dial them in. In fact, we were originally working on a couple different setups and are putting a few of the larger setups on hold, until we can dial in the smaller setup.
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The stuff we are working on is completely different than what you are doing. We are working on production style kits, not custom building. You will or should always be able to dial a setup in better than we will. Our kits are being designed with basic information needed to size the chargers and here is your kit; ready for install, completely turn key. Don't need to lift the cab, no special tools required, factory y-pipe and down pipe remain, as close to a direct bolt on as possible that anyone with basic mechanical knowledge can install.
 
Backpressure is a big contributing factor to head gasket failure not to mention horsepower theif.
 
HP chargers are NOT always gated. A very well matched set for fuel only use doesn't need gates. Mine were speced by arguably the best guy in the business...no gates and a bit better than 1:1 @ 62psi. Spools right now and makes more than enough power.
To be fair...there was some custom work done but it doesn't erase the fact That gates are NOT a necessity.
 
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I guess I should have said usually. The 6.4's aren't gated either.


What rpm does you little one start lighting?
 
Cool p!ssing match. Tylers truck was running 60psi boost and 85psi back pressure. That why we gated it a little more. There's pics on the nation of his new gate. With the 6leaker we had togo smaller on the exhaust housing in order to have good spool up.
 
No nerve was struck just putting out info and letting you know what we started with. We will have it done someday.
Trusted said:
Sounds like I stuck a nerve. I wasn't trying to. Sorry if I offended you. Please read below. I think you guys are doing great and helping to educate a lot of people out there.



The stuff we are working on is completely different than what you are doing. We are working on production style kits, not custom building. You will or should always be able to dial a setup in better than we will. Our kits are being designed with basic information needed to size the chargers and here is your kit; ready for install, completely turn key. Don't need to lift the cab, no special tools required, factory y-pipe and down pipe remain, as close to a direct bolt on as possible that anyone with basic mechanical knowledge can install.
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Wrightman. How are you guys coming with injectors. Did those swamp ones do what you were looking for. I think I remember you saying they were 250cc's. You know what's funny, as soon as you say twins or compounds people expect big HP. I can make the same HP on a single 74mm charger as I can with a compound setup with a 62-74mm setup or close to it anyways. The difference is drivability. The ability to daily drive that 500 plus HP. But because you have twins you are suppose to have huge HP. Oh is your guys kit a bolt on kit and do you have to lift the cab and how many sets you guys got out there. Just questions we are all thinking. Thanks.
 
hpprose said:
Backpressure is a big contributing factor to head gasket failure not to mention horsepower theif.
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it's definately a horsepower thief, but I don't get how it's hard on head gaskets...

FAR higher temperatures and cylinder pressures during combustion... at 50psi of boost and 18:1 compression ratio you've got 900psi in the cylinder... now shoot a big shot of diesel in there 15-20* BTDC and what do you think happens to the cylidner pressure?

I'm guessing it's a lot higher than 85psi
 
The 250's were nasty and not streetable. They even were down about 90 HP. There is another guy that keeps getting the same injectors that I do from swamps, it is the guy that you made a post about having II twins from pela motorsports. He has the new set and says they are great and he made 579RWHP on a single 62/70. Hopefully I can get about the same result. I bought some other injectors that were very mild to run until swamps finishes another set for me. I agree on what you said about the compounds and big HP. Our kit could be bolt on if you didn't want a 5 Inch down pipe. We have one other kit we are doing right now and we are totally reconfiguring mine. The customers truck is going to have a 62 over a 74.
We have about 3 other guys waiting for my r and d to be done. I want just 5-600 daily not trying to break any records with this truck. Our state is killing our industry right now and I am looking for a project that I can play with and daily drive.

Redneck6.0L said:
Wrightman. How are you guys coming with injectors. Did those swamp ones do what you were looking for. I think I remember you saying they were 250cc's. You know what's funny, as soon as you say twins or compounds people expect big HP. I can make the same HP on a single 74mm charger as I can with a compound setup with a 62-74mm setup or close to it anyways. The difference is drivability. The ability to daily drive that 500 plus HP. But because you have twins you are suppose to have huge HP. Oh is your guys kit a bolt on kit and do you have to lift the cab and how many sets you guys got out there. Just questions we are all thinking. Thanks.
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I'm happy to see more people trying to get twins to work on the 6.0L.

Good Job guys!!!:rockwoot::clap:
 
I applaude you for your efforts in trying to make that ford run decently. I highly recomend experimenting on your own rig. wouldn't want to have a run away now would we?
 
by the way wrightman... I seem to be having trouble keeping my stock intercooler boots on,think you can find me some better ones? Oh ya,I also told your mechanic if he don't go tomorrow i don't go tomorrow. haa haa
 
biggreyghost said:
I applaude you for your efforts in trying to make that ford run decently. I highly recomend experimenting on your own rig. wouldn't want to have a run away now would we?
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Watch those run away quotes I don't want anyone to think it was our shop that it happend at. We already know that anyone with a credit card can make a dodge run.
 
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