Questions on twin charging! Help wanted
11-02-2018, 07:55 PM
#1
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Questions on twin charging! Help wanted
I was looking into twin charging my XJ, running a cold side turbo through an m90 supercharger mounted on the manifold. Air intake through stock air box with snorkel. Just wanted to ask opinions and see if there is anyone with experience in twin charging
Air is pulled in through snorkel and air box across bay to turbo, compressed and sent through an inter cooler, into a m90 from boosted technologies. Running 6 psi on both(12 psi total) and exhaust straight out the hood
Air is pulled in through snorkel and air box across bay to turbo, compressed and sent through an inter cooler, into a m90 from boosted technologies. Running 6 psi on both(12 psi total) and exhaust straight out the hood
Last edited by John F; 11-02-2018 at 07:58 PM. Reason: Adding to question
11-02-2018, 08:17 PM
#2
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Why not just run a turbo by itself? I've never done twin but I have run both m90 with a 2.55 pulley and a 20g separately on the same engine with no other mods done between the 2 versions. As apples to apples as you can get. The turbo is superior in everyway.
11-02-2018, 08:21 PM
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i was wanting to make it a fun off-road and be able to run a strong 1/4. Mainly wanting the best of both worlds
11-02-2018, 08:32 PM
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When do you want to start making power? The m90 really only gave a boost in the 2k to 4k range after 8psi it just put out stupid hot air. At 5k and 12ish psi intake temps where logged at 213*f with water meth. Not safe, not fun to tune for, no low end power, no top end power. The turbo starts making power just under 2k and pulls all the way to redline at 15spi with logged intake temps without meth at 96*f.
11-02-2018, 10:49 PM
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When do you want to start making power? The m90 really only gave a boost in the 2k to 4k range after 8psi it just put out stupid hot air. At 5k and 12ish psi intake temps where logged at 213*f with water meth. Not safe, not fun to tune for, no low end power, no top end power. The turbo starts making power just under 2k and pulls all the way to redline at 15spi with logged intake temps without meth at 96*f.
11-03-2018, 07:41 AM
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I wouyld think the best way to do what you want without fighitng the crazy heat from the M90 at higher rpm would be compounded twin turbos.....small one for low end, and bigger one for top end....like the diesel trucks do
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11-03-2018, 12:22 PM
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I was going to tune it with a friend of mine that’s a mechanic and works with tuning and once I got the turbo, then when I saved up enough for the full sc kit I was going to tune it at a shop in Denver after I installed it. But that is a little ways down the road, so the turbo is my main concern. I was going to run it at 8 psi of boost, then drop it to 6 after I got the sc. but I’m having a really hard time finding piping to run the exhaust under the engine then back up on the cold side to put the turbo there, I actually can’t really find a regular turbo manifold for the 4.0. So am I going to have to custom fab the exhaust?
11-03-2018, 12:29 PM
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Another thing is that I’m going to have to cut holes in my hood to get the sc and the exhaust to fit right, so I’m going to be running cold air over the sc constantly, also custom fabbing hood scoops to full air directly over them to keep both set ups cool
11-03-2018, 07:00 PM
#11
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For the amount of money and complexity this involves I believe your cash will be better spent on higher ratio gears and a single turbo. That being said I still would still like to see this project happen.
What tuner does your friend use?
Hoodscoops will not cool the m90 sufficiently if over driven. Pre rotor meth will cool them down nicely but the air charge heats up quickly after 8psi on our motors. Even at 6psi the charge temps were above 140*f. If you are keeping the internals stock this becomes a large problem. The colder the intake air and the higher the octane rating the more oops room you have. This gives you more time to get your foot out of it and maybe save your motor.
Turbos don't benefit from air being passed over them either. Mine is tucked on the driver side between the motor mount and the firewall. The hotside is covered with a blanket. It is oil and water cooled to keep the turbo within operating temp.
What tuner does your friend use?
Hoodscoops will not cool the m90 sufficiently if over driven. Pre rotor meth will cool them down nicely but the air charge heats up quickly after 8psi on our motors. Even at 6psi the charge temps were above 140*f. If you are keeping the internals stock this becomes a large problem. The colder the intake air and the higher the octane rating the more oops room you have. This gives you more time to get your foot out of it and maybe save your motor.
Turbos don't benefit from air being passed over them either. Mine is tucked on the driver side between the motor mount and the firewall. The hotside is covered with a blanket. It is oil and water cooled to keep the turbo within operating temp.
11-05-2018, 06:37 AM
#12
I really don't want to be a Debby downer here, but with the proper turbo setup, you can have you cake and eat it too.
I think with a .42 AFR the boost will come on around 1500 and stat until close to 5000.
I think besides the heat issue with your idea, you're going to run into a space issue.
I think with a .42 AFR the boost will come on around 1500 and stat until close to 5000.
I think besides the heat issue with your idea, you're going to run into a space issue.
11-07-2018, 03:29 PM
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Seems like a lot of work for a little return on the measly 4.0L.
4.0L's barely like being stroked, let alone boosted.
Seems like a good chunk of money for a low reliability system, when a 5.3l or 6.0l could be done for possibly cheaper, with likely higher HP/TQ stock.
4.0L's barely like being stroked, let alone boosted.
Seems like a good chunk of money for a low reliability system, when a 5.3l or 6.0l could be done for possibly cheaper, with likely higher HP/TQ stock.
11-07-2018, 05:47 PM
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Seems like a lot of work for a little return on the measly 4.0L.
4.0L's barely like being stroked, let alone boosted.
Seems like a good chunk of money for a low reliability system, when a 5.3l or 6.0l could be done for possibly cheaper, with likely higher HP/TQ stock.
4.0L's barely like being stroked, let alone boosted.
Seems like a good chunk of money for a low reliability system, when a 5.3l or 6.0l could be done for possibly cheaper, with likely higher HP/TQ stock.
11-08-2018, 05:31 AM
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Engine: 4.0L 162,000
Seems like a lot of work for a little return on the measly 4.0L.
4.0L's barely like being stroked, let alone boosted.
Seems like a good chunk of money for a low reliability system, when a 5.3l or 6.0l could be done for possibly cheaper, with likely higher HP/TQ stock.
4.0L's barely like being stroked, let alone boosted.
Seems like a good chunk of money for a low reliability system, when a 5.3l or 6.0l could be done for possibly cheaper, with likely higher HP/TQ stock.
At only 5-6 pounds of boost, a supercharger will add +60rwHP and +70rwTQ.
Ask me how I know, there are over 250 supercharger kits out there in the wild and not 1 failure.