i want to slap a supercharger onto my stock engine. My stock compression ratio is 9:1. How much boost can i be running with pump gas?
I'll retard ignition timing and an intercooler.
I would optimally want to run about 5-6psi of boost. Is this possible on 91 octane pump fuel without dropping compression?
I want to slap a supercharger onto my stock engine. My stock compression ratio is 9:1...
Lincoln Reyes
Jack Sanders
What engine? What heads? What car? What further cooling mods? What kind of supercharegr (roots, twinscrew, TVS, centrifugal)? 91 octane, sure, but RON, MON or AKI? What do you have to tune it, and back off the ignition timing?
Jack Price
engine is a 3 litre 6g72 24valve making 177hp
eaton m62 roots supercharger to make about 5-6psi of boost
greddy intercooler kit from a wrx will most likely be used, however i'm open for other options
91 octane premium fuel is 95ron
ignition will be retarded with a reflash
Angel Gonzalez
Why not turbo
Zachary Brown
Because piping on a transverse V6 is a bitch.
How in the hell are you putting an air to air intercooler between the supercharger(sitting in the V) and the engine?
Anyways, you won't need the intercooler, you can get away without one on boost that low. If you realyl want to lower the IAT's, I'd consider a chemical itnercooler instead (water/meth injection) and making two seperate tunes for that: one with, and one without the water/meth.
Octane should be good enough, although I'd also consider E85.
Camden Cox
don't you have 93 where you live? that would be better. mitsu dropped compression to 8.0 when they went fi on their v6s
Jace Williams
it's mounted longitudally. Reasons for picking a supercharger is I just like superchargers and torque from the bathypelagic.
the 6g72tt has truckloads of boost and i was wondering if I could get off with low boost and throwing more fuel into the mix+retarded ignition timing.
A 20% increase in hp would be sufficient for my needs as long as the truck can keep working as a daily driver. We don't have e85 and 93(98 ron) just seems not worth the measly 20% increase in hp.
Jose Nguyen
use modern fuel injectors that atomise the fuel well, and a a pair of decent headers and you might be okay
Luke Edwards
20%? Shit, you'll get away with regular fuel and still get a 40% increase. E85 + water/meth, and you'd be looking at 55%.
Oliver Clark
I was calculating it like this:
175hp minus about 15hp of parasitic loss on the supercharger
160hp/15psi=10.6(66)hp per psi
15psi plus 5psi of boost gives us 20 psi
10.6(66)*20=210hp
175hp/210hp=21% increase in horsepower
but my calculations also give me a compression ratio of about 12:1 if I boost 5 psi into an engine with a compression ratio of 9:1.
Lincoln Rogers
You'll get away with 6PSI, and you'll probably ge tmore than your 20%.
Jason Hill
6g72's hold fuckloads of boost
Headstuds and a thicker head gasket and you can hold at least 450 crank hp
Tyler Adams
i don't wanna fuck with the quench. I'll be looking for lower compression pistons after i install the m62. I'm going to take the tuning step by step.
i don't want to add a piggyback ecu and a 7th injector before 6-7psi, which I'm not going to do with a compression ratio of 9:1.
The part about the engine reaching stock RPM sounds like a bullshit claim tbqh. The redline on the 6g72/74 is about 7k rpm. Only way i see that is if they just keep throwing more and more fuel into the increasingly innefficient mix to prevent detonation at higher revs. Lowering the rev limiter is a must at that level of compression.
Lucas Baker
how is this correct?
Robert Cook
HP / atmosphere pressure x atmosphere pressure + boooooost.
Dominic White
Since an atmospheric engine is producing X horsepower at 15PSI of pressure (atmospheric pressure), you can divide by that 15, and then multiply by 15+ however much pounds of boost you can add. This usually roughly works, assuming no temperature difference. Since compression creates heat, you end up with an optimistic figure, so take that into account.
Boosted HP = (N/A HP divided by 15PSI) times (15PSI + Boost pressure)
Jose Powell
but how did you calculate compression after boost?
12:1 cr is alot for 5psi, no?
Juan Gonzalez
5/15 = 1/3 more compression.
Static compression is 9:1, add a third of 9 (3), you end up with 12.
So yeah, the maths kinda make sense.
Xavier Roberts
what do head studs do to prevent detonation?
Jose Edwards
They don't, they keep the thicker gasket from blowing out. The thicker gasket reduces compression, which prevents detonation.
Brayden Myers
Methanol injection is a bit extreme for a daily driver truck.
The only problem with air to air intercoolers is when driving at slow speeds for extended periods of time as in offroading there will be minor heatsoak, but i didn't think it was relevant for 5psi of boost.
Intercooler would be placed in the same place the 4m41 intercooler is on the 4m41 bracket.
Water intercooler is an option I'm looking into, but currently I don't think it's worth all the extra hasselhoff.
The m62 is a kind of small supercharger, if it were the m90 i would definately skip the intercooler but having a small unit would give me some peace of mind.
Already installed a 3,5mm powder coated custom skid plate to protect any intercooler I put in.
Ian Wilson
You can buy methanol in bulk for about $2 per gasoline gallon equivalent. It's 105 AKI and gives you an intercooler effect as it's injected, boosting power even further.
Kayden Garcia
also wanted to ask if there's reason to have a bypass valve when running under 6psi of boost?
Nolan Baker
Yes, so your supercharger freewheels under cruise conditions, improving MPG.
Cameron Walker
isnt the m62 too small for a 3 litre engine?
I would be looking at the m90 in your case