KY Liberty wrote:
streetKJ wrote:
I think intake, headers, and exhaust will only free up horsepower, but not really give it.
Our KJs make 210hp, and if you factor in power loss through the 4WD drivetrain, its about 25% power loss rather than the standard 10-15% loss in 2WD drivetrains (4x2 KJs are excluded from this), which would mean we put out roughly 157.5hp at the wheels.
Say you add a cold air intake (13hp for AEM i think), JBA headers (roughly 10hp), and exhaust (19hp for the Magnaflow bolt on [or was it 22hp]), lets recalculate with 25% drivetrain loss. You're looking at about 210+13+10+19= 252. About 189hp at the wheels.
Lets say you're supercharged with the Kenne Bell kit, start with 252+100hp forced induction. 352x.75= 264 wheel hp.
I'm dreaming, but that would be nice, haha. We still need forged pistons and connecting rods.
You're right about the automatic with 4x4 losing around 25% to the ground. Around 20% at the transmission, and 5% at the transfer case. The 3.7 V6 4x4 auto makes around 155 hp on a Dynojet dyno, which is the most popular brand here in the US, probably because it reads about 10% higher than the Superflows, Dyno Dynamics, and Mustangs.
Your calculated 252 horse power is too high. With those modifications, you might be at 225 -230 hp at the motor, or around 170 hp at the ground on a Dynojet. Around a 10% increase for under $1500 isn't bad at all.
The supercharger kit from Kenne Bell isn't made. The 3.7 cannot withstand a supercharger for very long unless it is built with different pistons, rings, and rods. Also, the KB supercharged Libby only ran the quarter in 16.1 seconds. Mine outruns it without N2O and the spare stock motor in it. With the N2O it was over 2 seconds faster. After a year with the N2O, the race motor finally blew the headgasket at cylinder 5. It still ran a 15.7 even though the motor was only running for the first 3/4 of the run. Getting ready to have the race motor rebuilt with ceramic coated pistons, forged rods, higher compression ratio, and a direct ported N2O, etc. Should be really surprising to the Japanese vehicles at the track.
Interesting.
I've been reading some of your older posts for a while, and always wondered about some of the mods you had on.
I was wondering about your TransGo shift kit. What does it do exactly? The website wasnt much help at all. Could you also please tell what the APS stall converter does, and how are 4.10 gears beneficial?
I thought Kenne Bell did in fact make a supercharger for the KJ for a short period, but then discontinued it from a lack of demand? Do you by any chance know what PSI the Kenne Bell libby was running when it did that 16.1sec pass?
I'm interested in eventually supercharging the KJ, but of course after much research on getting forged internals for it. It's going to be very expensive regardless. Would you mind posting about your experience in getting your new pistons, rods, and tuning? I'd love to hear about it. I was also looking into possibly using a custom Squires turbo kit (external turbo setup, no intercooler) which will cost about $4k for the turbo kit and custom piping, and doesnt include prepping the motor for forced induction.
I'm hoping they release a stroker kit sometime in the future. If forced induction tuning proves to be too much strain on the wallet, I'll probably just end up tuning it for NA. A friend of mine recommended getting an APEX-i SAFC computer to help control the air/fuel map along the powerband. Couple this with dyno tuning for the SAFC (super air/fuel controller), and the motor's efficiency can be maxed out for a particular scenario.
Since you seem to be into drag racing, I wonder why you didnt instead pick up a set of Koni Yellow (3 way adjustable) shocks and Eibach Pro Kit springs for the libby? Do the Monroes lower the KJ, or are they just the right price. Rather than lifting my ride in the typical Jeep fashion, I think I'm going to get the Eibach pro kit eventually.