3.8L and supercharger
JK Enthusiast
Joined: Nov 2009
Posts: 325
Likes: 0
From: Christchurch, New Zealand
I've had my RIPP on for a few months now and am happy. Dyno'd before and after and got about a 50% gain to both hp and torque. Had a custom air box made to plumb my snorkel in but rest of install went well. Does save a bit of fuel normal driving but certainly can use more under hard acceleration. NB right hand drive
JK Freak
Joined: Nov 2008
Posts: 510
Likes: 0
From: texas
Another approach to estimate how much power RIPP's dyno should have reported for the stock engine if it had run to redline is to look at it in terms of percent loss compared to crank numbers for the engine.
At the crank, the Pentastar in the Wrangler is rated for 285 hp and 260 ft-lbs torque.
RIPP did capture the peak torque of the stock engine at about 240 ft-lbs, which is 7.7% less than at the crank.
7.7% less than 285 crank hp comes out to 263 hp at the wheels. Wow... that actually matches my previous estimate exactly!
Something seems fishy about seeing only 7.7% drivetrain loss on the dyno for a Wrangler.
At the crank, the Pentastar in the Wrangler is rated for 285 hp and 260 ft-lbs torque.
RIPP did capture the peak torque of the stock engine at about 240 ft-lbs, which is 7.7% less than at the crank.
7.7% less than 285 crank hp comes out to 263 hp at the wheels. Wow... that actually matches my previous estimate exactly!
Something seems fishy about seeing only 7.7% drivetrain loss on the dyno for a Wrangler.
JK Newbie
Joined: Nov 2013
Posts: 60
Likes: 0
From: RSA
more like
on an auto 3.8 i think drive train loss is more like 30% usually leaving about 140 to 150 hp at the wheels stock. take a look at the dyno in the previous post. its showing about 100kw stock which comes out at about 134 hp at the wheels. stock its rates 202 hp or 150kw at the crank. about a 30% drive train loss. given that only the major change in drive train in the 3.6 is the auto is seems extremely unlikely that this is enough to turn a 30% loss into 7%. something fishy indeed.
Last edited by SAJK; May 7, 2016 at 12:18 AM.