Need exhaust kit suggestions for power/air for supercharger added exhaust.
Need exhaust suggestions for 2016 Sahara Unlimited with Edelbrock E-Force supercharger
- Thread starter Jcsushi
- Start date
Did you drop in new pistons to lower compression
before adding supercharger ?
before adding supercharger ?
No, I took it to a performance shop and that was not suggested or recommended.
That's not necessary.
The conventional wisdom is that lower static CR and higher boost makes more power. And this is true. Sort of. Sometimes. Except when it's not.
If you're talking about peak power, then this build strategy is great. This is how race engines, which operate in a very narrow RPM range are built. You will see people running 7-8:1 static CR and sky high boost numbers. On the dyno, you will see a powerband that looks like Pikes Peak. Now that's great, when you can selecting transmission and differential gearing to keep the engine in that high-RPM peak all the time. And keep in mind that these low CR/high boost engines are running race gas. The last time I checked, 112 Octane race gas was about $18.00 a gallon.
But for a street driven car, that's no good. You need a wide powerband if the vehicle is going to be streetable.
This is an old chassis dyno sheet from my Corvette. The red lines show why the LS is such an amazing engine. That pull was done with the stock LS1 plus Texas Speed & Performance longtube headers, a Cold Air Intake, and a tune. Let's look at those numbers.
The stock LS1 made 345HP. A chassis dyno will read lower, because of power used to turn the transmission, driveshaft, differential, wheels, tires... I think that's the most reasonable number, because what ultimately matters is how much power you're putting to the ground. But manufacturers always report the higher number from an engine dyno. Not unreasonable, since that number will apply to all engines, but the RWHP numbers will vary depending on the transmission and such. Driveline loss is accepted to be 15-25%, with automatics losing more. My vette is an M6, so I use 15%. That results in the lowest reasonable crank HP figure.
So my mostly stock LS1 made 331HP at the wheels. That works out to 390HP at the crank, 45 more than stock.
The stock LS1 made 350lb/ft of torque. Again, that is at the crank. Mine was 334 at the wheels, which (with the 15% loss) works out to 393lb/ft.
But here's the thing. The torque curve looks like a table. You have 300+ lb/ft of torque from just off idle all the way to redline. That is what makes a streetable performance engine.
Now look at the blue lines. That is a stock-internal LS3 with ported stock heads, roller rockers, doubled valved springs, a cam swap, a Vortech V3Si running 10lbs of boost, the same headers, Random Technology High Flow cats, SLP Loudmouth resonators, and a Magnaflow muffler. Using the same 15% driveline loss, that works out to 834HP/711lb/ft. The torque curve is no longer a table. That is unavoidable with a boosted engine. But it's still pretty flat. You've got 400lb/ft from 2000RPM on up. That makes a car that is mild mannered and totally fine on the street, but will take off like a bullet at any time, from pretty much anywhere in the RPM range. And bear in mind that this is a pump gas tune. Yes, it's premium, which here in the mountains is 91 octane and goes for about $4.50 a gallon. I can run lower octane, and the computer will pull timing. Ick, but I can.
This is a car that runs a very traction limited 11.9@123 at a DA of 8800 feet. In exactly the same state it's driven on a 4000 mile road trip. Not even a tire pressure change. You will be comfortable on that road trip, with the AC running and the modern infotainment center streaming music or playing a DVD.
That LS3 is currently out. One of the (stock) piston skirts collapsed after about 400 trips down the strip. Just back from the machine shop. We're going to drop the static CR from the factory 10.7 to 10.0 and run a bit more boost. The further down this low CR/high boost road you go, the more peaky the torque curve will be, and the less drivable the car will be.
Ok fair enough that it wasn't suggested to you .
I'm going to be 100 percent honest . So please
dont think I'm trying to be a douche .
Generally an engine is designed around
a Supercharger or Turbochagrer .
What I mean by that is the combustion
chamber pressures increase significantly
with the added boost of a SC or TC..
This puts signicant more strain on the
Pistons , Rings , connectzing rods, valves ,
rockers , lifters etc .
Quality engine builds that can take the
punishment include Forged Pistons ,
Forged Connecting Rods , chromoly rings .
Dropping compression by 1, or 1 1\2 digits
goes along way to reducing detonation and
minimizing stresses on the engine components
increasing reliability .
Edelbrock has been around a long time .
I used their intake and carb in a 71
Mustang Mach 1 build . . Quality manufacturer.
Thing is why are many Jeepers doing LS
Or Hemi swaps when adding a supercharger
could get you the same power?
It's cause the 3.6 would need to be built .
From the factory it wasn't designed to be SC or TC .
I realize you spent a lot of money . Your obviously
going ahead reagardless of what I type .
If possible run less boost . It will save
your engine . If your hammering on it
will end up just like lite brite and many ,
many others in 3 months . Putting a
rod through the block or disintegrating
a piston .
Watch the link . They are legit .
Added turbo charger and couldn't
get it to run right for 3 months
than blew a rod .
Little silly talk in beginning of video
but be patient , it's a good learning
tool .
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I saw your follow up. Your concern seems to be about the engine holding up?
The LS3 in my Vette lasted 70,000 miles. Including a couple dozen track days, several 4,000 mile road trips, and 400 blasts down the drag strip.
Moderate amounts of boost on daily drivers that are not being thrashed at the track is typically just fine.
Nobody is doubting the performance or reliability of
LS engine . They are an amazing high performance
motor . The LS 3 has 6 bolt mains , I think nodular
crank, forged pistons and Rods . I remember reading
somewhere the LS3 bottom end can handle up to
1K HP.
Thing is we're not talking about an LS 3.
We're talking about a Jeep 3.6. It's an
entirely diff motor and def not even in
the performance category
I do hope the OP does at least comsider
swapping pistons , rings and Rods
It would go a long way to ensuring you
get a good life out of your motor
and supercharger . Reliability is
important . Anyways didn't mean
to derail your thread . Hope you
get exhaust figured out .
I'm certainly not looking for advice "what I should have done differently". I'm sure there are hundreds who would like to call me an idiot and whatnot. I'm just looking for someone with knowledge in the area, particuarly with Jeeps, ideally but certainly not necessarily. And even more ideal with be a Jeep owner or mechanic with the Edlebrock 1528 E-Force Supercharger and what exhaust upgrade they went with.
Thanks again for the input. I'm torn, for now, to either add new cats, loop delete, Borla S-Type Cat Back Part# 140644 or just add the Borla, leave cats as is. I spoke to Edlebrock and they recommended to leave the cats so I don't have to pay to re-tune. I have been reading about buying a tuner, so many options vs spending 1k-1,500k to re-tune. Also, i'm in NM- they don't monitor emissions, several have just said run dirty. I would even be interested in going true dual exhaust however I understand it's tricky due the gas tank position as well as drive shaft. I sell homes, I'm certainly no mechanic.
I got a great deal on the SC- $6,100 new and $1,200 for install, locally. I want to drive it for 10 more years but don't want to spend more than needed at this point. I'm a street driver, I do very little offroad as this is my daily driver. I'm adding new plugs this weekend, hoping to get more than 14 miles to the gallon. I'm laying off the throttle now until I decide what option to take. More air is my engines friend, I do understand that.
I'd swap in high flow cats. Emissions may not be monitored, but leaving your grandchildren with breathable air is a Good Thing. There is no significant HP gain from removing the cats, and you can make all the power you want through good high flowing cats.
I wouldn't bother with a true dual. That 3.6 (even blown) isn't going to need that much exhaust.
This had a blown 383 stroker LT1 and made about 600HP through mid-length headers, a single high flow cat, and a single 3.5" exhaust.
That's a really good deal. If you're not thrashing it, it should last you a good long time.I got a great deal on the SC- $6,100 new and $1,200 for install, locally. I want to drive it for 10 more years but don't want to spend more than needed at this point. I'm a street driver, I do very little offroad as this is my daily driver. I'm adding new plugs this weekend, hoping to get more than 14 miles to the gallon. I'm laying off the throttle now until I decide what option to take. More air is my engines friend, I do understand that.
What did you do about spark timing under boost?
Delete the cats and run a sparkplug anti-fauler for your downstream O2 sensor. This will trick the ECU into thinking everything is OK. No need to retune. I did this to my Saab when i ran 3" pipe straight from the turbo. The downpipe did have bungs for O2's. I needed them for Emissions. As for your exhaust, What size is recommended for the supercharger? Maybe a custom exhaust shop would be your answer?
