Supercharging Problems

AmericanMetal · **Posted:** Fri Jul 08, 2005 6:39 pm

This is for anyone interested in supercharging the 3.7L.
Onelowliberty and KY Liberty I have info for you guys. I contacted Automotion Performance on their intercooled ProCharger System. The reason the 3.7 system never got off the ground was b/c of the 4.7 problems they kept having. The problem lies in the pistons. They kept bending electrodes on the spark plugs and even worse breaking pistons in half. Once they tore the engines down they found the top piston rings were moved up by DCX 1 hundred thousands of an inch. Reason being to clean up emissions, so they found out with some research. There lies the problem, piston domes being weaker. So the moment you have the slightest ping/knock, there goes the piston.
Solution is to swap out the factory piston for a set of JE's or eqivalent. Once they did that the supercharging was flawless. He said the engines have tremendous potential but not with the factory pistons in place. They have the whole system sitting on a shelf collecting dust. All the bugs were worked out for the computer and fuel also.
That's why they scrapped the kit, due to lack of interest but particularly the piston problem. He also stated it's probably why KenneBell did the same thing with their kit.
Personally I'm not willing to tear down a year old engine with less than 5000 miles on it. Maybe once the warranty was gone I'd think differently but for now supercharging takes a back seat. Man I'm bumbed... Wish money grew off my tree in the yard.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

I am either going to have the old block built to handle 150 hp direct ported N2O shot, or for a Paxton supercharger kit. You are right about the stock 3.7 not being able to handle the extra power. I lost mine after a year with the N2O shot when a valve stuck and it blew a couple rings at over 90 mph while making around 335 hp and 400 lbft torque at the engine.

JJsTJ · **Posted:** Sun Jul 10, 2005 12:12 am

KY, what is your best 1/4 mile time w/ that KJ? If you have dragged it that is.

onelowliberty · **Posted:** Sun Jul 10, 2005 2:39 am

Yeah my installer discussed the same issues with me and that's what we're doing in order to correct it so that it runs good. Also we are taking other measures like upgrading various engine pieces for example the pistons and rings along with coating the engine block, porting and polishing, 75lb fuel injectors and so forth. Pretty much no expense is being spared with it. Luckily I am getting sponsored and I too wish I had a tree that grew money!!

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Unfortunately the valve stuck while I was running the first official 1/4 mile. I didn't launch, and the engine shut down at 91 mph and I coasted across the finish for a 15.7 at 78 mph. With a good launch, it should have run very low 14's, or even touched the 13's. No one at the track even realized anything went wrong. At least I beat the KB supercharged Libby's time of 16.1. I need to take the Libby to the track with the new stock motor in it once I get it broken in. With the gears, stall converter, intake, exhaust, and computer, I think I might be able to beat that 16.1 without any juice. I need to find someone to sponser mine. Already got an extra $12k in it, and still need to spend another $8k-$10k to finish it.

AmericanMetal · **Posted:** Sun Jul 10, 2005 1:34 pm

You guys pretty much have it all figured out. After drag racing for 20 years with my 70 ss nova I cashed it in and got out. I just did'nt have the time for it in my life anymore. It put a nice down payment on my jeep and paid off some bills. I was hoping to just be able to buy a bolt on aftermarket supercharger kit and go. I don't really want to yank out a new engine with a little over 4000 miles and start rebuilding everything again. I was looking for the power in aiding me with towing a travel trailer. Not really for drag racing situations. You guys go for it, I'll sit back and enjoy listening to your sucesses.
Since mines a 4x4, a moderately lifted ( 4.5" ) and 33's would make me happy. I've done a Magnaflow cat back, getting ready to fab my out ram air intake system for the cooler charge it will provide. Headers could be an option but I definately want to upgrade the computer. There's gotta be some unlocked HP potential there, even if I have to switch to super at the gas pump to get it. All in all I'd be happy to get another 20-30 horse from these mod combinations. So if you guys have any ideas they'd be helpful ?

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

You should go for some 4.10 gears. You can get aftermarket gears from Yukon with a rebuild kit for around $250. The only place you can get the front gears is a dealership for $450. They will not fit the carrier in the front. That's another $125. Then you need all the parts to rebuild it. You're best off getting a low milage salvage front end from a 4 cylinder. Talk to APS Precision about a custom torque converter set up for you specific needs. I love the one they built me. Don't bother with a piggy back computer mod. B&G Chrysler can flash your ECU with a performance program that actually turns off the torque management. It's great. If you want to upgrade your intake, get the Profinish-Proglass hood and put a K&N or similar filter underneath it. I got 3-4 mpg and a noticeable power increase. I'm using the Borla dual outlet exhaust. I'm talking to some people about headers now. These mods make it feel like it has 4.7 in it. They are all you need unless you're going to the track. That's why my choice of boost in N2O. It's only there for 10-15 seconds. I have to be able to drive this thing every day. It goes on ski trips every weekend during the winter. The performance mods can not take away from it's ability to take me skiing in any way. Racing is my secondary hobby. Otherwise I would have a race only car.

AmericanMetal · **Posted:** Mon Jul 11, 2005 4:52 pm

I checked out APS's site, I like the converter idea. Also checked out B&G, what are they charging to flash the computer and what's the turnaround time ? Lastly the Profinish hood: Does it dump into the K&N setup from the factory or do you have to fabricate duct work to the K&N ? Thanks KY Lib.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

AmericanMetal wrote:

I checked out APS's site, I like the converter idea. Also checked out B&G, what are they charging to flash the computer and what's the turnaround time ? Lastly the Profinish hood: Does it dump into the K&N setup from the factory or do you have to fabricate duct work to the K&N ? Thanks KY Lib.

I bought a spare ECU from Autocraft for $250+$125 core for a total of $325. I sent that to them to get it programmed. I went through KRC Performance to get the B&G flash. It was about $450. Turn around on mine was about a week, but it was also the first 3.7 to get their aggressive flash. It makes a big difference. I just put it on the new engine on Saturday. You need this modification to make the others work. Deleting the torque management is worth it alone. The hood dumps all that cold air through an opening right above the cone for the K&N FIPK. It makes a surprising difference. I gained about 3-4 mpg on the highway with it. That was about twice what I calculated for the cold air affect. It seems to be acting as a ram air system even though I haven't sealed off the bottom of the heat shield.

AmericanMetal · **Posted:** Wed Jul 13, 2005 1:43 am

Sounds good, I've already been saving. Stay tuned cause I will pick your brain some more. Thanks Joe

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Glad I could help. You'll really like it if you do the whole combo. You can also do it in stages as you save up for it like I did. It really surprises my family how much more powerful it feels than my Mom's 2002 4.7 Grand Cherokee Limited and my Dad's 1998 4.0 Cherokee Limited and they've never ridden in it with N2O. It tows through mountains, or carries a whole load of people to go skiing in the mountains with ease. I love it. However, I have a perfectly good rebuildable block laying around, that I'm just going to have to do something with. I'm going to have KRC build it the way I've discussed with Marty. It will be more powerful than the stock engine, and capable of handling at least a 150 hp shot. I already have a lot of disconnected nitrous equipment in the vehicle that I don't want to pull out. Plus a switch to turn it into a 400 hp sport truck really amuses my strange little mind.

onelowliberty · **Posted:** Tue Jul 19, 2005 1:45 am

This is for AmericanMetal or anyone else looking for a sweet k&n intake, check out this dual intake I just ordered off of ebay I'll let everyone know how well it works out.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=38634&item=7986790897

Calvin56 · **Joined:** Fri Jul 08, 2005 1:59 am **Posts:** 345

That is interesting. Now, just get a functional Ram/Cowl induction hood for each side....

YOu might even be able to fab some nice shaker style scoops for each side that could add an original look to the hood.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

You will need to do something to get colder air to them. They'll pull in extremely hot air in that location. That will negate any effect from the increased air flow. You're going to need to do a custom hood.

Calvin56 · **Joined:** Fri Jul 08, 2005 1:59 am **Posts:** 345

All this talk about power/superchargers in this forum is great. I really wish the Libby could have at least had the option for the 8 cyl

I read on the last board that someone had allready dropped the 8cyl (grand?) into their KJ.

The lack of power really gets to me. I need to get some kind of forced induction when I can get my wallet to grow some more green. My 96 Tahoe- 2 door version, 5.7L, 31's, appears to have a much bigger lack of aerodynamic efficiency still gets 20 Miles per gallon, and has more oomph.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Who dropped the 4.7 in a Libby? We were looking at doing a 4.7 HO conversion to mine, but it was going to be very expensive, and a lot of work. Also, if it was in a bad wreck, the motor wouldn't be able to drop.

Calvin56 · **Joined:** Fri Jul 08, 2005 1:59 am **Posts:** 345

It was a side note in another post on the old boards. Someone overheard another customer at a dealership saying he needed a part for his libby, but he went on to explain that he had replaced the 3.7L with the 8 Cyl.

KY Liberty · **Joined:** Sat Jul 09, 2005 1:46 pm **Posts:** 1195

Onelowliberty,

How goes the supercharger install? I'm anxious for some dyno #'s, and a seat of the pants dyno report. I have to decide between a big shot of N2O, or supercharging with a cheater shot, to know what compression ratio to have the motor built with.

AmericanMetal · **Posted:** Wed Jul 27, 2005 10:37 am

I'd like to hear about it too...

KY Liberty, I hit B&G's site again. I notice they have different flashes. The first one seems the most basic but doesn't turn off torque mang. The second one is the one that turns it off but mentions something about an M1 manifold ? When I spoke to Kenne Bell about their programing a while ago they said nothing about the torque mang. but did say I'd have to swap out my t-stat for a 160 deg. Bell also stated theirs re-mapped fuel, spark, fan cooling, trans shift points which I'm sure the B&G flash does too ? Bell told be I'd have to stop using 87 octane and switch to 91 octane. Did you switch your t-stat out for a cooler one and up your octane for the flash from B&G ?

I notice you said you went throgh KRC for the flash, was there a reason you did'nt got directly to B&G for it ?
I've got the Magnaflow cat back on the Jeep now. I at least want to get the K&N KIT b/f I get the computer flashed by someone. I'll definetly upgrade to the pro-finish hood for the cool air and upgrade the converter at some point soon after. This way it all comes together. Once Superlift comes out with their 4.5" kit and I can go to 33" tires, I'll have no choice but to upgrade to the 4.10's that you spoke of. Got a lot to do and spend for that matter...

SVEN90BUCS · **Posted:** Wed Jul 27, 2005 3:39 pm

onelowliberty wrote:

This is for AmericanMetal or anyone else looking for a sweet k&n intake, check out this dual intake I just ordered off of ebay I'll let everyone know how well it works out.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&category=38634&item=7986790897

OLL (onelowliberty)

:

Did you install the dual intake yet? Any issues with re-fitting the air flow sensor? How about the overall fit when you close the hood?

KY Liberty:

What about extending the tubes? Would this solve the amount of hot air flowing in the intake/

Sorry, I'm not mechanically savvy.

Supercharging Problems

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