LN2 Super Charging - Performance Forum

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LN2 Super Charging
Saturday, October 25, 2014 12:00 AM
I\\\'m wondering has anyone ever ventured into trying a supercharged Ln2? I imagine it would all have to be done custom. I would like to try it depending if with the layout is even possible. The easiest way I can see to try it is possibly take a vortec/procharger style kit custom fabricate a bracket and place it where the a/c compressor would be, I already don\\\'t have one in place so... that\\\'s my first choice of placement. The only other way I can think to go about it is to make a custom intake manifold that accepts say the m90 charger from the 3800 series v6 motors and remove the power steering pump to give access to the belt.... As of now this is just an idea, but any one who would be interested in experimenting/helping me make it a reality would be greatly appreciated. Any thoughts, ideas, concerns, or advice?

Re: LN2 Super Charging
Saturday, October 25, 2014 11:57 AM
This came up a few times over the years that I remember.

The old phrase \"anything is possible with enough money\" is pretty much the only thing here thats worth saying. I\'d venture it would take more hp to drive the blower than its worth because the LN2 is pretty weak off-boost without extensive work.

My advice would be to turbo the motor instead. Better net gain in power with less boost than a supercharger would need; and far less money.

If you want a supercahrger; a pro-charged setup would be best. The m90 would be cheaper initially compared to a good centrifugal blower; but making an intake to accept and m90 would cost a lot compared to a bracket to hold the procharger.

Another option is a remote m90 setup in the same place on the front of the motor but with a header you will start running out of room and the heatsoak in that area would be quite significant.

Both of these are options that I considered way back in the day before doing a turbo setup.

If you\'re gonna do it though; Pro-charged is how I would do it, right where you are already thinking. The a/c spot. Lots of thread bosses in the block for bracketry down there too.

\"A car just isn\'t a car without a little blood, sweat, and beers.\" -- Shadowfire
Re: LN2 Super Charging
Thursday, October 30, 2014 4:05 AM
To the best of my knowledge no one has ever finished a build. I have helped a few people with pulleys. The closest to finished, was a LN2, that was charged using a vortec supercharger mounted in place of the AC compressor. He had all the parts. Was on a silver Sunfire. I do not think he ever finished all the fab work, and sold off everything.

The other used a M62, and also mounted it down in place of the AC compressor. He purchased a snout that bolted to the 4 bolt output of the supercharger, and was planing on plumbing it like a turbo. BOV, Intercooler and all. I believe he ran out of money, and sold off the parts and scraped the car after he found a lot of rocker rust.

There is a S10 with a LN2 running a M90 in a similar fashion. He did frequent the forum a few years ago.

PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Re: LN2 Super Charging
Thursday, October 30, 2014 4:42 AM
Right now I am just entertaining ideas on the setup. I have already invested in a high comp rebuild, but with low boost from a s/c I might try and invest into the idea depending on whether it would be possible to run it or not..
Re: LN2 Super Charging
Thursday, October 30, 2014 5:24 AM
If I'm not mistaken there was a vortec setup for the LN2 S-10's back in the day. I remember someone on here trying to adapt it to a J but I don't think it ever go off the ground. With the amount of custom work it would take you would be far better off going turbo. I understand the doing something never been done before but there comes a moment when it just isn't practical. Turbo LN2's are tried and tested and there is more than enough info and parts out there to make the process pretty easy.
Re: LN2 Super Charging
Thursday, October 30, 2014 7:15 AM
Money vs gains you'd be better off turbo.

Properly sized you'll have minimum lag and make respectable power.

Re: LN2 Super Charging
Friday, October 31, 2014 9:17 PM
It's already decided, I have a rebuilt motor done and ready for pickup that's high compression. Otherwise I'd have gone turbo. It's just and idea for the future that's unique. I'd like to find out who had those brackets fabbed up for use in place of the a/c though. I was contemplating getting the custom intake done though cause its on my list of future upgrades anyhow, just guess it depends on how much extra to fab the s/c onto the plenum of the intake... and whether or not the TB would fit in the engine compartment...
Re: LN2 Super Charging
Saturday, November 01, 2014 8:09 PM
So high compression is bad for boost due to detonation... Note I said BOOST not Turbo or Supercharged...

And what "High"?

a OE N54 is like 10.2:1 and is turbocharged... Just takes proper tuning.

'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: LN2 Super Charging
Sunday, November 02, 2014 9:42 PM
not entirely certain what the ratio is... Im rebuilding the pre 98' engine with 99' and up pistons... Some of the guys say it skyrockets compression to close to 13:1 and others say its only on the high side of 11:1 nearly 12:1.... I know some engines can use high compression with boost... be it turbo or supercharged... newer Mazda's have 12:1 - 14:1 with a small turbo only boosting a few psi and makes over 200 hp stock.... but being as the ln2 with low compression can handle up to 300hp on stock internals usually at pretty low psi somewhere in the range of 6 - 10 psi (varies, but these are some #'s ive been told).... I cant imagine that high compression with a super charger would likely hold up too reliably for weekend usage, let alone daily usage. Oh, fyi I have bought ARP studs for the rebuild because last time I swapped those pistons in it blew the head gasket and cracked a piston with stock head bolts... hopefully the studs will remedy that problem.... If I could get some help with where to start off and where to get some materials for fab work... assuming that it would be a good idea to try it... worst case scenario I just switch out belts and not run the s/c.... I would like to finish this idea off and be the first completed s/c ln2 cav.
Re: LN2 Super Charging
Saturday, November 08, 2014 7:27 AM

I dont think cracking a piston had anything to do with head bolts...

'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08

Re: LN2 Super Charging
Saturday, November 08, 2014 10:16 AM
Stock compression 26* timing and ~35 psi boost from a gt35 and I didn't knock.

I'm sure the DCR of that is higher than what a blower on 11-12:1 will do.

It's heat that causes issues and poor tuning no matter the pressure source. The motor doesn't care how it sees boost just how much air and how warm it is when it comes in.

"A car just isn't a car without a little blood, sweat, and beers." -- Shadowfire

Re: LN2 Super Charging
Saturday, January 17, 2015 10:31 PM
From what I'm seen... it's sharp edges on the piton & combustion-chamber faces, along with heat seen as result from compression pressure--in addition to inlet-charge & engine-operating temperature--that cause detonation. That along with spark-timing, somewhat.

I say that with this in-mind:

Some time back, a fellow from Florida wrote about how he was driving his all-stock 'Deuce J-car when he experienced detonation during off-idle "breakaway" (From a dead-stop) acceleration. Further talks with him showed his operating-temperature during this incident to be at 220*F, with the day's air-temp in the upper-90s. Plus, he was running 87-octane fuel! Now, having had both an older & newer 'Deuce'd S-trucks w/auto, I know just how tempermental this engine is when it comes to the octane of fuel run through it when a given load is applied... So I can tell you like I told him: This engine is only rated to run on 87-octane for emissions mandate-related reasons, and only runs best in all apps (J-car, W-car & S-truck) on gasoline with a 90-point octane rating or higher. Simply put, I told him to try running "89" or higher, and his troubles would instantly disappear.

So in-short: It's really temperatures seen during compression that cause detonation... with a given octane-rating of fuel being run.

Go beyond the "bolt-on".
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