Cheap Horsepower Real Easy!!!!

scottewid · 01-18-2001, 03:55 PM

Well, I've done it: Nitrous Oxide on my 1984 944 na. Now I know you're thinking "..the fool!!! He's gonna blow his engine!!! First, though, I'd like to say thanks to Porscheboi, fellow bottle feeder, for you advice on my previous nitrous posts!

Secondly, I'd like to say: My ooooh my, does it exceed my wildest expectations!!!! This is truely horsepower in a bottle for dirt cheap and 6 hours of install time, if you take it slow!

For all you 944 na'ers who know that your car has all the potential it was designed for, but is horsepower/torque challenged, and have thus started dreaming about turbo transplants, Rimmer Supercharges, and the LT1 V8 coversion, I have to urge you reign in those costly and involved fantasies. First, give the bottle a try, and if your power lust isn't satiated, then I say GO FOR IT on all the above mentioned exotic mods!

I paid $419 at Carparts.com for the NOS 05123 EFI dry system. I also purchased an extra 10lb nitrous bottle and bottle warmer (the nitrous bottle should be 85F for best performance), for a grand total investment of $750. My 1984 na is bone stock. This was the only performance mod and it was the easiest 6 hour install of my life.

I was a little nervous about testing it because if you don't have enough fuel flow to compensate for the extra oxygen pumped in with the nitrous, you're gonna go real lean and maybe hole a piston. The kit increases the fuel pressure to richen the mixture, but I adjusted the DME to the 6% rich setting, just to be safe and filled up with 93 octane (I usually run cheapo 87 octane).

The nitrous kit has a wide open throttle switch and only kicks on at WOT. You should also only engage at 2500 RPM or higher.

I tentatively took it out tonight on a side street and kicked it in..."hmmmm", I thought, "seems pretty peppy, but not quite what I would have expected..." So I took it home for the requisite spark plug inspection (to make sure you're not burning too lean) and discovered the solenoid groud wire came loose. Turns out I wasn't injecting nitrous afterall! That fixed, I went out again, being sure to stay within 1/4 mile of home in case I blew up the engine...

Accelerated fairly sedately in first without hittin WOT, shifted to second, watched for 2500RPM at 3/4 throttle, floored it and accelerated as expected for the first half second...then the old "butt dyno" registered something big time different! I've never driven a 944 turbo, but I've got a Saab 900 turbo, and this rush definitely felt like turbo kick! The engine also whined at a much higher, but not at all offensive or alarming pitch! Shifted to third, screeched the tires, and was at 75mph before I knew it. Not the slightest hint of detonation or pinging, overheating, or otherwise undue stress on the engine! This was with the 60 horsepower jet. The kit comes with a 75 HP jet also. Took it home, checked the plugs and they're clean as a whistle: no evidence of preignition.

Bottom line: I'm mucho impressed at the performance I've gotten for $700 and 6 hours of labor. I've never driven a 951, but I'd reckon this mod puts my na close to the acceleration potential of the turbo (using only the 60hp jet!). There's not the slightest hint of any adverse affect on my engine, which makes sense since I'm only running a 60hp shot (143+60=203hp), and our na's have the same bottom end as the turbo. Each ten pound bottle of nitrous supplies about 3 minutes at a 60hp jet....not bad since most of my WOT sprints last only 15 to 30 seconds at most. Give it a try before you invest in other costly mods. If you don't like it, it can be unbolted in an hour or less, leaving no evidence that it was ever installed.

p0r2chby · 01-18-2001, 04:23 PM

So, where did you put the bottle

drew1 · 01-18-2001, 04:55 PM

This is real interesting.

1.2gees · 1.2gees's Garage

The bottom is not same between the two cars...

The crank, and bearings are the same. The con-rods, or the pistons, as well as a load more are different.

However I don't think NOS is such a bad idea at all, and if it were as easy to get a bottle as a fill up of the gas tank (and as cheap), I think a lot of people would be using it.

A properly installed NOS kit is indeed a pretty safe, and cheap way to increase power, just make sure you don't go overboard. +25hp is fine, so is +50hp, but ofcourse +200 I don't think would be.

Whatever the case, make sure you get enough fuel in, and use proper gas, I'd ratard the timing a bit just to play it safe.

I'm sure there's some way you can hook up the system to only kick in (and kick in gradually) above 2500rpm, and past 3/4ths throttle.

Good luck with your car, and keep us updated.

Pictures would be nice too...

NOTE: don't skip any oil changes, or other regular maintenance, but most important of all, DO NOT slip the clutch, when on NITRbOoUSt

Ahmet

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It's all the driver...

scottewid · 01-18-2001, 06:18 PM

I mounted the bottle in the passenger side wheel well storage area. It sticks up about 6 inches above the floor of the hatch, but is still easily covered by the carpet by leaning the carpet against the side of the bottle. I ran the hose from the bottle along the fuel lines, under the car, and held it up with nylon zip ties.

Ahmet, thks for the info: I always thought the 951 had the exact same motor, other than head. I still need to do some more experimenting (this note was based on my intial test thrills!!) I'll stick to the 60hp jet for a while and it certainly seems I'm getting enough fuel in for it and stock timing is OK. I'll test the 75hp jet when I get the nerve, and will change the DME to rich 6% and timing retard 3 degrees for that one, but I'll never go any higher than 75hp. Oil's good, I've always done synthetic at 4500 mile changes.

I'll take some pictures of the install and post them in the next week or two. On that point: How do people put actual pictures on this board? I can upload them to a server and put an address, but I've seen other folks' posts with actual pictures....
thks, scott

scottewid · 01-18-2001, 06:24 PM

Ahmet, sorry, forgot to mention: there are "progressive nitrous controllers" that bring the boost on gradually through the RPM range, so you don't have to worry about watching for 2500, but their mucho expensive and I'm just starting out. Given my budget, I'll just have to watch the tach, rather than shell out the bucks for the auto boost controller.

944slide · 01-18-2001, 10:21 PM

How do you adjust the timing and fuel mixture with the DME?

Porsche 951 Fanatic · 01-18-2001, 10:35 PM

There is a knob on the DME someome was talking about it in another post.... about umm.... unleaded fuel....

944slide · 01-18-2001, 11:43 PM

Thanks! I found the information and will attempt this modification. Seems there was a person whose 944 did not pass California smog, retarding the timing may help him lower the NOX levels.

awilson40 · 01-19-2001, 07:34 AM

How much does it cost to fill a bottle?
Where to you get yours filled.
My boy is wanting to try this on his 240sx

Tentster1 · 01-19-2001, 08:50 AM

Scottewid, any way you would be willing to share e amail addresses with me so I can get more info on your conversion. I may attempt the conversion in a week or so. Thanks. Otto.

Tentster1 · 01-19-2001, 09:11 AM

Scottewid, did you pay 419. or 519., cause i just checked the online catalog and it shows 519. for #05123, just wondering if they bumped up the price recently, or?.Thanks.(Topss999@aol.com).Otto.

porscheboi928s/c944t/n · 01-19-2001, 11:19 AM

Congrats! scott.(what size jets ur using?).. i gained 100rearwheel hp on the chip/comp. tweaked and juice alone..287.3 rearwheelhp..with 13 psi.boost(dynoed).stock is 180rearwheel hp..... have raised it to 15psi and its sweet(not dynoed yet)..will be raising the boost to 21 psi. again to achieve 300 rearwheelhp.bear in mind that everything is stock(no adj.fpr. or wastegate)..if ever i get the funds i will get a 60-1 upgrade for my k26(i'm not trying to show off here)just giving ideas to everyone whos interested..

how does a 300 rearwheel hp. sound??