86 951 Driver

I know the K26/6 is limited in how much air it can flow, but is it also limited to how much power the engine can make?

I just had a random thought the other day about throwing a 75 shot of nitrous on the car. I tried to do a little research on the google machine, but didn't find much useful info. Most of the info was "BRO, your car will blow up" or "You can only use Nitrous to spool up a large turbo". Could nitrous be used to make more power over what the stock K26/6 turbo can provide?

Scenario: You have a k26/6 car making 240 WHP, but would like 300 WHP. Could you make up the difference with a 75 shot of nitrous?

Dougs951S

Nos in a way cheats the airflow limitations because it brings its own oxygen to the party. So the short answer to your question is yes, you can slap a shot of giggle gas on top of your k26 and it wont blow up IF, and this is a huge IF, you have the fuel and tuning to account for it. Some random chip will not suffice, you will need fairly precise control over your ignition timing and fueling. Make sure to add fuel, and pull timing when the shot comes in and don't hit it before 3k rpm and at anything less than full throttle. Ours cars are low compression and actually take nitrous pretty well. Be prepared to make some SERIOUS torque though. Nitrous generally makes 2-3 times more torque than hp for a given shot size. What I mean by that is giving a 240 whp car a 60 shot to take it to 300 whp will also give it an instant additional 120-180 ft lbs of torque. Be careful and have fun. A well tuned k26 car with a good sized shot on it can easily make 450+ ft lbs at the wheels, and you'll boil the tires in lower gears. I'd run the car on E-85 myself if I were planning this, and would have 80 lb injectors and a good, larger than stock fuel pump.

Edit: Oh and be sure your clutch is up to the task, the factory clutch will not handle a 75 shot + higher than stock boost and will slip.

reno808

LOL

txhokie4life

Torque ~= 5252* HP/RPM

-- so what you are saying is that if you get a 33% HP boost at 3000RPM

However that means that you will see a 2.3x boost in Torque at that same 3000 rpm.

Mike

86 951 Driver

Why so funny?

Jfrahm

There can be great synergy between NOS and boost due to the cooling effect. Your timing map might not be optimal.

reno808

....

odurandina

my thinking is nitrous working fairly well for a 968 or S2.

but on a turbo, things could get really interesting.

Dougs951S

A nitrous shot provides ~ the same hp gain throughout the rpm range, meaning that yes, when it is engaged at low rpm it provides much more torque than it does hp, with that torque trailing off as rpm rises while the power stays roughly the same. At 2000 rpm, a 60 shot of nitrous is providing ~160 ft-lbs, at 3k ~ 105, dropping to around 60 ft lbs at 5k , and ~50 ft-lbs at redline. That huge torque spike is what can break rods if nitrous is engaged at too low an rpm.

An E-85 fed k26 car making ~320 ft-lbs at the tire would make over 450 wheel torque if it sprayed a 100 shot at peak torque. That same car would also make close to 400 whp if it sprayed to redline and had the fuel and tune for it. It may also put a stock rod through the block at that level, a 50 shot would be a lot safer. You'll want to pull 3 degrees of timing per 50 hp shot from all areas under the curve where you will be spraying.

V2Rocket

for systems...

racerxrick

I've nitroused a turbo car before...insta-boost! (87' Buick Turbo T Limited)

It was a challenge to launch the car consistantly at the dragstrip brake boosting. I wound up putting a small shot of nitrous on the car. You would just barely pull the car up on the torque convertor and then launch on the button. Instant 20psi. The car went from 12.20's to 11.70's and was very easy to launch.

The again I've had 12.90 cars (naturally aspirated) that dropped to 11.60's with a shot of nitrous too!

86 951 Driver

Did you run a wet kit? What did you do about tuning?

racerxrick

wet...you can control lean conditions to a great extent by jetting the fuel side solenoid correctly. No additional tuning was really needed. On larger shots of nitrous (I've had two stage systems in the past) I would run colder plugs and less timing.

BoostedBoxster

Hi, Im new here however I had to ring in, our shop has been putting together nitrous systems for years about a year ago we put together a small wet shot EFI nitrous system for testing on the owners 996 worked great started at 25hp now it's up to 125hp going like a bat of hell, so I ended up with a very nice 98 boxster high mile 2.5 5sp car I love it but needed a bit more power here and there so we put a system on it the boxster is at 60 hp has had 30 bottles through it not a issue, the owner has over 100 bottles through his 996 not a issue way we see it with any non turbo Porsche there running 11.1 to 12.51 C/R! So a supercharger or turbo will go boom a lot faster than nitrous will, nitrous loves high C/R with the added heat of turbos or a supercharger nitrous is the other way around its ice cold going into the motor tends to buffer pinging, I'm running 93 pump gas no pinging on the nitrous at all and keep in mind 60hp in nitrous is 80lbs of TQ so I can tell you first hand it wakes up my boxster dollar for dollar there is no better bolt on its king! Hell of a lot of fun!

BoostedBoxster

BTW there is zero tuning the jet is after the MAF before the TB the nitrous system has the ratio of fuel and nitrous PRE jetted so it's air fuel ratio is spot on the MAF never knows it happen and because WOT is the only time the nitrous is used the ecu is in closed loop the o2 see the 14. Air fuel the ecu wants all is good!