propane......7-10lbs boost = ?? horsepower

[1TONY1]

pro-pain, 7-10lbs boost = ?? hp..Viper help

Hi guys, I am looking at doing a propane/nitrous (maybe propain) kit on a 1996 Viper. It is supercharged with an Autorotor nonintercooled screw blower (like Kennebell). I will need to come up with a starting nitrous jet size. I understand that with the Propain kit you can increase boost about 7-10 psi and add a little timing. Does anyone know how much hp 7-10 lbs of boost equals on a GN ? Please specify flywheel or rwhp increase. As in ....if you are using a Propain kit, what size jet are you using to raise boost "how much" and have you dynoed to see the hp increase in that boost ? That is one way I have come up with to ball park a n02 jet size......comparing hp of 7-10psi and relating that to a hp/n02 jet. Another more technical way would be to somehow use a formula similar to a nitrous lbs/fuel lbs ratio like is used to do nitrous tuning.

 

[BLACK6PACK]

It varies too much from car to car even on GNs. A stock GN adding 5 lbs of boost will not get as much return as one with hogged out heads and a monster turbo.

A general rule of thumb approximation on GNs is 10-15 hp per 1 lb of boost. So, going from 15 lbs to 25 lbs of boost will get you about 100-150 hp.

 

[HurstGN]

Look to a Mopar guy

You may want to direct this question to Matt at Dynamic Racing. He's more than experienced with the use of propane, and he does deal with Mopars. Perhaps he's done this on a Viper and can save you some headaches.
Dan

 

[motorhead]

~10 flywheel HP per 1psi of boost... assuming every idea variable.

I have gone up ~3-4psi with early propane tests. Using old 94 gas, a race chip with too much timing, and the #86 jet in the Pro-Pain kit.

Soon, I'll have a lower timing chip (equiv. to 100 octane), fresh gas, and a #93 jet in place... I hope to gain another 5psi.

HTH,

 

[S10xGN]

What's the normal [propane] boost increase for street use? I'm seeing 7# - 8# here on the board, so *IF* I can get that, I'll be pushing 23# - 24# on pump gas and a 19/18 Testa chip. Is that expecting too much from my bottom end?

 

[Turbo__Tim]

Should be ok. How much boost are you running on pump gas now? 15 psi? Should be lower than most with the ported heads...

One rule of thumb is the stock bottom end is safe to around 600 hp. That equates to a 10.68 et @ 128.

If you are running a 12.2 @ 112 mph, (400 hp) and strap on another 90 hp, this would give a possibe 11.4 et @ 120.

Here is the link I took the et, and hp figures from....

www.gnttype.org/techarea/misc/lubrant.html

 

[1TONY1]

Hey...quit hijacking my thread I have been having hard drive problems so just now gettig to check the replies. I ordered a pro-pain kit today.
Here is part of an e-mail I sent to someone that is propane wise. I would still like to get feedback from some that are running pro-pain. My engine will appreciate your thoughts.

I just want your ideas on where to start with propane
jetting and regulated pressure. We are going to start with a pair of 28 or 32 (75-90 hp) nos jets in a pair of annular discharge fogger nozzles. I will be using nos jets on the other side of the fogger for the propane. A good starting point would be to know what pressure and jet would make 100 hp, then I would have to come up with 2 nos jets that equal the flow of your one jet. I would rather use a 80 - 100 psi regulated pressure instead of
higher....seems like it would give more room in cold weather/lower pressure.

60 pounds per hour of gasoline = 100 horsepower. Do your know what a similar measurement of propane would be? Any guidelines for weight/hp on propane ? We usually set our nitrous stuff up by flowing it using the weights.

 

[Turbo__Tim]

100 HP isn't going to happen. Not with propane alone. 75 hp gain at the engine is more like it.

You will reach a point where the propane vapor displaces too much oxygen in the intake charge to be effective. You will flood out.

If this were a liquid propane and nitrous kit, 100 hp would be possible.

Basically I'm bumping this thread up so Propain users can tell you what size jet they are using. from threads posted here the smallest one is the most likely chioce.

 

[motorhead]

Hmm... I am currently using the largest (#93) jet in the kit.

And I have yet to see any reoccuring knock. Granted, I am down ~3psi from my early tests @ 20psi & using the #86 jet... I have since turned down the boost, and put the cat back on, and bumped up the jet size. I am currently running a JC110 race chip... and waiting on a JC100ish propane VT chip. I am playing it safe until my new chip arrives in the mail.

The basic settings @ the C/C are:
Injection point: ~7psi
Duty Cycle: Near 100%
Over Boost: As delivered (haven't taken the time to figure this one out yet)

Tank pressure regulated @ 150psi.

The car pulls like a bat out of hell...

HTH,

 

[HurstGN]

Over Boost: As delivered (haven't taken the time to figure this one out yet)

Michael,
Overboost is simply a safety device. Moving from a car used to running 15-17 lbs of boost and watching for say 1-2 degrees of knock...to...22-24 lbs of boost with no knock, it's easy to get carried away with the right foot. This is where the overboost light comes into play. It's set to 20 lbs as a default. Lets say you set a limit of 25 lbs of boost. You don't want to go over 25 lbs even if things are running fine, just for safety sake. OK, crank up the overboost setting to 25 lbs. Now the overboost light will come on at 25 lbs to warn you you've hit your limit you don't want to exceed. It does NOT affect any of the functions otherwise. It only lets you know you've reached a desired setpoint. The overboost light will also work even if the Pro-Pain Control Center is turned off. Just figured it was safer to do it that way in case the system was accidently turned off.
Simply put, the overboost is an idiot light that costs far less than the other kind of idiot light you can see if you overboost the car....the one in the rearview mirror cause you've been an idiot to pass a cop on the side of the road at 25 lbs of boost.
Dan

 

[motorhead]

Originally posted by HurstGN
Simply put, the overboost is an idiot light that costs far less than the other kind of idiot light you can see if you overboost the car....the one in the rearview mirror cause you've been an idiot to pass a cop on the side of the road at 25 lbs of boost.
Dan

LOL!

Dan, I knew its purpose, I just hadn't bothered to adjust it... playing with the go pedal is waaaaaaaay more fun.

I hope to have some "numbers" soon to help quantify the gains.

 

[1TONY1]

Originally posted by Turbo__Tim
100 HP isn't going to happen. Not with propane alone. 75 hp gain at the engine is more like it.

You will reach a point where the propane vapor displaces too much oxygen in the intake charge to be effective. You will flood out.

If this were a liquid propane and nitrous kit, 100 hp would be possible.

Basically I'm bumping this thread up so Propain users can tell you what size jet they are using. from threads posted here the smallest one is the most likely chioce.

So you don't think propane (vapor) will support 10-12 psi of boost before you reach that point ? Also it may be possible to have more n02/propane than boost/propane before it displaces the oxygen. This guy claims 95 rwhp gain by adding his propain to a nitrous kit. (75 rwhp with dry nos then 95 more rwhp with propane and more n02) http://www.btrviper.com/nitrous.html it is a nonregulated. He does back his numbers up with e.t. This is r&d stuff so just looking for any thoughts. tnx, Tony

 

[Turbo__Tim]

Thanks Tony! It's good when people take the time to research..

Ok using the link, I selected 'performance results' at the top of the page. That took me to here...

http://www.btrviper.com/results.html

Then I selected this article....

BTR's new 750 Super Snake Performance Package
with propane and without propane.
10/23/01 dyno run

Then this chart...


http://www.btrviper.com/750SS-Propane_Dyno.jpg

And this one...


http://www.btrviper.com/750SS_Dyno.jpg


(Seleting 'without propane' showed a chart with a 631 HP result. 'With propane' showed a chart indicating 673 HP - a 42 HP improvement.)

They are using race gas of course...

Is this what you were refering to? If not, how about a direct link to the hmtl document in question, or just copy and paste it here?

There are some interesting kits there. I didn't see a liquid propane mentioned, tho I did see them specify a 'dry' nitrous kit.

 

[1TONY1]

I was just using what he was rating the dry nos kit at (75 hp) compared to what he was rating the dry kit plus n02 at (170 hp) I think. But , you are looking at dynos.....we KNOW no one would say their stuff made more hp than it really does. I will go look at the dynos and try to find a few dynos on the Viper board with and without his propane kit. You are correct in looking at the dynos....more investigating to come. tnx

 

[Turbo__Tim]

Hehe, lets go crazy! I already have a propane tank in the trunk, so why not add a nitrous tank, and a 5 gallon methanol alchy fuel cell to keep 'em company!

No - wait! How about a race gas cell as well? Why not? Hell got to fill up all the room back there, proilly have room for a couple JATOs as well.

The next time a little old blue haired ladie hits my car, I will be seeing her in hell!

KaaaaaBooooom!

MUHAAAAHAAAAHAAA!