smc alky vs propain

[straycat990]

which system is the more user friendly? Cost effective? what is a realistic amount of boost that can be run with either system? Are there any changes that needs to be made to the fuel system to handle the added alky or propane? I am planning to add one of these systems to my car as soon as I get the new engine finished.

David Morgan
87 turbo t (completely stock)

new engine -- champion heads cnc series, atr 3 ss dp w/ext gate, 42.5 lb injectors, esp front mount, precision 6 disk l/u 3000 stall, john craig ta-61 and the list goes on and on and on

 

[JayC]

I can give you a view from the propane side anyway.

Installation is an hour or two with common hand tools. Biggest PITA is drilling a hole in the trunk to get the line out.

The electronics are prewired plug and play. All you have to do is plug them in and connect a hot and a ground.

The system is pretty easy to tune and compatible with a wideband O2 although stoich is slightly different with propane versus gasoline.

All the testers are running 24 PSI on pump gas with really no tuning changes other than turned the boost up gradually and playing with propane amounts. I believe more boost is possible however 24 PSI seemed to be the physical limits that the testers could get their cars to produce.

As far as alcohol, the SMC kit is pretty nice. I sold (Well, OGS sold it for the last few years) an alcohol kit since around 1994 so I have a lot of experience with alcohol as well. It's very hard to compare the two because even though the end results are the same (more boost), how they get there is very different. And remember, more boost doesnt equal more horsepower always

Hopefully I will be able to get one of the test cars on a dyno this month and see the different the propane makes. I expect the gains to be very substantial.

 

[blackbuick87]

Propane is probably more user friendly since it does not bog the engine unless you REALLY try to cram too much of it in the engine. Alcohol on the other hand floods the engine if you bring it on too soon, or too much.
Both do a great job of cleaning the engine, and keeping the combustion chamber free of deposits.

Installation time is about the same also. With propane you do not have to mix lube, a tank lasts a LOT longer, and you dont have to mess with alky/water mixtures. You do have to fork over a good sized portion of your trunk for the tank.

 

[straycat990]

well I must say propane is sounding like the better way to go and 24 lbs of boost is alot on the street Now my next question would be just how many runs can be expected out of a bottle of propane? Just looking for a general idea as to what can be expected.

Jay I am curious here .. any plans for add ons like NOS has .. electric valves to open and close the tank , remote pressure gauges(for in the car viewing),...bottle heaters. The other thing I am concerned about is how consistant will the propane injection be? I guess what I am getting at is what pressure is it being injected into the engine vs the pressure of a full tank of propane. Also .. has any of the test cars tried it with racing fuel yet ? Also what type of computer systems are the test cars running .. stock ecms with a chip or the felpro's fast or accells dfi?

ps Jay do you still burn chips?

 

[JayC]

You could use NOS's remote bottle opener without any problem. Might take a little adapting but it can be done. We could also develop our own easily but until there is more interest in this kit, we wont be producing many addons. It's just not feasible to do the work for 3 or 4 guys to buy them.

We already have pressure gauges thanks to some sleuth work by Brian Green.

We have bottle heaters in stock

The testers both went 4-5 months without refilling their tanks. Kenny said in another thread that he had about 80 passes and a bunch of screwing around on the street on his tank. Don't take this as the gospel though, I'm quoting from memory. It cost him $7.00 to refill his tank, BTW.

As far as consistency, remember that we use a regulator on the propane outlet. As long as you have enough bottle pressure, it's going to be consistent. In the spring/summertime, it's no problem, in the winter a bottle heater takes care of pressure issues.

No one is using race fuel because the whole point of this was to see how much boost we could run with pump gas. Given propane's burn charecteristics, I see no reason you couldn't use it with race gas but like alcohol, I question the purpose of doing it.

All the test cars are basic, low 12 cars. They all use the stock ECM.

Yes I still do chips.

 

[straycat990]

Thanks Jay I am heavily leaning towards your propane kit. It truly sounds like the way to go. The idea of the racing fuel was to be able to run more boost if that is possible. It was just a thought any way. I will definitely be talking with you about a chip. I just have to iron out what I am going to do for a camshaft. I am trying to and want to run a mech roller cam. Just there is some issues about the lifters and if the oil holes will be exposed. any input you have on this would be great.

thanks again,
David

 

[JayC]

I use hydraulic rollers in about 90% of the engines I build.

 

[joereitman]

Originally posted by JayC

We already have pressure gauges thanks to some sleuth work by Brian Green.

We have bottle heaters in stock

As long as you have enough bottle pressure, it's going to be consistent. In the spring/summertime, it's no problem, in the winter a bottle heater takes care of pressure issues.

Jay- I am interested in the in car pressure gauge- can you please provide more detail? Thanks.

Regarding bottle heater, I will be injecting pre-turbo, like a lot of the diesel guys do, so all I need is 20 psi. Thus, no need for bottle heater unless it gets well below freezing. Have you considered injecting at around 40-50 psi in your post turbo system instead of the higher pressures some folks are using? That would allow system use without bottle heater. Of course, you would then need a larger jet I presume.

After the much publicized nitrous explosion in the Maxima a while back, bottle heaters concern me. However, maybe your bottle heater has an automatic safety shut-off once a certain temp is exceeded?

Thanks,

Joe

 

[JayC]

Originally posted by joereitman
Jay- I am interested in the in car pressure gauge- can you please provide more detail? Thanks.

Replace one of the gauge on the regulator with the sending unit, wire it up in the cockpit, youre done.

Regarding bottle heater, I will be injecting pre-turbo, like a lot of the diesel guys do, so all I need is 20 psi. Thus, no need for bottle heater unless it gets well below freezing. Have you considered injecting at around 40-50 psi in your post turbo system instead of the higher pressures some folks are using? That would allow system use without bottle heater. Of course, you would then need a larger jet I presume.

I have no desire to inject pre-turbo and in our testing, you need 70-80ish PSI minimum to support the gains we are seeing. In your application things may work differently.

After the much publicized nitrous explosion in the Maxima a while back, bottle heaters concern me. However, maybe your bottle heater has an automatic safety shut-off once a certain temp is exceeded?

This cant happen with our bottle heater if it is used according to instructions. That particular heater in question used a pressure sending unit to control the heater power, the owner closed the bottle but left the heater on.. no pressure, the heater just kept running.

 

[joereitman]

Thanks Jay- is there any particular reason some of the diesel systems are pre turbo, but the gas systems are not? I can't think of any real downsides to pre turbo, can you?

Thanks,

Joe

 

[ACLR8R]

Just thought I would put a plug in for the SMC kit. I have no experience with propane so I dont know which is better. I got a dual nozzle kit a couple weeks ago and it rules! I went from about 14lbs on pump gas (91 octane) to 19/20 lbs on alky, with the pump speed on about 3 1/2 out of 10. You can run through the alky fairly quick though, but it still lasts me about 2 weeks a bottle. It was worth every penny!! Best of luck

 

[fast eddie]

no heater needed for alcohol,no bulky tank,no hard #s here yet because of the weather in michigan right now butt, the SMC kit was easy to install with great resaults as of now just crusing around with plunty of wide open blasts , no kr on pump gas 20#boost, pump set at #7,with turn on at 12psi love the smell of alcohol in the morning!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Vader 87]

Any track times with propane?

 

[JayC]

Yea, theyre somewhere in another thread. I'll have to look around for them. Its been a while since they were posted. Maybe Kenny will chime in and repost them and save me the trouble of digging for them.

 

[JayC]

Actually, look here.