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Author Topic:   alcohol or race gas
jd97brian
Dirt Full Roller

Total posts: 46
posted December 02, 2004 06:16 PM  
I was looking for opinions on whether to use alcohol or race gas in a modified? I use alcohol now but would there be any advantages to gas?

bauman
Dirt Roller

Total posts: 11
posted December 02, 2004 08:19 PM  
The biggest advantage to use race fuel is for rear weight. As you know you will burn twice as much alcohol as gas so deeper into the race you will have less rear weight after burning off your tank. Plus I think that it is a little easier to maitain than an alcohol system.

donslink1
Dirt Freak

Total posts: 318
posted December 02, 2004 08:51 PM  
Ya but gas runs hotter, So you need a bigger radiator, Gas makes less power
and gas is three to four times more money per gal.
For ever I worked with alky, Just last year I worked with a guy that ran gas and didnt like it too much.

mdsteacher
Dirt Maniac

Total posts: 145
posted December 02, 2004 09:42 PM  
We've run both gas and alky and prefer 110 octane gas. Gas is easier on the engine and will extend the life of parts. Alcohol corrodes fuel pumps, carbs, etc. The extra expense up front for race fuel pays off with longevity and ease of use. BTW, we have never had any over-heating problems on gas. We don't even use a fan shroud. The key is keeping the fan blade close to the radiator; use a large aluminum bladed fan, and remove the side skirts on the front nose to allow air to flow.

zeroracing
Dirt Forum Champ
Total posts: 1875
posted December 02, 2004 10:01 PM  
I run gas, and wont go to alky. The biggest advantage is like bauman said rear % the car wll stay more consistant. What does this mean to the average racer? Start races lighter and keep the car handling all the way through the race.
Gas does not draw as much moisture as alky.
Gas does not run hot if you put keep the rad clean and full. I run a cheap rad from speedway, aluminum fan(four blade is better though), aluminum water pump. and 90% of the time i have about 40% of the radiator blocked off.
the power difference depends on engines, i know late model motors that only have 5hp difference. also side note-MOST MODS ARE OVERPOWERED!!!!!!!!!!!!!!!!!!!!!
i also dont use a fan shroud.
the cost at our track is about the same, i mean per gal gas is 2x as much but you burn so much more so...
last but not least gas is safer to handle.

sleepy 1h
Dirt Full Roller

Total posts: 63
posted December 03, 2004 02:37 AM  
I use alcohol,and I'll stay with it for these reasons. most people scale there car with about 15 to 18 gal fuel in it, I have a 32 gal fuel cell and for a heat race I have about 20to 22 gal in it and only burn about 5 or 6 gal of fuel,and for the feature I put about 28 to 30 gal fuel in it by the time the 20 lap feature is over I'm right back to the scaled weight.So as the race progesses I lose a little of the rear % ok but I started with a lot more then I even scaled with.2. More horsepower, higher compression means more power.with gas you are limited to the compression you can run if you go to high that means detonation,and there goes pistons,bearings and some times crank and rods.And they do make lub you can run so it isn't as hard on your parts. And to top it all off, alcohol is not a petroleum product,with means I get it alot cheaper then gas even if I do burn alittle more. since this oil price thing going on what do you think its going to do with the higher octane fuels,especially since theres not as high of a demand for it.Just my thoughts. sleepy

sleepy 1h
Dirt Full Roller

Total posts: 63
posted December 03, 2004 02:42 AM  
zeroracing, I like a little moisture its call liquid horsepower,what is water Hydrogen and Oxygen but with are fuels, and keeping an engine cool is easy if you know what your doing,even if the front is blocked off. sleepy

[This message has been edited by sleepy 1h (edited December 03, 2004).]

FASTLAP
Dirt Maniac

Total posts: 171
posted December 03, 2004 04:23 AM  
Gas carbs are cheaper, too. I've run alky and unless you keep on top of it, chances are it's going mess something up thru corrosion.
But true, most lates are on alky....

Dman
Dirt Freak

Total posts: 270
posted December 03, 2004 08:12 AM  
Yo Zero!
Gas is not safer to handle.Gas is more volatile and unstable than methanol.That is why more compression is required with Methanol than gas to make the same power.Methanol has a higher octane rating than gas which means it is harder to ignite thus less chance of detonation or(pinging).That is why Methanol runs cooler.
You won't foul a plug from Methanol unless it is from worn rings or valve guides.You can get away with running rich with methanol but will foul a plug if rich with gas. Racing fuel does smell better out the exhaust than Methanol and you don't need near as complicated a fuel system for gas.
But I think I will stay with Methanol.If you run Methanol or Alky lube you won't have the maintenance problems or deterioration you talk about.Also if you run Methanol you don't have to be as worried about a little mud in your radiator.There are alot of trade offs but our engines have lasted alot longer on metanol than our gas ones did because of less problems with heat and detonation.I'm done now.
Dman

zeroracing
Dirt Forum Champ
Total posts: 1875
posted December 03, 2004 12:08 PM  
i run about 150 unless i have most all the rad blocked off. so the mud in the rad is not a problem either. but most people need to keep it clean.
I can get about 80+ races before a rebuild is needed.
also a side not a good friend lost a race because he ran out of alky one night. they ran 96 laps by the time they got all the caution laps and partial laps in. he had an almost full cell before he started. it cost him the race, and later in the year it turned out it could have been the difference in him finishing first and second in the region, the guys were almost tied. 40,000 dollar mistake. he sure wishes he ran gas that night.

[This message has been edited by zeroracing (edited December 03, 2004).]

Dman
Dirt Freak

Total posts: 270
posted December 03, 2004 02:09 PM  
zeroracing, Ahhh yes, there is always someone who wants to debate.I was just sharing my experience.
It wasn't meant to insult. The only time we've ever run that cold on gas or methanol was at Las Vegas last year.It was 40 degrees with a wind blowing. Please give me your secret.Besides us westerners (as I have been called lately)like to be environmentally friendly by running alternative fuels.You know,Save the whales dude! LOL
Dman

zeroracing
Dirt Forum Champ
Total posts: 1875
posted December 03, 2004 02:34 PM  
To be honest we can not figure out why this motor runs so cool. but i run protopline heads super vic intake, 010 block, racing aluminum water pump not super pricy, 1:1 pulleys, speedway tru cool radiator, large alumnum fan up close to the rad.
this same motor overheated under caution when we ran it on a 2barrell and ran 30% reduction pulleys.
also no restrictors.
the main drop in temp was when we went with 1:1 pulleys. also a friend ran a mod on gas and had overheating problems, but then went to 1:1 pulleys and it fixed it.
alot of guys are goign to gas, usmts guys and local guys, also many late models run gas.
every two or three races i back flow the radiator(back to front with a low pressure garden hose).
also side note-i could not agree more about plastic lines its an accident waiting to happen.

mod70
unregistered Total posts: 1875
posted December 03, 2004 06:28 PM           send a private message to zeroracing   Edit/Delete Message   Reply w/QuoteBBBBBB
Hey Dman, just a note, QUIT SNIFFING YOUR EXHAUST! (of course this may explain you westerners)LOL. You made the note that racing gas smells better, but if I remember isn't racing gas leaded? If so that is what you are smelling. Burning lead has a sweet smell, and is also the quickest way to get it into your blood. So much for saving the whales. (you murderer zero)

[This message has been edited by mod70 (edited December 03, 2004).]

zeroracing
Dirt Forum Champ
Total posts: 1875
posted December 03, 2004 06:50 PM  
hey mod 70 most the stuff we run around here is unleaded. you can get leaded i had a guy give me a card a few years back he had leaded fuel.
but i dont think that most racing fuel has lead in it. DONT HOLD ME TO THAT! but i dont think so.
i hate the smell of alky the only thing worse is alky+nitro.
by the way mod70 you have been smelling that at the track too. did you know that?? a few cars look for a littel advantage at cms.

mod70
unregistered Total posts: 1875
posted December 03, 2004 08:54 PM           send a private message to zeroracing   Edit/Delete Message   Reply w/QuoteBBBBBB
Yeah, that wouldn't suprise me. Unfortunatly, at CMS I've usually been stuck with having to smell exhuast. The reason for lead in gas is because it acts like a lubericant. I use top lube in my alky like sleepy was talking about.

I run alky just because of the HP gain. I know that it might not be much, and that it's hard to get the power to the ground in a mod, but there are guys out there that have the bucks to out power me so I will take horses where I can find them. I can adjust my driving to make up for the loss of rear %, but when it's on the floor I can't get any more than that.

uforacing51
Dirt Forum Champ
Total posts: 570
posted December 14, 2004 03:27 PM  
Try following a car that is running WAY rich and running alky. My eyes were watering so bad I couldn't see to pass him. I finally shot past him when he slowed for an accident, it was blind luck (literally) that I didn't get in the accident and managed to pass him. I prefer alky though as although we run alot more, it is cheaper and, it keeps the car cool. On hot nights, it works better than some cars.

gould
Dirt Forum Champ
Total posts: 730
posted December 14, 2004 04:03 PM  
can someone clear a rumor up for me...if i remember hearing right running alcohol will increase your torque and running race fuel will increase horsepower. this was a comparison of one over the other. i understand the other replys about the weight issues and burning more alcohol. with race fuel you could also run a smaller cell and put the weight where you want it.

------------------
www.geocities.com/gouldracing11

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted December 14, 2004 04:07 PM  
It is possible get race gas that is unleaded but I would venture to say that what most of us run is still the good 'ole leaded stuff. At least around here anyway. In fact i would have to double check again but i think it is well above the lead content of the old leaded pump gas.

If you are running alky without a top lube of some sort you are asking for problems. The lube protects all your fuel system from the drying and corrosive properties of the alky. You can buy scented oil if you want to burn it as well...makes your car smell like a cherry, or watermelon, or root beer..... etc.

[This message has been edited by dirtbuster (edited December 14, 2004).]

Todchester
Dirt Roller

Total posts: 23
posted December 14, 2004 05:36 PM  
quote:
Originally posted by gould:
can someone clear a rumor up for me...if i remember hearing right running alcohol will increase your torque and running race fuel will increase horsepower. this was a comparison of one over the other. i understand the other replys about the weight issues and burning more alcohol. with race fuel you could also run a smaller cell and put the weight where you want it.



Yes alcohol produces more torque and gas more hp. But the hp. gain with gas is about 8-15 hp. The torque gain with alcohol is about 25-35 lb/ft.
This is the reason almost all USMTS cars switched from gas to alcohol in the last year. With the new rear suspension setups they can hook up the extra torque of alcohol.The cars still running gas got killed off the turns. But they all say the valve gide, valve stem, piston ring ware is greater than with gas.

gould
Dirt Forum Champ
Total posts: 730
posted December 14, 2004 05:38 PM  
won't the upper cylinder lube help with wear? forgive me im new!

brownstone
Dirt Freak

Total posts: 284
posted December 15, 2004 08:00 AM  
First off if you cannot get the same or more hp running gas, then look at making engine or engine builder change, Nascar does not seem to have any trouble making power on gas and neither do we. You might get a slight torque advantage running alky, but that will vary depending on your engine combonation.

Gas is smoother of the corner and also, IF their is a reduction in torque compared to alky that may help your cause on the IMCA tire or the Hoosier tire getting it to hook up off the corner.

Depending on the price and quality of the gas you run you can exceed the alky hp and torque without a problem I have seen it on the dyno with my own eyes.

I know that the carb has required a ton less maintaining since switching to gas. With some research and some plumbing you can eliminate any cooling issues running gas.

[This message has been edited by brownstone (edited December 15, 2004).]

donslink1
Dirt Freak

Total posts: 318
posted December 15, 2004 03:10 PM  
Well first of all nascar has $80,000 in there engines you can get away with running a lot of compression and high rpm and a lot of power and keep it cool when you can run drysump and a radiator that is 4 inches thick.
the biggest thing with alky is the cooling.
you can run more and keep it cool in the summer.and it gives more power

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted December 15, 2004 03:25 PM  
Actually nascar cup cars i beleive are limited to only 12:1 compression. busch cars a measly 9:1. Dirt late models W/ 15:1 can keep gas cool. Its all about getting the right cooling system together and maintaining it.

Alky will help midrange torque but in most cases gas and alky will make the same peak HP. The midrange torque boost is what helps off the corner, but it can also kill some cars that cant hook up the power they have.

[This message has been edited by dirtbuster (edited December 15, 2004).]

BrianW
Dirt Freak

Total posts: 385
posted December 15, 2004 03:39 PM  
quote:
Originally posted by donslink1:
Well first of all nascar has $80,000 in there engines you can get away with running a lot of compression and high rpm and a lot of power and keep it cool when you can run drysump and a radiator that is 4 inches thick.

Nascar (assuming Nextel cup here) does not run that much compression - plus they run long races where pitting is required - they have a fuel quantity limit and running methanol would kill their miles per tank number... Most short track racers don't think about pit strategy nor fuel conservation since the races are so short and can be run on much less than 1 tank...


nolimit92
Dirt Forum Racer

Total posts: 97
posted December 15, 2004 05:12 PM  
There is definately advantages and disadvantaged of both. Metanol is not alot cheaper then racing fuel. We burn 2 times as much then racing gas. Yes it is still cheaper but not alot.

I can tell you for a fact Methanol does make more HP and More torque. Dyno sheets prove that. Most us Modified drivers try to run as much compression as we can while still keep the engine durable. Methanol burns slower so inturn burns almost the entire time the piston is on the downward power stroke. I have seen dyno sheets on a 383 with 13-1 compression, it made 534 Hp and 405 pnds of trq on racing gas. Same engine on Methanol made 556 HP and 421 Trq. At least that is close to the numbers I remember.

Mike

wfoondirt
Dirt Forum Champ
Total posts: 505
posted December 17, 2004 01:10 PM  
You can't take an alky motor and put a gas carb on it and expect to make the same power. Cam profiles are different for gas and alky motors. We made the same hp and within 5% of the same torque switching from alky to gas. Also with the quality of race gas today you can run upwards of 16,17-1 compression without worrying about detonation. The higher compression narrows the gap that used to exist between gas and alky.

The slight loss of torque was worth not having the problems associated with alky. Alky is harder to tune, most people just jet them pig rich and end up washing the cylinder walls and also killing the small gains they saw on they dyno. Cooling is really not an issue with modern race gas. We never ran over 200* in our l/m this year with the nose completly closed. Also you have a much simpler/cheaper fuel system with gas, ie no bypass and belt drive pump. The biggest reason is the fuel burnoff, why carry the extra 100lbs of fuel at the start and deal with the changes in the chassis as it burns off. I ran alky in a mod for over 10 years and now after switching to gas I won't go back.

donslink1
Dirt Freak

Total posts: 318
posted December 17, 2004 04:12 PM  
You probly did run 200 in your l/m because you have ducting in front of the radiator and behind. With jets your area for making the peek horse power with alky is way bigger than gas. If the temp. out side changes a little bit you have more of a chance of loosing h/p with gas than alky when it comes to jets. and if I was running 17-1 compresion I wouldnt be worried about running hot or what ever I would worry about head gaskets.

brownstone
Dirt Freak

Total posts: 284
posted December 18, 2004 07:29 AM  
wfo, said it right, by the way the new cometic head gaskets while not cheap will hold a lot of compression.
Gas will work fine and the tuning is not a big issue either. The wear and corrosion that alky has on the pump and carb alone is worth switching to gas.

Some of the gas available now although really pricey will show improved numbers over alky but we are talking in $5.00 a gal price also.


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