Found out how Old NA's went fast, lookie here
05-29-02, 12:48 AM
#1
Thats not an FC...
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Found out how Old NA's went fast, lookie here
Interesting question! As a general rule for all
engines, anymore octane than the engine needs is a
waste of power. To simplfy, the higher the octane, the
"slower" the burn rate of the fuel. So if your engine
ideally needs 30* of timing and you add higher octane
fuel, you will need to advance the timing to get it to
burn completely. The earlier before TDC you light off
the fuel the longer the rotor or piston has to fight
through the expanding fuel before reaching TDC and
head "down" on the power stroke. During the days of
the IMSA GTU racing, the p port motors originally
smoked badly in the fastest of the rotary cars. Why?
The fast guys found that by adding more oil that was
necessary to the gas lowered the octane!! Low octane,
less ign. timing, less power lost from the rotor
pushing past the expanding gases. If you p port is set
up correctly, it will run just fine on cheap unleaded.
In hot conditions , premium can help prevent vapor
lock. Also if comparing, some race gases contain
additives that enhance power. Depending on how "good"
the gas you get in your area is, the premium may be
better refined, less contaminated so my produce more
power. For the turbo cars, proper tuning goes a long
way. Ralph Friend of Xcessive motorsports makes over
620rwhp on 100 av gas. A daily driver also. Rob (Golden, pineapple racing)
engines, anymore octane than the engine needs is a
waste of power. To simplfy, the higher the octane, the
"slower" the burn rate of the fuel. So if your engine
ideally needs 30* of timing and you add higher octane
fuel, you will need to advance the timing to get it to
burn completely. The earlier before TDC you light off
the fuel the longer the rotor or piston has to fight
through the expanding fuel before reaching TDC and
head "down" on the power stroke. During the days of
the IMSA GTU racing, the p port motors originally
smoked badly in the fastest of the rotary cars. Why?
The fast guys found that by adding more oil that was
necessary to the gas lowered the octane!! Low octane,
less ign. timing, less power lost from the rotor
pushing past the expanding gases. If you p port is set
up correctly, it will run just fine on cheap unleaded.
In hot conditions , premium can help prevent vapor
lock. Also if comparing, some race gases contain
additives that enhance power. Depending on how "good"
the gas you get in your area is, the premium may be
better refined, less contaminated so my produce more
power. For the turbo cars, proper tuning goes a long
way. Ralph Friend of Xcessive motorsports makes over
620rwhp on 100 av gas. A daily driver also. Rob (Golden, pineapple racing)
Rob said that these were PP cars, so im not sure if it would work all that well on stock port NA's.
but, i AM running premix in addition to the stock OMP, so maybe im on my way to making my own "RACE GAS"
chris
05-29-02, 04:50 PM
#3
I came, I saw, I boosted.
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I SOOOO beg to differ!
I guarantee that my car, without the street port, and minus the A/C, P/S, and stereo.. (so, well over 100lbs weight reduction) would easily be still running 14's....(high though)
I doubt my steet port is good for a over a full second in the 1/4...who knows...
Oops.. I just saw the "S4" condition... well, it still can be done.
Good engine with excellent compression
Intake ported, with a K/N, and TB mod.
6 port sleeves smoothed, cut 1/2, and locked into place.
No emmisions of any kind of course.
Header, full free flowing exhaust (dual or single).
Lightweight flywheel, and some 225's in back...
No PS, AC, maybe strip the sound deadening.
Definately an S-AFC, and bump timing up a few degrees.
For an S4, That should do 14's with pretty full interior.. if not- gut it, and it will.
The thing is, most s4's have a lot lower compression than when new.... all the ones I've driven have, and damn they're slow...
And oh... the whole octane thing is correct... however, it won't make your engine LOOSE power running at higher octane, EXCEPT at VERY high RPM's, where the combustion time is so small, that the slower combustion of the higher octane gas doesn't allow for full combustion!
At lower rpm's (probably under 8000) the higher octane has the same power potential, since it combusts to the same gas (air gas) volume.... pushing the rotor.. .it just takes longer to reach it's expansion maximum....
People that run 94 octane all the time in their FC's (NA, or TII under 15 psi) are nuts, and wasting money though... sometimes the higher octane stuff does contain a higher concentration of cleaners though, but it all depends....
I guarantee that my car, without the street port, and minus the A/C, P/S, and stereo.. (so, well over 100lbs weight reduction) would easily be still running 14's....(high though)
I doubt my steet port is good for a over a full second in the 1/4...who knows...
Oops.. I just saw the "S4" condition... well, it still can be done.
Good engine with excellent compression
Intake ported, with a K/N, and TB mod.
6 port sleeves smoothed, cut 1/2, and locked into place.
No emmisions of any kind of course.
Header, full free flowing exhaust (dual or single).
Lightweight flywheel, and some 225's in back...
No PS, AC, maybe strip the sound deadening.
Definately an S-AFC, and bump timing up a few degrees.
For an S4, That should do 14's with pretty full interior.. if not- gut it, and it will.
The thing is, most s4's have a lot lower compression than when new.... all the ones I've driven have, and damn they're slow...
And oh... the whole octane thing is correct... however, it won't make your engine LOOSE power running at higher octane, EXCEPT at VERY high RPM's, where the combustion time is so small, that the slower combustion of the higher octane gas doesn't allow for full combustion!
At lower rpm's (probably under 8000) the higher octane has the same power potential, since it combusts to the same gas (air gas) volume.... pushing the rotor.. .it just takes longer to reach it's expansion maximum....
People that run 94 octane all the time in their FC's (NA, or TII under 15 psi) are nuts, and wasting money though... sometimes the higher octane stuff does contain a higher concentration of cleaners though, but it all depends....
05-29-02, 06:33 PM
#5
Thats not an FC...
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By Rob, you mean Rob Golden, at Pineapple Racing
[BOLD]Rob (Golden[/BOLD], pineapple racing)
pile on top of a good launch, good shifting, good compression; Pineapple sleeves and a mazdatrix header, and possibly match ported Upper and lower intake. you dont think i can break 14s w/ that set up?!
i think i should do it, just to prove you nay-sayers wrong. if someone doesnt buy my car first.
chris
05-29-02, 08:28 PM
#6
You can do anything with any kind of engine with minor mods you can get a good 40 hp out of an n/a with good exhaust! cold air intake no a/c better spark plugs and higher performance feul pump and better injectors and changing your pulleys to low weight pulley's and an electric fan! i am sure with those mods you could easily run high to mid 14's without porting!
05-29-02, 08:52 PM
#7
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Originally posted by jreynish
You can do anything with any kind of engine with minor mods you can get a good 40 hp out of an n/a with good exhaust! cold air intake no a/c better spark plugs and higher performance feul pump and better injectors and changing your pulleys to low weight pulley's and an electric fan! i am sure with those mods you could easily run high to mid 14's without porting!
You can do anything with any kind of engine with minor mods you can get a good 40 hp out of an n/a with good exhaust! cold air intake no a/c better spark plugs and higher performance feul pump and better injectors and changing your pulleys to low weight pulley's and an electric fan! i am sure with those mods you could easily run high to mid 14's without porting!
By better injectors do you mean larger? If so that combined with a "high performance fuel pump" will almost guarantee your car to run worse. Making your car run rich is a great way to get worse gas milage as well as worse performance.
40HP gain while retaining the factory AFM? Good luck. I'd like to see it.
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05-29-02, 09:35 PM
#8
QC Motorsports
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Dude why don't you watch some racing. The richer you run the more hp you get. At least thats what the indy guys say. I will believe them before I believe someone on a forum. Thats why they run lean, To get better gas mileage and the last lap run full rich. It makes more hp for higher speeds. Just what they tell me anyways.
Charles
Charles
05-30-02, 08:39 AM
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If running rich is the way to go then why do people get the S-AFC and lean there mixture out? To make more HP. What happens when someone installs larger TII injectors on their N/A? It runs worse because its running rich. What about a TII fuel pump on an N/A? Its a waste of time.
telus.net - Just run the 87 octane gas and you will be fine for an N/A engine.
telus.net - Just run the 87 octane gas and you will be fine for an N/A engine.
05-30-02, 09:39 AM
#13
Rotary Freak
Wow..lots of misconceptions on here..People like bambam and PPnos have dynoed thier car with S-AFC , timing exc...Thiers proof.
Lol...My car is juuuuust about a 14s car already with minor mods...89GXL 180 lbs weight reduction and bunch of cheap little stuff.
I beat this 3000GTSL with intake exaust running 15.3 Its a 94 224 stock hp. I beat him by 3 cars on his bad launch and 1.5 cars on his good launch. That night I new I ran a 14.9 or 15.1 at least. Engine stock rebuild 20,000 miles ago with perfect compression and some top end mods.
Lol...My car is juuuuust about a 14s car already with minor mods...89GXL 180 lbs weight reduction and bunch of cheap little stuff.
I beat this 3000GTSL with intake exaust running 15.3 Its a 94 224 stock hp. I beat him by 3 cars on his bad launch and 1.5 cars on his good launch. That night I new I ran a 14.9 or 15.1 at least. Engine stock rebuild 20,000 miles ago with perfect compression and some top end mods.
or protect your soft valve seats? 
05-30-02, 11:14 AM
#17
Administrator
no for my lawn mower .. ; P
i didn't mean that as a technical comment, it was merely a reference to the era of nasty leaded / low octane gases of the 70s and early 80s before all this fancy clean high octane stuff was avalble....
sheesh..
i didn't mean that as a technical comment, it was merely a reference to the era of nasty leaded / low octane gases of the 70s and early 80s before all this fancy clean high octane stuff was avalble....
sheesh..
05-30-02, 11:25 AM
#18
QC Motorsports
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Well guys it may cause the rotary to run bad but the crew cheif I talked to for this indy racer said the more lean they run the better gas mileage but lower hp, and the richer they ran the morehp and shity gas mileage. He said going from way lean most of the race to ful rich adds like 50-60mph for the last and fastest lap. If they aren't on a caution the last lap. Thats how the guy at the indy 500 won this year. he went ful lean and dumped as much fuel as he could into the engine with out flooding it. then the caution came out on a back turn and he coasted in for the win on .04 gallons on gas. He didn't make it to the winners circle thing. the car died on the victory lap. Thats what I was told.
Charles
Charles
05-30-02, 11:41 AM
#19
Originally posted by peacekeeper
Well guys it may cause the rotary to run bad but the crew cheif I talked to for this indy racer said the more lean they run the better gas mileage but lower hp, and the richer they ran the morehp and shity gas mileage. He said going from way lean most of the race to ful rich adds like 50-60mph for the last and fastest lap. If they aren't on a caution the last lap. Thats how the guy at the indy 500 won this year. he went ful lean and dumped as much fuel as he could into the engine with out flooding it. then the caution came out on a back turn and he coasted in for the win on .04 gallons on gas. He didn't make it to the winners circle thing. the car died on the victory lap. Thats what I was told.
Charles
Well guys it may cause the rotary to run bad but the crew cheif I talked to for this indy racer said the more lean they run the better gas mileage but lower hp, and the richer they ran the morehp and shity gas mileage. He said going from way lean most of the race to ful rich adds like 50-60mph for the last and fastest lap. If they aren't on a caution the last lap. Thats how the guy at the indy 500 won this year. he went ful lean and dumped as much fuel as he could into the engine with out flooding it. then the caution came out on a back turn and he coasted in for the win on .04 gallons on gas. He didn't make it to the winners circle thing. the car died on the victory lap. Thats what I was told.
Charles
05-30-02, 08:29 PM
#20
Thats not an FC...
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richer does not mean faster. it means slower.
see, you run FASTER when you lean it out. when you lean it out, the flame gets hotter, and since its hotter, it expands more, pushing more against the piston. the problem is that when you lean it out too much, it gets too hot.
you can enrichen things to get rid of knock and cool your EGT's down.
for instance, when tuning a DSM, say, your EGT's are 900*c at the top of 3rd gear and you have a knock count of 40. you need more fuel.
add more fuel via AFC, your egts will go down 50-100*C, your knock will go down to 20, maybe lower. you have more fuel.
the way this makes you faster, is that you can run more advance, since the knock is subdued due to the lower cylinder temperatures, so you dont have hotspots which will auto-ignite the mixture in remote places in the cylinder.
adding fuel to an unchanged set up makes you slower, it slows the burn cuz there is more fuel to burn. if it doesnt all get burned, then you have black exhaust. more soot in the tail pipe.
but the problem w/ Rotaries is that you can really have any benefit from advancing timing. especially since that these engines should be tuned for zero knock anyhow. the instant you have knock or detonation, is the instant you need a rebuild. so you cant really have any gains from tuning out knock.
and FYI, the lead in gas, isnt really a dissolved pipe...its called Tetra-ethyl lead
TEL.
but seriously tho, if dumping extra gas into your rotary was so great, then how come we dont ALLLL run 550 injectors on our NA's as Basic performance upgrades???
chris
see, you run FASTER when you lean it out. when you lean it out, the flame gets hotter, and since its hotter, it expands more, pushing more against the piston. the problem is that when you lean it out too much, it gets too hot.
you can enrichen things to get rid of knock and cool your EGT's down.
for instance, when tuning a DSM, say, your EGT's are 900*c at the top of 3rd gear and you have a knock count of 40. you need more fuel.
add more fuel via AFC, your egts will go down 50-100*C, your knock will go down to 20, maybe lower. you have more fuel.
the way this makes you faster, is that you can run more advance, since the knock is subdued due to the lower cylinder temperatures, so you dont have hotspots which will auto-ignite the mixture in remote places in the cylinder.
adding fuel to an unchanged set up makes you slower, it slows the burn cuz there is more fuel to burn. if it doesnt all get burned, then you have black exhaust. more soot in the tail pipe.
but the problem w/ Rotaries is that you can really have any benefit from advancing timing. especially since that these engines should be tuned for zero knock anyhow. the instant you have knock or detonation, is the instant you need a rebuild. so you cant really have any gains from tuning out knock.
and FYI, the lead in gas, isnt really a dissolved pipe...its called Tetra-ethyl lead
TEL.but seriously tho, if dumping extra gas into your rotary was so great, then how come we dont ALLLL run 550 injectors on our NA's as Basic performance upgrades???
chris
05-31-02, 12:30 AM
#23
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Interesting statement there "bambam7", what was it, "The thing is, most s4's have a lot lower compression than when new.... all the ones I've driven have, and damn they're slow... "? Well only thing I can figure is that you have driven the worst s4's on the planet OR those million dollars worth of mods on you rex have jaded you! I say this because the s5 are basically the same as the s4's, with age brings lower compression. And "damn there slow.."? That sounds like something I you would hear from the owners of the FD's when they talk about the s4 OR the s5! I have a 88 TII w/ 95K on it and the owner of that last Mustang I took out a few weeks back would certainly disagree with you here!
05-31-02, 01:18 AM
#24
Originally posted by TurboHead
Interesting statement there "bambam7", what was it, "The thing is, most s4's have a lot lower compression than when new.... all the ones I've driven have, and damn they're slow... "? Well only thing I can figure is that you have driven the worst s4's on the planet OR those million dollars worth of mods on you rex have jaded you! I say this because the s5 are basically the same as the s4's, with age brings lower compression. And "damn there slow.."? That sounds like something I you would hear from the owners of the FD's when they talk about the s4 OR the s5! I have a 88 TII w/ 95K on it and the owner of that last Mustang I took out a few weeks back would certainly disagree with you here!
Interesting statement there "bambam7", what was it, "The thing is, most s4's have a lot lower compression than when new.... all the ones I've driven have, and damn they're slow... "? Well only thing I can figure is that you have driven the worst s4's on the planet OR those million dollars worth of mods on you rex have jaded you! I say this because the s5 are basically the same as the s4's, with age brings lower compression. And "damn there slow.."? That sounds like something I you would hear from the owners of the FD's when they talk about the s4 OR the s5! I have a 88 TII w/ 95K on it and the owner of that last Mustang I took out a few weeks back would certainly disagree with you here!
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