Building the Ultimate Dirt Modified Race Engine: Insider Secrets Revealed!
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- Опубліковано 9 сер 2023
- Please Note: In the video I said valve lift is 1.08 inches for the intakes and 0.968 for the exhausts. This was a mistake. The correct valve lift numbers are 0.720 and 0.645. Thanks!
Jami Stoen and Stoen Racing Engines specializes in the USMTS Dirt Modified race engines, and he was kind enough to let us in on the process. What's most interesting here is how you build an engine capable of winning races around the very limited intake and exhaust ports of the spec heads mandated by the rules. Also, special thanks to World Products and Erson -- www.pbm-erson.com/catalog/worl... -- who were a big part of this build.
Stoen Racing Engines: profile.php?...
Links to some of the products used in this video (Pleae note The Horsepower Monster may be compensated for purchased made through these affiliate links, so thanks for your support!)
Callies Compstar Crank -- amzn.to/3qjYeQF
Water Pump Pulley Kit -- amzn.to/3QAG9s9
Wehrs Machine Water Neck Spacer -- amzn.to/3KywmPu
Super Victor Intake Manifold -- amzn.to/44ZmSF8
Champion Racing Oil -- amzn.to/3s8pUsc - Авто та транспорт
Back in the early 2000's, I campaigned a sportsman car. I ran a 468ci BBC that made 632lb/ft. torque at 3200rpm & 437hp at 5700rpm. I was limited to cast iron heads & 500 Holley 2bbl carb.
Unfortunately, most tracks have a 360ci engine limit now. But it was really fun back in the day, when I'd be running a .583 gear, compared to the SBC boys running 6.50's & 7.00's, and I'd pull them out of the corner, on the inside line...And I'd never get above 6700rpm. That engine lived 12 seasons without ever touching it.
My dad put a big block in my street stock back in 2001ish, i was just 16. But that motor ran....forever lol
That hydraulic tool on the damper was made from a Greenlee punch kit that electricians use. He just modified it
Continue to love your videos!!! That, and an 8000rpm SBC is always a treat for the older generation.
Hey thanks! And thanks for watching!
And all generations too
back in the 90s before i got married and had a kid, i dragged my VW in a pure street class. i will always say, a mechanic and an engine builder are two very different things. i can't even tell u how many times i had my case open, building me an engine, helping other build theirs. having a father and mother both driving VWs. loved your video. i know the time it takes to film and edit them, again thank u.
Hey thanks! And thanks for watching!
I always look forward to your uploads. The in-depth explanation and focus on the details are great. Great video, as always. 👏 👏 👏
Hey, thanks a lot! And thanks for watching!
I started racing imca mods last year and to be honest, I'm not too educated with engines and performance but I appreciate your informative video. My dad has always built his engines and im trying my best to learn as much as I can to at least be knowledgeable of what I'm running and what I can improve on within imca specifications, I can't just race a car and not know or understand what I'm working with. Thankyou again for the video
Absolutely excellent content! Love how you do the voice overs and explain everything. ❤
Thanks very much! And thanks for watching!
Is my happy birthday
@@TheHorsepowerMonsterGold again!!!
Great Content! I run an A-mod under UMP sanction. My motor is from Mullins Race Engines, same bore & stroke, 23 degree heads, 720HP with a 9200rpm redline.
Nice!
The Mullen that Pro Stocked LA Mopars?
I love all these monsters you make!!!!! Please continue to make more of them and fight against electric vehicle propaganda!!!!!
Well put!
@@robertwest3093 thank you
Brilliant show extremely well made and super informative, also glad to see you back. All the very best from Scotland
Thanks! And thanks for watching!
Awesome video !would love to see more. Love all the attention details.!
Can't deny -- that's some good HP from that setup intending 1500 laps of durability!!! Nice work! Be Safe
Welcome back chief. I have missed your videos like this
My husband would go nuts for a motor like this . Dirt racing is his game.
Great build and as always fabulous presentation.
Thanks!
Great knowledge we build ours very similar . Definitely great attention to details and can't wait for the next build
Always is amazing watch those engine builds. I hope soon you do some video of another style of engines (4, 6, cyl).
what a cool build sounds awesome....
Definitely a good rule of thumb for piston to valve clearance .
Great watch .
Ross designed a 1 off set of custom pistons for my buddy's 850+ hp, 440ci small block Olds Super Comp engine with deck clearance, gasket thickness, valve size, cam lift, install timing point & valve timing all considered into the design. Advancing reducess the exhaust valve clearance & retarding reduces the intake clearance. Pretty simple engine building rules. Piston to valve clearance is THE limiting factor on valve size, valve lift & cam timing for Chrysler hemroids, which only make more HP than a wedge head engine when they have a huffer or hair dryers on them to make up for the much smaller cam & valve size they are limited to.
Amazing at full sing
Got bless American engine builders and machinists
Awesome buddy....... Greetings from india 🇮🇳🤠🤠🙌🏻🙌🏻🤘🏻
I really love these videos keep up the great work
Hey, thanks!
Best music I've ever heard!!
Thats some great torque numbers!
Love those small blocks.
That would be a fun 4 speed drag car motor. I know it’s not a drag motor but anything can be a drag race motor if that’s what you have
Nice job, Jeff!
Hey thanks, John!
In our circle track car, we run a vortec headed small block, that engine y'all got is a monster
Very cool
Bom dia, daqui da América sul, aprendo muito vendo os seu vídeos, pois sou mecânico também. Fico feliz por dividir seu conhecimento com todos, um dia terei um V8 e se Deus me abençoar vou visitar a USA e se vocês permitirem visitar a oficina de vocês. Fiquem todos com Deus um forte abraço do seus amigo da América do sul.
Those cam specs are absolutely gnarly. 106 LSA HOLY SHITTTTT
Since you're on dirt track stuff (kinda). Should build a racesaver 305. Can be built following spec under $8,000 and Built correctly they can last well beyond 10,000 laps of abuse without lower end work.
305s don't make any power because the bore is too small which limits the valve size & air flow into the cylinder. A 302 will slay a 305 in the HP department! Also, it costs the same to build any performance engine, regardless of manufacturer or displacement, & usually considrably more to make power with a smaller engine. The key to max HP for the displacement is the biggest bore the architecture will accomodate with the shortest stroke to accomplish the displacement goal. 500ci NHRA Pro Stock engines are 4.700" bore with a 3.600" stroke & make 1500 hp. Would make more if they'd go back to carbs with a tunnel ram intake. Some NHRA Comp Eliminator cars have tiny boosted 4 cylinder engines outrunning big motors BUT they end up costing many times the price, & need to be continuously rebuilt with a fraction of the runs of a big motor.
@@bradgriffith4231 tru but these are engines specifically for bottom tier sprint cars. The class was created to keep cost down to keep the every day working man still in the sport without breaking the bank. Id love it for ford to get their nose in the game more but so far they have only been in the 410 world. The 305 racesaver class is approved to use specific engine stampings to keep every one on the same playing field and leave driver tactics and setup the main factors of racing. There are no videos out there of them on builder channels. Just thought it would be a nice change and something different. They are not a hp driven class either. Hp is great and sure helps get around the track but most of the class is longevity and just to have fun.
Speedmaster wants 1500 plus for a lousy 305 block. I used to dump them in alleys lol
@@williamwertman24 To save costs.....tell that to Speedmaster who wants 1500 for a 305 block
Same cam I have in my street 385sbc, 108 instead of 106
Are those 23 deg heads?
Wow - what a song at 8 grand 😊
And Thanks for all the specs and details on the build - for an amateur like me (from Europe) it is great to learn more about what and how the specific build works.
Question though: if peak power is at 7000 for example, why rev it to 8400 ? Is it faster on the track to keep it at high revs or are there other advantages?
Very interesting to hear your answer. Normally many would keep revs around peak power to get highest effeciency regarding power and friktion losses.
Great Channel 👍🙂
Peter - Denmark - Europe
Im just guessing, but they probably dont shift once they've got the car up to speed. Shifting takes time, and if they upshifted only to downshift into a corner they may lose more momentum and time than they would gain from the additional power available by keeping it closer to its peak. They will have the transmission and final drive gearing configured in such a way that once they get into a gear, 2nd, 3rd, 4th, whatever it may be, they just drive it around with the throttle; Never hitting the redline at the fastest point, while giving them the best acceleration out of the slowest point. With the engine modified the way it is, specifically the water pump drive ratio, its also possible that if you ran the engine hard for a long period of time at a lower RPM, there maybe insufficient water flow to keep the engine cool. So somewhat paradoxically its easier on the engine to live life at 8000. Its been designed to do that.
Thanks for the answer.
It makes sense to be in the sweet spot to accelerate out of corners at peak power and not change gears - and also regarding cooling.
Please keep up the amazing work you do 👍🙂
That sweet 8 grand will cost you an easy 20-25 lol.
Great work anyway
I'd love to have that in my gbody cutlass with little smaller cam to bring low end power up that thing would last forever
You should have my buddy's 1 off 850+HP All Motor small block Olds engine in your Cutlass. He's won Top Rocket at the Olds Nationals every time he's gone! His latest ALL MOTOR 440ci SBO went 5.47/125 in the 1/8 mile first pass out of the trailer with the converter stalling 1000 rpm low. Smoked a twin turbo SBO by .3
@thehorsepowermoster you should check out a 15 or 18 degree 421 ump build motor and compare differences i know spec racing engines builds them just be a cool video as well
That thing rips holy shit, amzing sound at 8400
Great video!! If possible could you do one on a sprint car engine?
An engine is an engine regardless of application or manufacturer. The only difference in a sprint car engine is the cranks have the center counterweights removed because they aren't needed to smooth out low rpm vibration, & also to lighten the crank which improves both acceleration & decceleration. My buddy builds street car engines, trailer towing engines, boat engines, drag & other racing engines & the same rules apply to ALL! The only difference is compression & cam timing for the intended use. He MUST know something because Reher & Morrison told him his Triple Nickel BBC made 50 HP more than theirs when he sent them his 7.97/168 time slip from his All Motor, single Pro Systems carb, 118 race gas, with 4,000 ft air density, 87 Olds Cutlas S/C car. His new All Motor 440 Olds small block went 5.47/125 in the 1/8 mile(equates to an 8.30 1/4 mile pass), first pass out of the trailer with the converter still setup for the 555 & stalling at only 5400 rpm. It was the quickest fastest Olds powered car at the Olds Nationals 2 weeks ago with a twin turbo SBO .3 second slower & only 1 car, a Super Comp Cutlas with a 632 BBC .3 quicker. Would have been much closer to the 632 & would have been .5 quicker than the twin turbo car if the converter stalled at 6500. Converter is going to Hughes to be changed before the car races again.
I’m building a 602 crate late model , I have a new in the crate motor I’d like to know what magic Jamie could do get more hp out of it
What was the oil pump you guys used?
Nice work! As an automotive machinist I feel that every video like this should be prefaced by a kind of warning label ⚠️ that crankshaft rotation should only be judged once the main bearing caps have been properly torqued preferably without the front or real seals in place. I've seen a few engines come back with the customer complaining the crank wouldn't turn when the mains were either hand-tight or not on at all. This might seem obvious to you and I but to a lot of people it isn't.
As a Senior Master ASE, Mod racer and former Tech inspector I don't ever remember anybody bringing back an engine to a shop I've worked in or known having non torqued or missing main bolts. Where do u live where this problem occurs?
you should check out McGunegill Racing Engines in Muncie Indiana
I'd love to run that on the street!!! That be a fun ride in a G body for sure!!!
Great video! Do the rules not allow for a flat plane crank? With that much RPM you would think someone would consider going that route.
Flat plane cranks aren't all that GR8. They don't make the torque at lower RPM as a 90* crank & the vibration harmonics are terrible, like 2, 4 cylinders engines fighting each other! The longer the stroke, the worse the vibration! Ford quit making their FPC Coyote engine after only 1 year & Chevy is only building it so it's a legal engine in the Vettes for the production classes in sports car racing.
@@bradgriffith4231 agree some things just dont work out well in a street engine
Id get the "Why dont you use " comments too, knew better at the time
So Jaimie is really good with a torque wrench.
That thing sings
What oil did he use for this engine?
Maybe do a shop tour next.
Whats with the dyno graph all peakie?
Ya don't turn 8500 & make big hp with a straight line dyno graph! LOL If you ever notice, Engine Masters never start their pulls below 3500, which is BS if ya want a real street motor. A real street engine never sees the rpm where it makes power on the street if it doesn't start making power just off idle. High rpm street motors are for tiny little jap & spaghetti car engines.
See ya!
Also I’m curious how does .450 X 1.6 equal 1”+ of gross valve lift? That equals about .720 you stated .450 and .430 lobe lift with 1.5 and 1.6 rockers or did I miss something?
Your right, it does not add up
Those heads look pretty good. In SCCA the spec heads they made us use were pretty sad. They flowed less than a stock double hump head, you can't do much with that
ouch!
"Double Hump" heads are actually pretty good & can hang with any head available with similar sized ports. The big difference in the older heads & the latest technology "fast burn" heads is in the combustion chamber design which is more efficient & requires less ignition timing lead to make power. Bigger ports make more HP, as GM has learned with the LS & LT engines. The little 4.8 has 200cc ports which were considered huge for a 295 ci every day motor a few years ago. The biggest factory production SBC head only has 170cc ports, while the biggest port SBC GM performance heads are 220cc.
@@bradgriffith4231 Still think those heads are way too big for a 4.8 and 5.3
Engine was one soggy dog just had 0 torque. Cant help but wonder if they cast a good 180cc head for those 2 how they woulda run . Beancounting prevented Im guessing
We have a bunch of truck pullers here now running big blocks and turning them 10 to 10.5k !!! They super expensive and are high maintenance.
Sonny's or Steve Schmidt 648 / 650 cu Modified truck puller engine gonna set a guy back $80K! But oh do they run!!
Sonny's or Steve Schmidt 648 or 650 cu truck puller engine will set you back 80K+ but oh do they bring the mail!!
Sorry for double post! Had severe delay in posting? Thought it didn't post so did it again.
I can just imagine this engine in my 92 S10 4x4 5speed 2 door... But that's all I can do is imagine I know I will never get this beautiful engine or anything close to it
I hear ya. Been dreaming about an SB2.2 or at least do a nice 18 deg sbc just too old to start working again to earn the $
Sure would be nice to add another 80-100 same CI
Polish intake runners?
What does something like this cost?
You want to hear music listing to a baby 302 sbc 13 to 1 at 9 grand that's a beautiful sound
Man that engine was singing!
how much is it to build this motor?
I wonder how much power is stuck in those heads?
probably over 150
Why don't you install bigger push rods and stud griddles with that high of spring pressure it can't look very good under them valve covers
Oiling system is insane.
you put the intake on backwards....lol.... can you race FORD motors?
Can you explain what determines how high a engine can turn. I've asked a few people and no one has answered me.
Cylinder heads and camshaft. Period.
It's all in the valvetrain and cam duration, .260 at .050 lift is what this cam is and you can see it actually stops making hp around 7000 and starts down but the huge valve spring control the valve enough to carry out to the higher rpm
mainly it´s valve train control and the strenght of the rotating asembly, valves can float, meaning the spring can´t return the valve fast enough and it mets a piston. Soo basicly you don´t want valves and pistons to met and exploding and cracking rods, pistons and crank is also bad. The stronger and ligther the materials the faster an engine can spin, too heavy means too much momentum that puts a lot of stress in the material and leads to material failure, too ligth may be not strong enough, soo you spin it as fast as you dare before braking it.
@@dirtfan05exactly right
Piston speed is what matters. Google max piston speed then then use an online calculator to determine piston speed per rpm
I’m leaving to horsepower and torque should be going up a little bit further than that on the rpm range. It just keeps dropping down goes 400 hp when you get up and then rpm range.
Everyones thinking "This will Last 1500 laps!......mmm....that is to and from my work place for 3 years......... wonder how this would do as my daily?"
It would do poorly. The concessions made to be able to operate at 8500rpm will manifest...immediatly...
Lasting 1500 laps with that spring pressure and no stud girdle or better yet shaft rockers not likely.
What is the lobe separation angle on the cam?
106 lobe sep
@@TheHorsepowerMonster Thank you!
That's the angle between the intake lobe & exhaust lobe center lines. It is determined by the duration. It controls the int/exh "overlap" & the rpm where the engine is most efficient for the predetermined power band one is seeking.
@@bradgriffith4231 Yeah, I wondered what the number actually was. He said what the intake centerline was, but if he said what the LSA was in the video, I missed it.
Shoutout to everyone who would like a re-do on that waterpump install..
I'm trying to figure out what was wrong with it? I am a Ford guy, so I didn't notice anything off.
Shake 'n' Bake!
It would be cool if you could show an Outlaw Sprint engine build! Chances are they WON'T because people pay near on 100k to have an engine built that just has 5hp on everyone else if it means victory!
That would be a fun build!
Your price estimate is about double what a sprint car engine costs, $40-$50,000. I've had several friends over the years who were Sprint car engine builders & several who were Outlaw car owners. NHRA Pro Stock & NASCAR engines are the most expensive(other than F1). A set of Pro Stock heads cost about the same as an Outlaw motor, around $50,000, & NASCAR engines have every part in the engine cryo treated(to the tune of $7 per pound) for material consistancy & longevity.
Nice video, sure would have liked to have saw Jamie use a rod bolt stretch gauge instead of a torque wrench on those rod bolts tho!
He does like I do and installs the cam first.
That hydraulic balancer installer looks like a modified hydraulic exhaust pipe expander tool. The center piston is threaded and it pulls inward on the threaded shaft pulling the body into the balancer and forcing it on.
Looks like a Greenlee knock out that electrician use.
The harmonic balancer isn't even necessary except to help seal the motor. It works at idle & does nothing once the rpms are up. They don't even run a balancer on a sprint car engine or top fuel drag race engine. It's replaced by solid steel accessory drive hubs to run the mechanical fuel pumps.
Drink at his catchphrase "Jamie said"
That hydraulic balancer installer could be made by using a hollow ram port a power
Guy building the engine looks like a friend of mine Todd clyne
450 thou lobe lift x 1.6 rocker ratio = 720 thou lift not over 1inch
You are absolutely correct. When working on my script I wasn't careful enough and looked at valve lift on the cam card and read it as lobe lift. It is .720 intake lift and .645 exhaust valve lift. My bad!
Depends on where ya race. Some locales favor crate motors, some built open motors. ARCA & the NASCAR trucks are almost all running the ILMOR LS396 crate motors, regardless of manufacturer. Kyle Busch said his Toyata trucks couldn't hang with the ILMORs so he switched over. Just like IMCA, they chip the open motors to be more equal to the crate motors. So why spend $40,000 building a high HP engine when ya can buy a $7,000 CT400 crate motor? Also, I know the technology pretty well & understand the suspension, but how much horsepower can ya really hook up with an 8" wide tire?
Very interesting. Go back 52 years and rev a Clevland to 7000 and have fun. Yet to do that, building one now.
Adding 2° degrees & only gaining 2 numbers? I don't understand why they didn't say anything about that. I'm no engine builder or a great tuner, but that doesn't add up. Why leave it there at 36°? That's very risky in my opinion, especially when the engine is as cool as it is. Its going to be much hotter & susceptible to knock/detonation after it's heat soaked or hot laped. Anyone have a opinion or comment?
Current technology "fast burn" heads don't require as much ignition timing lead as older stuff & more timing makes very little difference. My pump gas 409ci SBC street car engine makes the same power at 32* as it does at 36*. Engine Masters tested a half dozen different octane gases on a dyno & regardless of 87 octane or 118, the jetting & the timing NEVER changed, nor did the torque or horsepower. The least timing needed to ignite & burn ALL the fuel in the cylinder makes the most power because the earlier the spark occurs, the more pushback there is against the piston as it approaches TDC.
@@bradgriffith4231 That's what I'm saying, I would run it at at the least necessary timing if they made the same or similar power. Adding 2 degrees for 2hp is ignorant right? That's a good cushion for heat or less detonation resistant fuel you may unknowingly get.
@@danieljames5875 Do things the exact same way. No sense in searching for power thats non existent...gettin greedy
For some reason guys will STILL try and fool themselves into beieving they are missing out by not running excessive timing
23:55 is it just my eyes.....
.
or did that entire motor move backwards????
yes it sure is dancing back and forth! probably why the dyno chart is all jagged
I was doing 2800 rpm at Desoto speedway 3/8 mi high bank in a STREET STOCK 350/360 HP ENGINE LOL
Whats the point of running it 2,300rpm past its peak power
If you pay attention to the horsepower readout during that pull it was still making 500hp at that rpm... that's still very useable power down the straight away, you can't have a broad enough power curve in a circle track engine, they use it all and then some.
Dirtfan05 is exactly right. Circle track race engines have to be able to pull through a wide rpm range. From the point the driver gets on the throttle coming out of the turn until the end of the straight the engine may rev from 4,500 or 5,000 rpm and be bumping against the rev limiter at 8,400 by the end of the straight. So they spend a lot of time on both sides of peak power.
Because HP is "Torque times RPM divided by 5250 = HP". There's more flexibility with a circle track engine if it will carry the torque past peak HP. It will theoretically be a bit below peak HP coming of the turn & still be able to accelerate & run to the end of the strightaway.
Like other comments...why aren't the curves smoothly arced?
Looks like a problem.
Engines NOT pulling smooth.
Block needs work. Your asking for windage, from oil drain back.
You don't chamfer oil holes on rear main cap ??
Is it just me or does that cam sound a little short on duration for an 8500 rpm engine. I'm ignoring lift as I assume that's limited by the sanctioning body.
You must be some kind of genius if you can tell the cam specs by the sound of the engine! LOL My buddy's All Motor 8500 rpm 440ci small block Olds runs about a 276* @ 0.50 cam to make 850 hp on gas with a single Pro Systems carb.
@bradgriffith4231 you would be a smart ass after it's been too long to remember what I was thinking when I typed that. Genius, yes, but my hearing is way too bad for that. I'm sure I type that comment in the space of time between him saying the duration and then finally saying @ 0.050. Could be that I'm just dumb. Hard to say so long afterward.
I know it's class rules but, its a shame that short block and cam is sooo limited by those heads.
I want one cuz.
Is this a 350 Sbc
yes
@@TheHorsepowerMonster thnk u for the fast reply
I’m building a 1400hp LS right now. I’m expecting 9000 rpm shift. I’ve been a sucker for high rpm engines since high school.
#23degreebadass
How can I get a giveaway. I blew my engine last year after I built a brand new car. Can't afford another engine soi haven't been able to Race
Then you can’t afford to race.
What happened with the vett
It shoved into a corner while I worked on other projects. Got to get back on that thing!
America!
I think you need to recalculate that valve lift my math doesn't quit come out that big
Correct. I looked at the wrong spot on the cam card and multiplied the rocker ratio by the valve lift number on the card instead of the lobe lift.
Jamie says
small block V8
Shit, I had an 10,700rpm destroked 400 sbc in my street/strip 87 Monte Carlo. With a Jericho 4 speed and a 9 inch. I drove this car to high school in 1997. You should hear a push rod engine at that rpm
You needed a new tach or to reset it to 8 cylinders instead of 4! NASCAR engines only turn 8500-9000 now & Pro Stock engines 10,500. If you could afford a 10,700 rpm engine in HS you must come from a family of millionaires! LOL That bullsh!t could be outrun by a real street motor that make power from just off idle to 6,000! My buddy only turns his LOW 8 second, 850hp, 440ci small block Olds 8,500 & I bet his 1 off Batten heads cost more than your whole engine!
I assure you that the tach was accurate and my engine was extremely over square and the heads were very similar to nascar SB2 heads. A heavily modified tunnel ram with 2 dominators. While a stock car engine can turn 9,000 rpm for a few hundred miles, I spun mine almost 2,000 rpm higher for a couple thousand feet. I’m not the only one to have done this, just search UA-cam and you’ll find plenty of videos of people doing the same thing or higher. Plus I only had 1,086hp and 674tq in a 2,900 pound car and I was running 9.30s @ 148. Lots of people are quicker and faster. And my build was more similar to land speed cars. But I really appreciate your concern about my instruments being faulty, always wise to verify settings and wiring.
Todays high end oils you don’t need 20/50. Daytona1 performance full synthetic 10/30 will protect well over 300* oil temp and free up 8+ hp over 20/50 syrup.
Bearing clearance has a lot to do with oil viscosity needed. NASCAR guys & NHRA Pro Stock run 0 wieght. I wouldn't recommend it in an engine not designed for it, but I'm sure you know more about it than real professional engine builders! LOL
You should watch the engine masters oil shoot out. 20/50 hot made more power than 10/40
(8) O2 sensors for a carbureted engine ?!!
Just for tuning on the dyno. Not used on the race track
Hmmm... A Very Tough and Powerful Englne. I wouldn't want to have to Pay For the Race Fuel Though. Ha ha!
Depends on quantity what fuel is required. My buddy runs 118 octane in his SC Cutlas & burns 1 quart per pass. 2 gallons or so for a normal race & by far his lowest cost expense.