need blower cam suggestions

[IMPATIENT 1]

i got some 990's for the blower mill i'm building finally ordered and i need a cam recommendation from you guys.here's some specs:
9 to 1 bbc roller 475
dual boost referenced 750's
6-71 making 7-8lbs boost
990's rect. portwith 2.25 1.88
either goin b cut or ab cut on the impellor(pump: dominator pump,droop,inducer,shoe/ride plate,divertor)
i'd like to get my tx-19 into triple digits, and still come outta the hole like a rocket.want to take it easy on the valvetrain too, some thing with less than 690-700 lift.boat will see alot of cruising and cove racing.

[IMPATIENT 1]

another Q., what kinda power do you guys think this set-up might have? i need at least 750-800hp to do what i want, and i can set-up the boat/pump up to do the rest.

[Daytona100]

9.1 comp 8 lbs boost no chiller what gas are you going to run?

[IMPATIENT 1]

9.1 comp 8 lbs boost no chiller what gas are you going to run?
avgas , race fuel

[Daytona100]

PM Cstraub on the boards he will make one custom for your application.

[IMPATIENT 1]

PM Cstraub on the boards he will make one custom for your application.
i thought about that since i got pistons from him at a great price. i don't even know where to start as far as specs though to order a custom cam for a blown application.i want the most power i can get outta these heads and still have some torque.

[Daytona100]

You just tell him the specs and he will figure it out.

[boatnam2]

i thought about that since i got pistons from him at a great price. i don't even know where to start as far as specs though to order a custom cam for a blown application.i want the most power i can get outta these heads and still have some torque.
call clay smith cams in anaheim,guy has been building blower motors for 40 years and grinds his own cams.

[DMOORE]

Just a thought, add a chiller and bump it up to 10psi.
Darrell.

[Daytona100]

Just a thought, add a chiller and bump it up to 10psi.
Darrell.
What comp are you running?

[DMOORE]

What comp are you running?
Mine is 7.5, but I only run 91 octane.
Darrell.

[blownzoom440]

Just a thought, add a chiller and bump it up to 10psi.
Darrell.
to get 10 psi intake dont you need 14 on the blower side? [due to restriction/temp drop.]

[DMOORE]

to get 10 psi intake dont you need 14 on the blower side? [due to restriction/temp drop.]
Ya know, I'm not sure. The boost guages on my motors are plummed in down on the manifolds, so I don't know if there would be a higher reading just under the blower. But a 4psi drop seems like a lot.
Darrell.

[VDRIVERACING]

A blower cam is going to have a lot less overlap, and a wide lobe center (112-114 degrees). It may also have a longer exhaust duration, and no more than 650 lift(roller cam), roughly, will do the trick and help your valve train live. It pays to do some reading up on this area.
I strongly suggest you get some dominators. 750's just dont feed blowers that well. Probably gonna hear "it worked for me" from someone, but once you bolt on the big venturis you'll know why I suggested it. It will allow you to overdrive less(OR ALL YOU WANT!!!), and get more boost through a wider range. Now, with the big carbs in place, giving that pump what she's asking for, you're positioned for a superchiller--if you want to shell out a couple more grand. If you're down for that investment, the coolers can add another 40HP right quick...

[IMPATIENT 1]

A blower cam is going to have a lot less overlap, and a wide lobe center (112-114 degrees). It may also have a longer exhaust duration, and no more than 650 lift(roller cam), roughly, will do the trick and help your valve train live. It pays to do some reading up on this area.
I strongly suggest you get some dominators. 750's just dont feed blowers that well. Probably gonna hear "it worked for me" from someone, but once you bolt on the big venturis you'll know why I suggested it. It will allow you to overdrive less(OR ALL YOU WANT!!!), and get more boost through a wider range. Now, with the big carbs in place, giving that pump what she's asking for, you're positioned for a superchiller--if you want to shell out a couple more grand. If you're down for that investment, the coolers can add another 40HP right quick...
man , i'd love to run some dominators, but this yrs. budget isn't gonna allow for it.this set-up is by no means what i want , just what i can afford this yr..i wanted some canfileds but found a smokin deal on some 990's with good work already done to em, so i settled.i still gotta go thru the pump, buy and have inducer installed, rip out the subfloor and ski box, then do carpet(for my family's feet,lol).
i bought this boat for 7500 in late sept., and it was "supposed to have" a fresh roller 468. i tore it apart after 1 trip to the lake to find a cast crank turned 30/30. closed chamber dome pistons(that got nicks from the open chamber heads), fresh 781 oval ports with stock size valves.had a nice roller cam set-up though.the dominator pump was WORE OUT:mad: so i'm trying to keep this yrs. upgrades to a tight budget.it topped out at 78mph at 5500 , wore out b dominator impellor with this mill.i'll be stoked with a mean holeshot and 95mph with this yrs. upgrades.if i meet my goal, i'll get to work on 105mph next fall(heads, dominators, and possiblly a 8-71).

[Blown 472]

man , i'd love to run some dominators, but this yrs. budget isn't gonna allow for it.this set-up is by no means what i want , just what i can afford this yr..i wanted some canfileds but found a smokin deal on some 990's with good work already done to em, so i settled.i still gotta go thru the pump, buy and have inducer installed, rip out the subfloor and ski box, then do carpet(for my family's feet,lol).
i bought this boat for 7500 in late sept., and it was "supposed to have" a fresh roller 468. i tore it apart after 1 trip to the lake to find a cast crank turned 30/30. closed chamber dome pistons(that got nicks from the open chamber heads), fresh 781 oval ports with stock size valves.had a nice roller cam set-up though.the dominator pump was WORE OUT:mad: so i'm trying to keep this yrs. upgrades to a tight budget.it topped out at 78mph at 5500 , wore out b dominator impellor with this mill.i'll be stoked with a mean holeshot and 95mph with this yrs. upgrades.if i meet my goal, i'll get to work on 105mph next fall(heads, dominators, and possiblly a 8-71).
How bout a hilborn???

[IMPATIENT 1]

How bout a hilborn???
WAY beyond budget:D

[VDRIVERACING]

man , i'd love to run some dominators, but this yrs. budget isn't gonna allow for it.this set-up is by no means what i want , just what i can afford this yr..i wanted some canfileds but found a smokin deal on some 990's with good work already done to em, so i settled.i still gotta go thru the pump, buy and have inducer installed, rip out the subfloor and ski box, then do carpet(for my family's feet,lol).
i bought this boat for 7500 in late sept., and it was "supposed to have" a fresh roller 468. i tore it apart after 1 trip to the lake to find a cast crank turned 30/30. closed chamber dome pistons(that got nicks from the open chamber heads), fresh 781 oval ports with stock size valves.had a nice roller cam set-up though.the dominator pump was WORE OUT:mad: so i'm trying to keep this yrs. upgrades to a tight budget.it topped out at 78mph at 5500 , wore out b dominator impellor with this mill.i'll be stoked with a mean holeshot and 95mph with this yrs. upgrades.if i meet my goal, i'll get to work on 105mph next fall(heads, dominators, and possiblly a 8-71).
Sounds like you're on the right track. In a car, I always started with the proper rear end/gears, and worked forward. My jet buddies tell me start with the jet, as well. It's a shame to hear about the engine, but if it's any consolation, it's happened to all of us at some point. I bought a 65 Chevelle a few years back with a SBC that was supposed to have the 202 valves. Well, it did have 202 vales, but the seats were only machined for 194's!!
Good luck and be safe with that monster!

[IMPATIENT 1]

aaron ran his dd on the set-up, he said he ran stock 990 flow numbers with the 2.25 and 1.88 valves. i know its not a science but it helps and the last mill i built had more power than what aaron's dd came up with(as per impellor hp absorbtion chart, yep the impellor dyno:D ), i like it and use it as a tool, not a definate dyno run.my uncle has a comp blower cam he said he'd give me(252 262 652 lift 114)here's what the dd came up with on this cam:
Well Impatient, here ya go.
Again, no '990 head flow data other than bone stock so ran Canted Valves, fully ported, large valves.
I also managed to find your cam to confirm the specs you gave me were 50-thou specs.
RPM .... HP .... Tq
2,000 .. 198 .. 521
2,500 .. 278 .. 584
3,000 .. 354 .. 619
3,500 .. 432 .. 648
4,000 .. 517 .. 679
4,500 .. 607 .. 708
5,000 .. 689 .. 723
5,500 .. 739 .. 706
6,000 .. 786 .. 688
6,500 .. 814 .. 657
7,000 .. 813 .. 610
7,500 .. 817 .. 572
8,000 .. 785 .. 515
8,500 .. 750 .. 463
9,000 .. 715 .. 417
whata ya'll think? if i went bigger, won't my torque get to far away from working good with a b-cut impellor?thanks for all the help and advise guys!

[IMPATIENT 1]

got another blower cam from lunati roller i can run if it'll out perform the comp cam i listed above:
i248 e260 680lift 112c (@.50)
the other option is the comp roller blower cam, its specs are:
i252 e262 650lift 114c (@.50)
which do you guys think is the better cam for my set-up? the 650 would be less wear & tear.and what would he centerline differences between these cams be? i've both to pick from, the one i get will be free or really cheap.i know a custom grind would work better, but that can wait till i get some better alum heads for it next fall.my uncle has 3 blower cams for me to chose from, 1 is just to big and not even a consideration with flat tops.i'm confused on which to run, both are nice cams:confused: which would work better for me in my tx-19 spinning a b-cut?

[born2burn]

Call Cstraub.......Chris Straub 4238540007
He will hook you up tell'em born2burn sent ya.

[IMPATIENT 1]

Call Cstraub.......Chris Straub 4238540007
He will hook you up tell'em born2burn sent ya.
i'm sure he could and have talked with him already, but i'm gonna wait on a custom grind cam till i get new heads.the cams listed above are ones i have available to run, with no outta pocket:D or maybe alittle horsetrading if 1 will do the job.

[born2burn]

i'm sure he could and have talked with him already, but i'm gonna wait on a custom grind cam till i get new heads.the cams listed above are ones i have available to run, with no outta pocket:D or maybe alittle horsetrading if 1 will do the job.
Makes a guy wonder why your uncle isnt still running those cams?????? Maybe because someone like cstraub didnt crunch the numbers for "the" specific engine combination????

[IMPATIENT 1]

Makes a guy wonder why your uncle isnt still running those cams?????? Maybe because someone like cstraub didnt crunch the numbers for "the" specific engine combination????
nah, he kept the ones he ran as his hydro motor transformed into the blown injected 540:D he never sells things, so he's got some he's ran over the yrs. in his 454's, 496's, 540's.
payin 450 for a cam isn't an option for me rite now, otherwise i'd send chris my info and know what cam he sends me is the best roller for my set-up.i pay cash for toys and parts for them, i'm never goin in debt on toy parts, kinda takes the fun outta of hobby doesn't it;) plus i'd rather spend the 450 on the pump parts, get the inducer, things like that this yr.

[VDRIVERACING]

nah, he kept the ones he ran as his hydro motor transformed into the blown injected 540:D he never sells things, so he's got some he's ran over the yrs. in his 454's, 496's, 540's.
payin 450 for a cam isn't an option for me rite now, otherwise i'd send chris my info and know what cam he sends me is the best roller for my set-up.i pay cash for toys and parts for them, i'm never goin in debt on toy parts, kinda takes the fun outta of hobby doesn't it;) plus i'd rather spend the 450 on the pump parts, get the inducer, things like that this yr.
That Comp Cams grind looks pretty good. When you're ready for your heads and custom grind, you may also want to consider Isky. They're not going to charge you $450...

[born2burn]

nah, he kept the ones he ran as his hydro motor transformed into the blown injected 540:D he never sells things, so he's got some he's ran over the yrs. in his 454's, 496's, 540's.
payin 450 for a cam isn't an option for me rite now, otherwise i'd send chris my info and know what cam he sends me is the best roller for my set-up.i pay cash for toys and parts for them, i'm never goin in debt on toy parts, kinda takes the fun outta of hobby doesn't it;) plus i'd rather spend the 450 on the pump parts, get the inducer, things like that this yr.
Kewl.........understandable.

[IMPATIENT 1]

That Comp Cams grind looks pretty good. When you're ready for your heads and custom grind, you may also want to consider Isky. They're not going to charge you $450...
i totally understand the need for a custom grind, but i thought since next fall i would be buyin alum heads, why not wait till then to drop the big $$ for the custom.wouldn't be very smart with my $$ if i had 1 ground, then 6 months later need another 1 ground to work with the new heads. i've already dropped outta pocket @ 11k in the last 6months buyin the tx-19 and collecting parts,blower,carbs,pistons,h-beams,990heads, machine work, i just would like to have some $$ left over to put fuel in it this summer:D maybe still afford some keystone to drink,lol.

[MACHINEHEAD]

IMP1 Just to throw it out there. Did a 489- 7.8 to 1/ 8-71/ 2 dominator 990 head/ no porting w/Crane 246/254/112 lda hyd. flat shelf grind. 4lbs boost 735 hp at 5400rpm. Runs all day in a 21 schiada 78-82 mph at 5100rpm. Not very impressive but has lasted 4 years now and the guy is pretty hard on his chit.

[wagspe208]

Blown GAS cams have more overlap. Depending on power output desired. A serious piece will have 108 to 110 lobe separation. Blown ALCOHOL cams use a wide lobe separation. Usually 112 minimum to 114. Reasoning: the gas pieces use the overlap to clean out combustion chamber to a smaller degree, and cool the combustion chamber/exhaust valve. This helps to prevent detonation. Blown gas pieces generate ALOT of heat.
Blown alcohol pieces on the other hand, love cylinder pressure. Alcohol runs much cooler. The wide lobe separation keeps the mixture in the cylinder longer to keep heat in.
I have a sweet blown gas cam in the garage if you are interested. It is an ultradyne roller. Pretty easy on valve springs. I ran it in my river runner jetboat a few yeaers ago.
Wags

[sanger rat]

Wags you have a PM.

[wagspe208]

I still have the camshaft. It's an ultradyne 328/336 R 10. it's on a .950 base. If memory servis it's a .690/ .710 lift. I'll have to call UD and confirm. I just looked at it and it has some surface rust. I will have to see how it cleans up and see if I will sell it. I do NOT sell junk.
I'll be out of town until 3-12, so pm me and I will get back to you in a couple of weeks.
Wags

[VDRIVERACING]

Blown GAS cams have more overlap. Depending on power output desired. A serious piece will have 108 to 110 lobe separation. Blown ALCOHOL cams use a wide lobe separation. Usually 112 minimum to 114. Reasoning: the gas pieces use the overlap to clean out combustion chamber to a smaller degree, and cool the combustion chamber/exhaust valve. This helps to prevent detonation. Blown gas pieces generate ALOT of heat.
Blown alcohol pieces on the other hand, love cylinder pressure. Alcohol runs much cooler. The wide lobe separation keeps the mixture in the cylinder longer to keep heat in.
I have a sweet blown gas cam in the garage if you are interested. It is an ultradyne roller. Pretty easy on valve springs. I ran it in my river runner jetboat a few yeaers ago.
Wags
Recent personal experience compels me to disagree. I was running a gas blown motor with high lift--like your cam--and lower lobe separation. Result: High exhaust temp(because unburnt fuel makes it way out of the combustion chamber and into the exhaust header), and lot's of valve train carnage (high lift sounds sexy, but it's hard on valve train - more suited for short blasts like drags).
After lots of parts changing and frustration, went to an Isky ground 650ish lift roller cam with the wider lobe center. Result: far more torque, runs high rpm with ease, no valve train issues. If you check out Comp Cams, and others, for blown gas motors their recommended specs bear this out.

[wagspe208]

Disagree all you want. .710 is so far from high lift these days. With that duration and little lift this cam will run all year long with a good set of valve springs. I know, I did it.
There are high egt temps on blown gas, that's why the overlap. EGT's are also a function of timing. What fuel were you running? Alot of factors influence egt's besides cam events. Static comp?
I assumed these guys wanted to make power. I had this cam in a river runner jetboat. That being said....I only drove it for 15 to 20 miles at a time. Not all day. This engine, bolted directly in my hydro ran 8.0's with carbs and race gas. It is estimated that it takes my hydro approx 950 to 1000 hp to run that number.
Comp cams are great for shelf motors. If that is what you are building, fine...go to comp and get a cam. Just like go to autozone for a starter. They are cheap, advetise everywhere and decent pieces. I doubt if Steve Schmidt or Sonny Leonard, or pick whoever is calling comp and having the guys behind the desk pick cams.
Wags

[IMPATIENT 1]

i went with the comp blower cam with 255/262(@.050)652 lift and 114 centerline.this boat's not gonna be a dedicated race boat, me and the fam are gonna spend alot of time in it, figured i'd stick with the "easy on my train" theory for now.if i getta pontoon soon and i'll throw a big stick in it and see what'll do then.

[pw_Tony]

avgas , race fuel
Are you sure you want to run Avgas with a blower? Blower's create alot of heat and that's why they are best on Alcohol. But gas works fine too but some gas guys take out the Teflon strips to reduce heat.
Avgas is meant for planes, where it's high altitude and temperature isn't a factor.
Avgas runs much hotter than gasoline, not ideal for a blower that creates heat.
Ask some of the other guys out here, straight Avgas is not a pretty sight when you take your heads off and seen what they did to your pistons and combustion chamber
Stick with race gas or is possible 91, anything's better than avgas, and don't you dare run oxygenated fuel...

[IMPATIENT 1]

Are you sure you want to run Avgas with a blower? Blower's create alot of heat and that's why they are best on Alcohol. But gas works fine too but some gas guys take out the Teflon strips to reduce heat.
Avgas is meant for planes, where it's high altitude and temperature isn't a factor.
Avgas runs much hotter than gasoline, not ideal for a blower that creates heat.
Ask some of the other guys out here, straight Avgas is not a pretty sight when you take your heads off and seen what they did to your pistons and combustion chamber
Stick with race gas or is possible 91, anything's better than avgas, and don't you dare run oxygenated fuel...
nah, i mix av 50% super50% or i run racefuel 110 sunoco, sometimes i may back down the timing some more and run super, if i'm just out with the fam..racefuel has to be bought by the barrel here, so i buy 1 for the summer, that's it.save it for holiday races or meets:D

[pw_Tony]

nah, i mix av 50% super50% or i run racefuel 110 sunoco, sometimes i may back down the timing some more and run super, if i'm just out with the fam..racefuel has to be bought by the barrel here, so i buy 1 for the summer, that's it.save it for holiday races or meets:D
Yeah I know some guys that run 50/50, but usually never straight avgas for a period of time... usually

[VDRIVERACING]

Disagree all you want. .710 is so far from high lift these days. With that duration and little lift this cam will run all year long with a good set of valve springs. I know, I did it.
There are high egt temps on blown gas, that's why the overlap. EGT's are also a function of timing. What fuel were you running? Alot of factors influence egt's besides cam events. Static comp?
I assumed these guys wanted to make power. I had this cam in a river runner jetboat. That being said....I only drove it for 15 to 20 miles at a time. Not all day. This engine, bolted directly in my hydro ran 8.0's with carbs and race gas. It is estimated that it takes my hydro approx 950 to 1000 hp to run that number.
Comp cams are great for shelf motors. If that is what you are building, fine...go to comp and get a cam. Just like go to autozone for a starter. They are cheap, advetise everywhere and decent pieces. I doubt if Steve Schmidt or Sonny Leonard, or pick whoever is calling comp and having the guys behind the desk pick cams.
Wags
The issue was not about what a professional drag racer might choose. I think Impatient1 chose wisely, and will be able to build upon that platform. With a carb upgrade later on, this rig can kick out near 800 HP with torque numbers in the mid to high 700's, and be pretty reliable at that.

[pw_Tony]

Also if some of the cams from different brands are close but just a little off you should think twice about it. Actually even though most cam shops do alot of their grinding in house, tons of their production cams are sent to a giant Cam grinding shop in Chicago, where they grind cams for Crower, Comp, Crane and all the other big guys.
I've learned this from my last job at a engine development shop. We had a "Cam Doctor", which measures the EXACT specs on a cam. And despite what they sell it to you, few times are they actually those specs. We've cam doctored tons of brands of cams. We had a Lunati cam that was quite a bit more exotic than what it was advertised as, and then compared it a Crower cam and guess what, It Was The Exact Same Grind! That is extremely rare to see with the tools to accurately measure a cam.
So when you do pic out a cam don't pick just cause it's a 0.010 lift ligher or a few duration off...
Just a side note

[IMPATIENT 1]

if get a dependable 750hp outta it, i'll be more than happy! i can make the pump do the rest of the work;)

[atxwrangler]

Tom,when i bought the cam for the blown ford,i called bds and told them i didn't want an all out race cam.i was putting together a blown application lake boat that i would race occasionally.they sold me a cam with these specs110 lobe center,intake dur. 296,intake cam lift .370,valve lift .630,EXHAUST TIMING,306 DURATION,CAM LIFT .380,VALVE LIFT IS .645, OVER LAP IS 81DEGREES!:idea: HE told me everyone that bought this cam seems to love it!Idon't know!

[don johnson]

Are you sure you want to run Avgas with a blower? Blower's create alot of heat and that's why they are best on Alcohol. But gas works fine too but some gas guys take out the Teflon strips to reduce heat.
Avgas is meant for planes, where it's high altitude and temperature isn't a factor.
Avgas runs much hotter than gasoline, not ideal for a blower that creates heat.
Ask some of the other guys out here, straight Avgas is not a pretty sight when you take your heads off and seen what they did to your pistons and combustion chamber
Stick with race gas or is possible 91, anything's better than avgas, and don't you dare run oxygenated fuel...
Completely disagree. Avgas works great in many boat/ car applications. I run 100% Av Gas as well have a number of friends with Teague, GT and Pfaff blower motors that run on 100% avgas with Marvel mixed in for lubrication.
I run 2 1,100 HP Teague motors that I run on 100% Avgas. 11 lbs of boost. Been running Av in all my stuff for over 10 years without exception or problem. The big debate on Av gas vs race fuel vs pump gas usually stems from an improperly set up engine (bad tune) which results in a failure and instead of blaming the tune up on the failure the fuel gets blamed.
I have spent many hours tuning my motors on the dyno and with O2 sensors in real life on the water and can tell you first handed that there is little/ no changes in jetting pump gas to av gas or vica versa. However, my motors are set up slightly on the rich side after about 1/2 throttle. Have checked both fuels with O2 sensor and there is little difference in the air/fuel between the 2 fuels. Have also run EGT's with both fuels and they are nearly identical.
Now all fuels have a capacity to support an engine relative to tune, especially blown deals or high compression N/A motors. AvGas does have a higher octane vs pump gas and can support greater timing and/ or boost. Av Gas is however a "dry" fuel with little lubrication qualities. That can be easily addressed by mixing Marvel in. Av Gas with Marvel is an awesome fuel and blower motors like this fuel a lot. The Marvel lubricates the blower strips/ rotors and valves much better then a pump gas fuel ever could. I freshened my motors a while back, sent the blowers to Mooneyham to be restriped and they said no way, the blowers were in like new condition. Additionally, Av Gas has a much greater "shelf life" and does not go bad over time like pump or race gas. Like I said, many benefits to Av Gas.

[IMPATIENT 1]

Completely disagree. Avgas works great in many boat/ car applications. I run 100% Av Gas as well have a number of friends with Teague, GT and Pfaff blower motors that run on 100% avgas with Marvel mixed in for lubrication.
I run 2 1,100 HP Teague motors that I run on 100% Avgas. 11 lbs of boost. Been running Av in all my stuff for over 10 years without exception or problem. The big debate on Av gas vs race fuel vs pump gas usually stems from an improperly set up engine (bad tune) which results in a failure and instead of blaming the tune up on the failure the fuel gets blamed.
I have spent many hours tuning my motors on the dyno and with O2 sensors in real life on the water and can tell you first handed that there is little/ no changes in jetting pump gas to av gas or vica versa. However, my motors are set up slightly on the rich side after about 1/2 throttle. Have checked both fuels with O2 sensor and there is little difference in the air/fuel between the 2 fuels. Have also run EGT's with both fuels and they are nearly identical.
Now all fuels have a capacity to support an engine relative to tune, especially blown deals or high compression N/A motors. AvGas does have a higher octane vs pump gas and can support greater timing and/ or boost. Av Gas is however a "dry" fuel with little lubrication qualities. That can be easily addressed by mixing Marvel in. Av Gas with Marvel is an awesome fuel and blower motors like this fuel a lot. The Marvel lubricates the blower strips/ rotors and valves much better then a pump gas fuel ever could. I freshened my motors a while back, sent the blowers to Mooneyham to be restriped and they said no way, the blowers were in like new condition. Additionally, Av Gas has a much greater "shelf life" and does not go bad over time like pump or race gas. Like I said, many benefits to Av Gas.
i know alot of guys doing that same. i prefer running alittle super unleaded for the added lube, can't bring myself to add oil to fuel:D
avgas is just more affordable to run than race fuel.my boat sees alot more days on the lake taxi'n my wife and kids around than it does in a staging lane.