Why do sprint cars use mechanical fuel injection?

[lazyifoto]

Sprint cars don't have a battery so fuel injection "I believe " has to be mechanical. ...also again I believe that alot of sprint car motors plumb the injectors directly into the head and only receive air through the injector tubes.

[Stede Bonnet]

Not Necessarily ...

Sprint cars don't have a battery so fuel injection "I believe " has to be mechanical. ...also again I believe that alot of sprint car motors plumb the injectors directly into the head and only receive air through the injector tubes.

Most sprint cars don't have batteries, but some nowadays, do. The Joe Hunt Magneto Wingless series mandates a starter and a battery on every car, the battery is usually under the seat. The injectors are located in the manifold on most every sprint that utilizes MFI, no tuned port. According to the rules of most series that I've read they don't list what type of induction you must use, only alcohol, at least not WAR or BOSS. Now the Elite series guys in Texas stipulate MFI and a RS305.

[CIRF]

Most sprint cars don't have batteries, but some nowadays, do. The Joe Hunt Magneto Wingless series mandates a starter and a battery on every car, the battery is usually under the seat. The injectors are located in the manifold on most every sprint that utilizes MFI, no tuned port. According to the rules of most series that I've read they don't list what type of induction you must use, only alcohol, at least not WAR or BOSS. Now the Elite series guys in Texas stipulate MFI and a RS305.

Since WAR has merged with POWRi I've done some investigating to become familiar with the rules given that WAR will be racing at several tracks near to us during the 2017 season. WAR actually has very few rules and it seems they are wide open as to engine guidelines. The rules state that there are no engine rules. That's one reason I kinda' like the WAR series. It's truly a grass roots outfit, for sure.

This Elite Series in Texas seems to be gaining some popularity. A buddy of mine who lives in Oklahoma has attended several of their shows and really likes them.

The URSS Racesaver 305 sprints can run carbs or MFI. They have been the support series at The Belleville Midget Nationals the past couple of years and they do a good job. These cars are interesting in that you can tell exactly who's running MFI and who's running carbs.

[Stede Bonnet]

...The URSS Racesaver 305 sprints can run carbs or MFI. They have been the support series at The Belleville Midget Nationals the past couple of years and they do a good job. These cars are interesting in that you can tell exactly who's running MFI and who's running carbs...

Interesting, what differences do you notice between 4 barrel and MFI?

[CIRF]

Interesting, what differences do you notice between 4 barrel and MFI?

It's the sound of the engine that is the difference. The cars with carburetors sound much like a late model with the distinctive cackle of the exhaust note during deceleration. The carburetor engines also have a distinctive sound upon acceleration, as well. They have a deeper sound unlike the MFI engines which have a bit more of whine and have a higher pitched sound.

It's easy to tell the difference.

[Stede Bonnet]

It's the sound of the engine that is the difference. The cars with carburetors sound much like a late model with the distinctive cackle of the exhaust note during deceleration. The carburetor engines also have a distinctive sound upon acceleration, as well. They have a deeper sound unlike the MFI engines which have a bit more of whine and have a higher pitched sound.

It's easy to tell the difference.

Hey CIRF,
This is off topic, but I saw this morning on IOW that the Lucas Oil Southern States Midget D2 cars are going to be in Georgia in february!!! I can't wait, never seen a midget race in person and its only like 2 hours from my house.

[CIRF]

Hey CIRF,
This is off topic, but I saw this morning on IOW that the Lucas Oil Southern States Midget D2 cars are going to be in Georgia in february!!! I can't wait, never seen a midget race in person and its only like 2 hours from my house.

Stede, although the division II midgets provide very good and exciting racing they aren't the full on USAC, POWRi or ARDC midgets. Be advised that the D II midgets look nearly identical to the full on midgets there is a lot of horsepower difference. The D II midgets are restricted to using OEM 4 cylinder engines of several different manufacturers.

They are:

GM Ecotec 2.4L (LE5), or 2.2L (L61)
Honda 2.4 L (K24A1)
Chrysler World Engine 2.4L
Toyota 2.4L (2AZ-FE)
Ford/Mazda Duratec 2.3L (23 I-4/L3)
GM Quad 4 2.3L and 2.4L
Ford 2.0L Focus/Scream Pre-2004 (see notes)

They can't be massaged very much and must use OEM blocks, heads, camshaft's and crankshaft's. No porting of the heads is allowed. The lower end can be balanced but no lightened or knife edged crankshaft's are allowed. They can choose to run either MFI or EFI either with plenum or individual runner intake systems. They are basically powered by an OEM engine and a clutching system with starter is optional.

They put on a very good show but are noticeably slower than the full on USAC/POWRi/ARDC midgets. But, the engines cost way, way less than the full on TRD's and Esslinger's.

This is a very good purse and I would highly recommend attending the Georgia show. I don't think you'll be disappointed. Since you haven't seen the midgets in person you won't have the full on midgets as a frame of reference thus you'll probably enjoy it even more. The difference between the full on midgets and the D II's is very much akin to the difference between a super dirt late model and a crate late model. From the outside they look identical but what's under sheet metal is a whole other beast.

Go, and have a great time! This might be the biggest purse these guys have ever raced for and there should be a ton of cars!! Let us know how you liked the show.

[Stede Bonnet]

Stede, although the division II midgets provide very good and exciting racing they aren't the full on USAC, POWRi or ARDC midgets. Be advised that the D II midgets look nearly identical to the full on midgets there is a lot of horsepower difference. The D II midgets are restricted to using OEM 4 cylinder engines of several different manufacturers.

They are:

GM Ecotec 2.4L (LE5), or 2.2L (L61)
Honda 2.4 L (K24A1)
Chrysler World Engine 2.4L
Toyota 2.4L (2AZ-FE)
Ford/Mazda Duratec 2.3L (23 I-4/L3)
GM Quad 4 2.3L and 2.4L
Ford 2.0L Focus/Scream Pre-2004 (see notes)

They can't be massaged very much and must use OEM blocks, heads, camshaft's and crankshaft's. No porting of the heads is allowed. The lower end can be balanced but no lightened or knife edged crankshaft's are allowed. They can choose to run either MFI or EFI either with plenum or individual runner intake systems. They are basically powered by an OEM engine and a clutching system with starter is optional.

They put on a very good show but are noticeably slower than the full on USAC/POWRi/ARDC midgets. But, the engines cost way, way less than the full on TRD's and Esslinger's.

This is a very good purse and I would highly recommend attending the Georgia show. I don't think you'll be disappointed. Since you haven't seen the midgets in person you won't have the full on midgets as a frame of reference thus you'll probably enjoy it even more. The difference between the full on midgets and the D II's is very much akin to the difference between a super dirt late model and a crate late model. From the outside they look identical but what's under sheet metal is a whole other beast.

Go, and have a great time! This might be the biggest purse these guys have ever raced for and there should be a ton of cars!! Let us know how you liked the show.

Thanks for the info. I saw what you mean by cost, I think an SR-11 from Stanton is like $36K !!! Ouch. How long have D2 midgets been around?

[CIRF]

Thanks for the info. I saw what you mean by cost, I think an SR-11 from Stanton is like $36K !!! Ouch. How long have D2 midgets been around?

I'm not positive Stede, but I believe this will be the 3rd season for the POWRi D II. I know it hasn't been more that 4 seasons.