Can an injector be too big?

Im still running a small engine(451) on a 950 HP alcohol on a bracket/QR dragster. I want to go to injection to gain consistency and possibly go a little faster in time. I know I can use too much carb for the engine combination. In an unblown(so far) system is there any advantage to a bug, bird, buzzard, bug and ugly shotgun, etc? As I grow up and go to a faster combination whether more CID or forced induction, is it necessary to use a bigger injector each time I upgrade or can I use something big right from the gitgo? Im wondering about performance as well as part throttle characteristics in the pits and staging lanes.

 

I don't think you can be too big for power purposes (WFO), but...
If throttle control is a concern,,, bigger butterflys and older hats (bug, bird etc) will give your motor more "throttle"/butterfly shaft angle.

Butterflys buried deeper into the throttle bore give smoother more controlled action. And bugs and birds have a step in the throttle bore which create a jump in opening area at about 25° of shaft rotation.

I'm surprised in drag racing this is a concern.

 

Im mostly concerned about wild rpm changes when doing simple things like rolling into the water or driving in the pits. I dont want to crack the throttle and have the engine suddenly revving to 5 or 6 grand.

I see people getting along good with low power engines (under 1000) using a bird on a tunnel ram or manifold injectors like Hilborns. I like the idea of an upright such as Gerodot, or Hilborn 4 port or 2 Rons toilet type. At this time I couldnt approach the CFM capabilities of any of those. Upgrading to a 572 blown app could then strain the smaller injectors.

Should I buy more injector capacity than I need and only buy once, or will I be unhappy with the part throttle characteristics? I now stage at a fast idle after the prestage is on. If my throttle plates are 5 inch as opposed to 3.75 would I suddenly be staging on the chip?

Sorry if Im not getting my point across.

 

when we ran our old car injected on alky we had a pretty neat deal. we had Gerardot build us a sheet metal intake and used a bird catcher on top......it was absolutely trouble free!!! you could idle it where ever you wanted, and the throttle control was great. call Don and talk to him, tell him what you want to do.....it only costs a phone call.
Darren Russell
www.gerardot.com

 

scoop

having a big scoop opening then restricting it down to your throttle blade should increase the velocity of the air and should make more power

 

Back when i ran an injected only car i used a hilborn stack set up and I loved it .
Personally ,I think stack injection "Hilborn,Crower,Kinsler" is a better way to go, they were designed for N/A applications. They arent a reworked blown setup. They work pretty well for the A/ND guys too

 

I agree with the stack idea but Id like to go blown in the future which would require a new setup. Id like to avoid buying new each time if possible. If Im shooting up the wrong tree Id like to know that too.

By the way, I run a B block Dodge. Not too many stacks floating around for those.

 

I dont think there is such a thing as too big, my setup is close just bigger, im running run a 572 mopar wedge with Crowers old 8 port blower hat, they are 2.812 bores and it ran great. The throttle responce is pretty fast but I think that all depends on your motor and tune up.

I built a manifold to keep it an individul runner injection, but I've heard good things about the tunnel ram idea too. I too am switching to a blower setup this year and im keeping my Crower hat, it just looks too damn good not to.

Back when I ran a 440, I switched from a carberated gas to a tiny old 2 1/16 bore hilborn on alcohol, it ran wonderfully, I picked up a half second, and ran 9.90s in a 3000 lb car, 12 to 1 comp, and those cheap edelbrock performer heads. So theres nothing wrong with the smaller injection either.

 

I will have to agree with Will, talk to an injection expert, I've always had great luck with Kinsler, they have good parts and good advise.

 

you could call automan too, and talk to him for a few hours.
he would tell you the difference between the scoop that wood chip posted and a real ottow injector.
he probably would school you more in barrel valves and 9/32" openings....
for returns you know...
sorry chip....lol

 

OK, so I can have to many sq in opening. I follow that and will plan accordingly.

I still am wondering tho lets just say we have 80 sq in total opening, will my throttle response be any better with one 80 in butterfly(barndoor), 2 40 inch butterflies(shotgun) or 8 10sq in butterflies(stacks)? Is it harder to tune a large throttle than a small one? Not knowing actual measurements off hand, if you open the throttle 10* on a shotgun dont you pass more air than say 10* on a small stack?

Im sorry for making this a long drawn out question. I think its my age and prescription drugs ganging up on me.

One other little thing, Moparious Maximus, where at in Iowa are you? Id like to get a look at your system. I think Ive seen your car but not positive. And you are SO right, there aint nothin that beats the look of an old Crower!

 

..............................
Dave Koehler
http://www.koehlerinjection.com

 

Thanks Dave!

I wanted to use a TR just because I can find more of those. Im partial to the "look" of a Hilborn 4 port or the Crower but again there aint so many Crowers around for a reasonable price. I like the look of stacks to, but they "belong" on FEDs.

Thanks to all.

 

FlyingPig I am close to Muscatine around Davenport, I'd be glad to trade stories with you or ideas or just plain old B.S. Im not saying I know everything, I know I dont, there are way smarter people on here than me, but Im always willing to help out if I can.

As to opening size in drag racing you are mostly on or off as far as butterflies are concerned. Lets see, green light ON>>>>> dont turn off until 1/4 mile is done.

As far as the stack injection, you do have to watch the quality of the manifold, or you will have problems getting all of the plates flowing the same at an idle. We fight it all the time on our small chevy FED, doesnt really bother performace, it just plain sounds bad at an idle. If your going to run a tunnel ram setup this makes no difference.

I stumbled on my crower injector on ebay, im not saying it was cheap, but its like new and runs great.

 

I have to agree with will Enderle will help you get the correct application for your setup. Very good group of guys with a world of knowledge. Definetly worth at least a phone call to them.

 

Hey the picture posted by Woodchip is Automan's injector and scoop on Gary Andersons A/FD. Bob has built a bigger injector than this version. I know NHRA has gotten tougher on injector size.

 

too big?

can you go too big on a blower injector.
I just got a B&U 5.567 plates on a 540 BBC with a 8-71 superman.
What are the difference's between a smaller on vs. a larger one.

Thanks