Throttle opening

[wideopen231]

Spud,

  Appr. what would butterfly gap be for 5000 rpm.Injected motor using bird catcher.Understand is not exact number.Must need to be in center of ballpark for peice I am making.iF know a range that would be great.

[Spud Miller]

 Sorry...I have no idea. Too many variables! Load on the motor, leakdown percentage, main pill, secondary bypass, etc. make guessing close pretty impossible. Trial and error I'm afraid.

 Spud

[ricardo1967]

Way too many variables... just ignition timing itself would throw that off significantly.

[dreracecar]

Start high and back down, too little and it wont start

[masracingtd1167]

Chris With that hemi I would think full throttle it might make 5000 . I just couldn,t resist !!!

[wideopen231]

Yea Bill but the TQ  would flip a SBC over backwards and into the ground.When you have tq who needs RPM? Could resist but did not want to.      Use to go 10,000 but had extra lung pushing 45# boost,had to help some.

Varibles.MSD mag 20 at 36 to 38* 125 pill 6.65 gpm pump system pressure right at 110(according to Spuds calculator).Now as for load during stagging can not say.Converter is 6600 stall on brake. Trying to work out a SLE thats electronic only no co2 to emilanate bottle,lines and few other parts.Less lieces less to go wrong

[ricardo1967]

Chris With that hemi I would think full throttle it might make 5000 . I just couldn,t resist !!!

Could it reach that far w/o nitro, NOS or a huffer?? (sorry Chris  )

[wideopen231]

I kniow Ricardo but appoligee is in order.Again did want to resist.

[wideopen231]

lets rework question.

If you have positioner that makes throttle hit exact same spot every time it should be almost dead on same rpm(no other changes to system jet or tuneup) .True or false? If expect a rpm change I would think very minor

[ricardo1967]

True. But throttle controls engine torque, not speed. The achieved engine speed is the result of the torque produced for a given throttle opening minus the load to the engine. Quick example is how for the same throttle opening the engine speed changes (drops) when an automatic transmission is shifted from Neutral to Drive.

To achieve what you want, I’d probably start with a ¼” opening and start opening up gradually to achieve the 5000 rpm target. Just be careful because, being a mechanical fuel injection, air/fuel ratio might be off at that part throttle position (concerned with engine overheating).

Good luck Chris.

[wideopen231]

only going to be at rpm 1.25 to 1.3 seconds for tree count down from top to bottom bulb. Heat not much of issue. at 1.--- throttle will be WIDEOPEN for  run. Its just a SLE but working on full elctric piece want to elimanate need for co2 bottle and lines. Just need a starting point and allow for some adjustment.

[masracingtd1167]

Chris why not just leave off of a chip ?

[wideopen231]

With injection and having BV fullopen for 1.5 puts a lot of fuel to motor  killing AFR. Plus with SLE I can program box to open slightly before hit if need and use a chip that is dead on rpm I want at hit w/o going overly rich, has to be more consistent.

Bill remember the crap I heard over on DRR about how stupid building a fed for brackets was when I started this.Don't look back at it reminds you how freaking long this has taken me,I know I hate seeing dates on it. Again I shouild have choosen wealth over great looks. LYAO right? Got to use everything I can to prove them all wrong.Nothing like a challenge to get firedup.

[masracingtd1167]

Chris I have tried mine both ways with a throttle controller and with a chip and really saw no difference  . I leave full throttle with a chip and have had no issues . Another option is a converter helper . It is an electric solenoid that bleeds off fuel when the trans brake is on . I know that Rons makes one and I think Spud makes one also . Don't pay too much attention to those guy's on Bracket Talk . There are a few of them that are pretty smart but for the most part they are pretty clueless . It's good entertainment ! How is the car coming along ? If you do things like everyone else you can only be like everyone else ! If you want to be better than everyone else you have to think outside the box !

[wideopen231]

HAve thought about the electronic leanout.  It is also a possiblity if electric control piece does not work. I have everything to set it up to do the chip part and would only need the valve. I know it would save some time and get car done quicker time wise.Bad thing time is not holdup.Like most know money is normally hold up on builds. 250 for valve versus 0 for electronic sle(if it works),well may have to buy shorter cable.

  As for car.I need cpl pieces to be fire in the hole ready.Starter(custom mounting block) ,battery 16 volt (after starters mounted),Zoomies (sold last set DA),converter is on the way and valve body kit on the way.I shelved the billet deal for while,would like to do billet with high/low setup and need to study some on it. Hopefully upsetting neighbors in cpl months.