Throttle Responce

[Mr. OAM]

Just put a vacuum gauge on your intake manifold and adjust the idle mixture screws on the carb until you get maximum vacuum.........


Ah, you don't have a carb though. :dancing6: Food for thought, on a serious side though, is there an equivalent with an EFI throttlebody? Perhaps tuning to gain the most engine vacuum at idle? This gives my wife's carbed 331 amazing throttle response off the line, along with the excellent carb and power to weight ratio.


Steve

Even if we did have a Carb, our 4.6's don't produce enough vacuum, so that would most likely not make a difference.

Just how much vacuum do they produce? There is vacuum because you've got the piston drawing in air through the throttlebody. Whatever that amount of vacuum is, the throttle response would be best when the mixture at idle is optimized for maximum vacuum, no matter how low. 3-4 inches of vacuum with ,make a difference. I am sure the engines still produce at least 10 inches of vacuum at idle?

A possible clash that could come about is the emissions at that mixture. The computer may not like it, I don't know.


Steve

 

[Jrgunn5150]

You don't (or I don't rather) actually monitor vacuum at idle, I monitor the MAP sensor :thumb: But yes, it's somewhere around 10-12 inches at idle. Low vacuum is the reason they use hydroboost brakes on these engines though.

I did it when I tuned my engine, it can all be done in the ECU, while datalogging the ecu, and even 1bar makes a noticeable difference

 

[justinschmidt1]

i dropped .5 seconds with my prostars.

i believe it...

details?

did you go from street tires to DRs or slicks?

any differance in 60 foot time?

trap speed?

were you running prostars all the way around?

im curious...

Went from stock GT wheels with NT 555s on them.

60' is the same, i dont hvave the power to push ET streets(bought them for the future), BUt plan on 1.70 60' with a stock suspenison except drag springs.

and 3.5 x 15s up front, and 10x15s out back.

sweet...drag racing is fun...but I dont feel like spending any ore money...especially on a 1,000 dollar set of rims that I would use twice a year haha.