HI SPEED LEAN OUT--DO I NEED ONE?

[dusterdave173]

ok...new car 355 SBC, enderle pump, Hilborn stack on alky--everything is running great! Car starts easy, idles as good as any stack, runs same et almost every pass--running mid 5's in the 1/8th All Good!! I am not running a high speed lean out--Should I run one--do I need one?? How much will it help?? I like leaving well enough alone but...don't want to leave any big gain on the table--run 1/4 pretty rare--mostly 1/8th
Car runs cool as a cuke--can even drive it back if i don't play around--so i am guessing it is on the fat side
Just knocking some of the plating off NGK plugs around the ends--not up on the threads any
what to do? how to go about setting it and checking it--dialing it in ??
THANKS!!

[Spud Miller]

 Give this a read and see what you think...

 http://www.fuelinjectionent.com/highspeedheroics.php

 Spud

[afuelcoupe]

short answer no you dont need one and would be better off without it.....

[slingshot383]

Frank would say no, but that you would have a driver operated lean-out for that top end push to take the stripe.  If you are running a combination where you are launching at 6500 rpm or more, you would already be on the Hi-speed in most cases.

[wideopen231]

With most setups its not really needed.  Leaving around 6000 and shifting in mid 7000's your system will be  in narrow pressure range.It would be open full time so basically just same as basic system. A manual can be effective for little extra on topend,but only if system is little rich to start.Plus its not going to make a big jump like say a nitrous system would.

I have one designed into my system ,but its for building heat before run. Also have richening effect for cooling it and one for enrichment for nitrous setup at later date.

[fuel749]

The best answer is.....It depends

If you've ever dyno'd an engine with and without the hi speed, you'd be impressed with what you can get. May not apply to all combinations, but you might be surprised. Very easy to figure out the hi speed on the engine dyno.

[George]

I found the dyno to be an interesting way to break in an engine. I never found the dyno results on the track. I was told by a few racers the dyno will load the motor harder than the track. I believe if I could spend days playing on the dyno there might be a gain in tuning knowledge. Just my 2 cts.

[wideopen231]

Worlds best and most accurate dyno is 660 or 1320 feet long. I have had guys that dynoed motor picked up power and slowed down on track. Maybe the load. I do agree it can teach you few things,just not to live or die by.

 I have always just made change(1 at a time) and recorded effect it had on track  of coarse conditions come into play. With high speed its easy to A-B-A test.

[dreracecar]

In head to head competition, I have never seen a dyno win a drag race yet

[fuel749]

The dyno is just like the computer....the information it gives you is up to the user to figure out if the info is good or bad and how to use it. Higher horsepower doesn't always equal higher performance. And making dyno pulls isn't just about getting the highest number, it's about gaining information. Sometimes it's different info than can be learned on the track that you can combine with your on track info to be a better competitor in your class.

As far as a hi speed is concerned, I'll stand by my original answer because it depends on to many variables.

[masracingtd1167]

You guy's are right ! I have never seen a dyno win a race but the ones with the most horse power usually do ! We dyno my friends comp motors at the same shop every time so we know if one is better than another . We can also try different things like valve lash and cam timing and know right away if it is better or worse . Just my 2 cents !

[Curly1]

I have a High Speed lean out on my motor is a help. But it is an Enderle hat and it may be different than yours and not much help on some. On the difference between dyno and track there are a few things different and you have to compensate for them.  What I did was set up my injection on the dyno and I used the O2 sensors once I got the best performance on the dyno. Now when you get to the track you have forced air into the hat and it will need a little more fuel which will give you better performance. But you are still shooting for same numbers on the O2 sensors.

Point is the dyno is a great tool to help you get the best ET but remember the goal is still ET and not dyno numbers. You can learn things in one day on the dyno that may take you months at the track.