Steve-Need Your Low Gear Fueling Thots

[Scoobum]

Okay...here's the deal. My thermometer/barometer at the track last nite was showing 74 degrees and 68% humidity. I pulled the full 20% low gear fuel from Erics chip...and the low gear fueling checked in at 791. I'm expecting 55 degrees and humidity in the low 50's in October. Will mother nature and 8 more pounds of boost push the low gear 02's into the 750's where I need them...or do I need to have Eric send me the same chip...but with 10 to 15 percent less low gear fuel. The car went 7.2 at 98 on 20 lbs with an easy 1.71 launch last nite. The only other thing I did was add 2 degrees of low gear timing. High gear 02's came in at 790.

Food for thot. I made my run at 7:30pm last nite. When I packed up my car/truck/trailer already had dew on them.

Track runs from east to west...with a steady 10 kilometer an hour wind from the SW last nite when I made my run.

[Steve Wood]

Being that nb o2's are not the slightest bit linear, I hesitate to say.

You will have a lot more air with colder temps and lower humidity which says the car will be a lot leaner.  I think I would probably add some fuel for the first run, myself.  This is one of those cases where experience and a log book for the local area would be useful.   

You need a test and tune run or two in similar conditions.

I am no help in this case.  I just don't have a feel for it.

[Scoobum]

There's 5 more race dates between now and the finale in October. Let's see what happens.

[nocooler]

Brad - I don't have any notes. I just would do some street passes, back to back and saw what the car liked for a few days before running at the track. But I just liked messing with the car and something always was tweaked during or after a ride. 

[Scoobum]

I like to see a complete run on PL to make my adjustments. As I've gotten older I've gotten incredibly patient and methodical with everything to do with the car...and there's plenty of track time left. One month ago it was 7.9...last week it was 7.4...last nite it was 7.2. I'll keep chipping away at it as the weather cools.

[Tim Hensley]

your not just chipping away at it.Your using a big hammer
I like looking at numbers
from 7.9 to7.2 in the 1/8 is a good job,but 98 mph with a 1.7 60ft that car is moving on the top.
I see why you are trying to get low gear fuel out, is it to lower the 60ft?That 98 =1.5 60ft and 6.94 ET
Im watching this to see what happens next.
Im no tuner at all ,but I think I would add timing

[Tim Hensley]

Sorry Im not Steve and cant get my TR to run that good,But Im trying

[motorhead]

Brad, you should look to get/put more timing or air into it at lower speeds it would achieve the same/similar effect as leaning it out vai fuel.

[Scoobum]

Brad, you should look to get/put more timing or air into it at lower speeds it would achieve the same/similar effect as leaning it out vai fuel.

Mike, I agree. On a practice nite...like Friday I can get away with murder. On a race day...anything quicker than 7.3 and I get tossed for no roll bar. I ran that 6.7  last year in morning practice on a race day...and was told my day was over.

[Scoobum]

Tim brings up a good point...low gear tuning. Let's look at the 3 runs.

7.9
Boost 16 PSI
Low Gear 02's 870
High Gear 02's 830
High Gear Timing 24
Low Gear Timing 26
60 Foot 2.2
Air Quality-Hot And Humid

7.4
Boost 20 PSI
Low Gear 02's 820
High Gear 02's 820
High Gear Timing 24
Low Gear Timing 26
60 Foot 1.9x
Air Quality-Hot And Slightly Less Humid

7.2
Boost 20 PSI
Low Gear 02's 790
High Gear 02's 770
High Gear Timing 24
Low Gear Timing 28
Air Quality Same As 7.4 Run
60 Foot 1.7x

[Scoobum]

Tim, I could add 2 more degrees of low gear timing and pull a little more high gear fuel...and I could whittle that down to 7.0. Steve and I have bigger plans. We're gonna wait till our Thanksgiving weekend up here...when the temperature is in the low 50's and humidity in the low 50's. We're gonna throw a whack of high gear fuel at it...turn the boost to 28 lbs...add 6 degrees of low gear timing to it above Erics default...boos t it to the moon...and then hang on for dear life. I managed the time in my sig last year doing the same thing at 25 PSI...but ran out of injector. This year...there's 80's in it instead of 60's. It's gonna be checkers or wreckers. Stay tuned!

[Scoobum]

Tim...you made another good point...about the car turning a fast MPH. It wasn't always that way...and I learned a lesson. Bigger...ain't always better. I had a 70 P trim with a Garrett .63 exhaust housing. The car went 12.2 at 112 at 22 PSI. The CEA 6262 had just come out...and Patrick Rubio who was still working at Precision at the time had put a post up on the other board of the new turbos and the stall requirements. I was running a 16930 which is around 3000 at zero boost...and the 6262 JB matched it. I called Patrick...and he instantly told me I over turbo'd the engine with the 70. I bolted on the 6262...set the boost at 22 PSI...and the car immediately went 11.5 at 120...with no other changes.

[motorhead]

Timing and boost are high and low, respectively, based upon my experience.  You definitely need to add more air to go faster at this point.  But, damn can C16 take some timing.

[Tim Hensley]

I have a few ?
is this with race gas? I see no reference to fuel type
Dose this car hook good?
full weight car?
Is this your stock block 109?If so I see why it is faster with the 6262
What fuel pump  is feeding your 80s today
By the numbers you can get it down the track and adding timing did help the 60, with helps the ETs
can you post up your time slip?
You will get to a point that timing and fuel will peak,these are little air pumps and as  weather gets colder it will add power you just need it at the light,thats the 64thousand dollar ?

[nocooler]

Brad - don't forget to focus on the slips. Don't know if you have 330' markers - This is where you should see if it's helping as well.


The only way you can compare air is by density altitude.


The low gear timing @ 28 is what I used to run and then 24-25 thru the back end. And as I leaned it out it'd change exhaust tone


I miss that whistle and how the car felt with the converter locked at wot, all while sitting on a couch.