New Best

LaserSVT said:
Since its about 1/3 of a second and corrects itself right away I wonder if its because of the new port volume and velocity since the car now uses both intake valves at all engine speeds instead of just above 3200. Since the fuel tables take into account the port and plenum size for the targeted A/F you may have to adjust the specified plenum size in the tune.

Sorry thinking out loud. I would imagine you know that and have adjusted accordingly.

On a side note have you data logged the knock sensors to see if they are comanding and retard during that lean spike?
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From a bit (:eek:) of reading I've been doing in the past few hours, my guess is that I may have caused it by changing the manifold volume to 10 (stock Cobra value) from 6.875 (stock Gen 2 Mark VIII), without also changing the transient fuel tables. Theoretically, that would cause not only the tip-in lean spike, but also the rich spikes during the shifts.

I'll find out tomorrow. ;)

Think out loud all you want, I'm looking for any help I can get. ;)

Nope, I haven't logged anything other than what I posted yet.
 
Changing the Manifold Volume back to the stock value got rid of the lean spike.

1st pic is with Manifold Volume @ 10
2nd pic is with Manifold Volume @ 6.875

Next is lowering the A/F ratio following the initial hit (red circle).

LM206161100.jpg


LM206161102.jpg
 
Working on the tune a bit produced some good results tonight @ Atco.

:D:):D:):D

The DA tonight was 1059 ft. According to Drag Times, that corrects to 13.444 @ 103.478!

Does anyone have a quicker N/A Gen 2 with stock internals? ;)

p.s. again I got some yo-yo in the other lane..... :p

20110616 Time Slip.jpg
 
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Good run! Its always nice to go faster everytime to track. How many nights does Atco run? NED is only weds and fridays for street night.
 
Right on the Mark said:
Good run! Its always nice to go faster everytime to track. How many nights does Atco run? NED is only weds and fridays for street night.
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Thanks!

Tuesdays and Fridays are street nights, with Thursday as a rain date for Tuesday, which is what happened this week.
 
I think both our cars show that one of the best places to look for ET is in the whisper quiet exh choke in these cars.
 
Great run, nice job!! Drag racing 2-days in a row at 2-different tracks, even better!!

Ken
 
14.6@97MPH said:
Great run, nice job!! Drag racing 2-days in a row at 2-different tracks, even better!!

Ken
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You were @ Englishtown, you know how pissed I was at the lean spike issue in the tune, I had to solve the problem.
 
Good run! Was your track slippery as balls? Went last fri to watch and NED was a skating rink. Peeps where spinning whole track.
 
Very nice.

My best to date is 9.3 @ 78 slicks, spares on the front, pass seat removed. Bone stock but gears

I'm gonna see if I can hit an 8.9x with my tune once I get back to the strip this weekend
 
slowmkviii said:
Very nice
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majorownage said:
Very nice.

My best to date is 9.3 @ 78 slicks, spares on the front, pass seat removed. Bone stock but gears

I'm gonna see if I can hit an 8.9x with my tune once I get back to the strip this weekend
Click to expand...

ford nut said:
Great 60.

Nice R/T
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ONEBADMK8 said:
Congrats man!! Thats so cool my best ever was a 13.44 @102.993 with a 1.81 short time.
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Thanks all! :)

I ran with only the spare and jack removed, 245/45-17's up front, around 3,980 race weight.

MT 275/40-17 DR's @ 25 psi.

In addition to the run above, I ran off a string of 13.5's launching @ 1,500 RPM, last pass I launched @ 2K.

13.557
13.569
13.521
13.568
13.556
 
majorownage said:
How much timing? afr?
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Well, I'm commanding a total of 29 degrees above 4,500 RPM and I've got the knock sensors set up to add as much as 3 degrees, but (and I'm ashamed to admit it :() I haven't data logged the timing at the track to see what's actually occurring. When I installed the IMRC deletes and the Cobra intake, I grabbed the timing table from my '98 Cobra tune (which has been completely logged and worked out over several years of racing), and it seemed to work fine, so I haven't gotten around to taking a closer look at it.

A/F here:

http://www.lincolnvscadillac.com/showpost.php?p=831280&postcount=9
 
I've been talking to alot of the n/a b cobra guys, and they say that the stock ford knock sensors give false readings ALL the time.

With IMRC deletes a guy on another forum is running 32* all the way up to 4k, then 30* to 7k. His cobra runs 11.7s @ 115 so I think I could trust his judgement.

I was using his recommendation, but I could clearly hear a bit a knock after she shifted into second, so right now i'm using 30* 3k to to redline.

Really stoked about finding how much mph I gained.
 
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