Crossfire vs. Crossfire with 55k engine - YouTube

there is a one second between us

me,,,,,,,,,,,,,,,rt=359,,60'=1.69,,1/8=7.2,,1/8 mph=98,,,ET=11.23 @ 123.38
big kid jim,,,,,rt=430,,60'=1.80,,1/8=7.9,,1/8 mph=88,,,ET=12.36 @ 111.23

I have to give big kid lots of kudos,, this was on street tires and this was his 7 or 8 run ever on a drag strip.,, 4 at a 1/8 mile track on Friday and then here at PBIR 1/4 mile track he ran 4 or 5 more. great job jim. come back to South Florida our track is open year around jim

 

Stock Crossfire running 12.3? I don't think so...... Great video Jim! I'll be on vacation the week of March 12th, so maybe a visit to PBIR is in order. I will be staying at my in-laws in Port St. Lucie.

 

big kid is far from stock. more like he's the needswings catalog and then some! jim your run @ 111 leads me to believe your running lean at the top. with the 12.3 you should be @ the 114 to 116 range. check your dataloggs please. my guess is the car is losing power at the top of 3 with the ecu pulling timing. if you still have the same tune you had when we met in atl its way past time for a retune!

 

I think big kid has the old tune ,, when we all ran 12.1 to 12.3 this is why he could go no faster than 12.3 ,and don't forget this is his first week ever at the track. jim

 

That 111mph has lean written all over it. I was running 12.3 on street tires with a 111 trap when I was seeing 14-15 A/F. After adding the fuel pump my trap increased by 5-6 MPH. New tune, old tune, whatever tune, sounds lean to me. Isn't the stock trap speed on the SRT6 around 109?

 

Indeed.

Definitely time to get a re-tune... with the mods BigKid has, he should be tickling 11's at 117-119 providing there was enough fuel.

 

Thanks for the heads up on the lean issue guys, I will plug in the old laptop and record a run or two.

Thanks to Jim for hosting me and coaching me. And for introducing me to yet another way I can spend money on my car. Randy and all the other racers I met were great. Randy thanks for the golf. That was fun and profitable.LOL

I was at the shop getting an oil change this morning and the guys there were explaining that my beautiful 20" rear wheels had changed the gearing on my car from 3.07 to something like 2.75. Chris said that would affect the launch, 60' and 1/8 mile times fairly drastically. ?

So I will get a couplel of datalogs off to Rob soon.

 

Absolutely.

Can you tell me what your rear tire specs are? A thinner sidewall would certainly made the OD smaller, yielding an effectively lower gear (or in your case, closer to stock).

Problem is, the thinner the sidewall, the less sidewall flex you have and therefore the easier it is to break traction for a launch. The 20's are killing you, but they sure do look pretty. Even the factory 19's on our cars are torque-stealing boat anchors. There's a reason Les is running 18's all-around...

 

John the rears are pilot super sport 285 30 ZR 20.

What time difference would you speculate this set up would add vrs the 17" dr's ?

 

Your setup is nearly an inch taller than OEM... And, quite a bit heavier to boot.

Ignore the rim width/backspacing, as I just put something in there to fill the void...

This gives you a visual reference of how much taller the wheels/tires are. To alleviate this with a 20" wheel, you'd have to drop to a 25-series tire... not worth the risk of bent rims and zero cushion IMO...

 

I'm thinking your 111 trap speed could be a rich condition instead of running lean. Dumping too much fuel on top would hurt it for sure. I bet the a/f is probably at 11.0-11.5 at red line.

 

I for one would say 11.5 is perfection at redline on a F/I engine. Rich, that's more like 10's.

 

the best afr at wot at the top of 2nd gear and 3rd gear would be 12.1 to 12.3

the 10's is rich,,, the high 11's is ok infact 11.7 to 11.9 would work just fine ,,, 13's your in trouble again this is at wot. jim

 

My car is around 12.6 A/F.

 

Neil, that is why your car is so fast, you are a little high, if i were you i would try to lower that to 12.0 to 12.3 ,, add fuel pressure if you can maybe add some race fuel and see what you have .. with my v8 I am running 10.9 to 11.6 sometimes 11.8 I would like to see 11.9 12.1 at 4000 to 6000 RPM in all three gears. ,,talked to Rudy and we are going to remove some fuel in 2 and 3rd, and around 5500 rpm.

 

Unless Neil installed a wideband since I last talked to him, that AFR was from the tailpipe on a dyno. They read a little leaner. The last time I got re-tuned, I datalogged through my wideband and also had the tailpipie sniffer. The tailpipe reading was about 0.5 leaner than my wideband reading.

So, I think he is OK

 

with that info i agree,,, so now Chuck join Neil and come on down ,late Feb or march very busy next three weeks jim

google PBIR to see whats going on.

 

Exactly. I trust our forged internals.

 

April 27 is a midnight madness maybe you guys can come down.

went last night one run 11.27 and 4 runs 11,30 to 11.36

 

Nice! I would like you to do 10's what speed do you get with street tires?