New Track Times

[Venom351R]

Today I was finally able to go to the track today w/ the Cobra running 100%. I have made some previous trips but was chasing issues all summer long but today made up for all of it as I got a new best 1/4 time and 60' time

I wanted to do more runs ( I had 3 good ones) but the engine torqued so much on the next launch that it broke the ATI sensor in half, must have hit the strut tower ( I have a C&L inlet tube) and it threw a check engine light after that so that was the end of my day b/c the car was not running the same after that. Here are the results.


RT... 394

60'... 1.708

330... 5.179

1/8.... 8.047 (almost got my 7's in the 1/8th)

MPH... 87.42

1000... 10.583

1/4...... 12.715

MPH.......106.74


I was happy, the car has 12.5's in it. It was 76 degrees today with 78% humidity. This fall in the cool air I should be able to get some sub 12.5s

 

[revhead347]

What kind of tires were you running? I'm looking at one of my motor time slips from 2002, and I'm only a hair faster in the 1/8th with a 8.025/87.72mph. I had a 1.69 short time and a 12.503/109.87. So yeah, I would agree, you got a 12.5 in there somewhere. Not sure why you are coming out 3 mph slower at the end.

Kurt

 

[Venom351R]

Im running MT Drag Slicks. I was thinking my MPH should be a little higher. Think the TFSR is running out of steam at the top end? I also have AFR heads from back in 2000 so who knows how good they actually are.

 

[95Vert]

Do you have a vid of your pass? How much does your car weigh? MPH do seem low.

 

[Venom351R]

no video, I had it w/ me but no one I knew there to take it.

Car weighed in at 3,582 w/ me in it. Im 182.

 

[revhead347]

I don't think a video is going to help you that much. With a 1.7 short time, you're getting obviously getting out of the hole just fine. I run a Systemax 2 Intake which is even a longer runner than the Trick Flow, but I do have bigger heads. I thought I was losing a lot at the top end at 109 mph. Something is clearly running out of steam at the end of the track though at 106mph.

Kurt

 

[Venom351R]

I don't think a video is going to help you that much. With a 1.7 short time, you're getting obviously getting out of the hole just fine. I run a Systemax 2 Intake which is even a longer runner than the Trick Flow, but I do have bigger heads. I thought I was losing a lot at the top end at 109 mph. Something is clearly running out of steam at the end of the track though at 106mph.

Kurt

If I had to guess I would say it was my heads. I called up Trickflow today and they said a TF 205cc head is much better suited for my application. Also it was really hot w/ high humidity yesterday, temp of 72 w/ humidity at 78%

 

[Grn92LX]

Your 185s are fine. Your mph is way low for the power. I'd look into what rpm you're trapping. You probably need more gear. How high are you supposed to shift this combo? It will say an rpm range on the fti cam sheet.

 

[Venom351R]

The sheet says the power band is 2,400 - 6,200. I shift at about 6K or just over that b/c my tach is 200 RPM off, maybe Im just not winding it up high enough

 

[diponyou50]

nice man

and hey i think you should you go ahead and get yourself some new heads.

and ill pick up those afrs!

seriously.

pm

 

[Venom351R]

Sent

 

[Grn92LX]

You don't need new heads. Sounds like you need to rev it higher. And based off what the sheet is saying you definitely need more gear. You're probably crossing the traps in the 5200-5500 range where as you should be crossing around 6500. Looks like 4.30's are in your future.

I had that same problem with my old 92 LX with an 11:1 347. I had 373s in it and was only crossing the traps around 5500 with a pathetic 115 trap speed where I should have been crossing 6700ish . As recommended by Ed I swapped to 430s but never went back to the track. Car woulda went 118-120 with the swap.

 

[Pokageek]

Why are we complaining. That was a great run.

 

[Venom351R]

You don't need new heads. Sounds like you need to rev it higher. And based off what the sheet is saying you definitely need more gear. You're probably crossing the traps in the 5200-5500 range where as you should be crossing around 6500. Looks like 4.30's are in your future.

I had that same problem with my old 92 LX with an 11:1 347. I had 373s in it and was only crossing the traps around 5500 with a pathetic 115 trap speed where I should have been crossing 6700ish . As recommended by Ed I swapped to 430s but never went back to the track. Car woulda went 118-120 with the swap.

no way am I running 4.30's in this, I dont care if that was an issue or not. its at almost 3K on the interstate at 75-80MPH w/ 3.73's and going to the track is all highway for me....out of the question.

 

[Venom351R]

Why are we complaining. That was a great run.

I agree. I'll spend $1,900 on heads before I spend $150 on 4.30's

 

[95Vert]

TFS owns AFR. It has been beat to death at another forum that I can't seem to post here.

Keith, no one is complaining, but given the combo it SHOULD be faster. I was trapping 105mph with my POS untouched GT40 heads and a crappy cam. Something is definitely wrong. If he doesn't want to spend on gears, a head swap would be a good change.

1.7 60's out of the hole is NOT just fine. You'd be surprised how much ET drops with a drop of .1 or .2 in the 60s.

I'm really not trying to put you down Venom, just offering some 'advice' on the situation. I do agree that you're shifting too low. If your peak power is at 6200 rpm, you should be shifting higher so when it falls, you'll fall in the upper rpm range. If you're valve train is setup correctly, you shouldn't fear shifting it at 6500+. Just my opinion. But don't take this to heart, talk to Ed, he should have advice on this situation.

 

[Venom351R]

Theres a lot that can be improved on before any new parts are bought regardless. These were the first full pass's Ive made on slicks and I still need to fine tune my shift points. Launching on slicks is much different as those of you know who have done it so I know there are some mid 1.6's in there too.

If I really do need to go up in gear I would but nothing higher then 4.10's but before I consider a gear swap I need to watch and see what my RPM is across the line and see what happens with shifting higher. Considering that these were the first full runs Ive been able to make w/ the car all year I was quite happy w/ getting new best times but I realize there is still more in it just as it sits now.

 

[Killercanary]

Based on your graph:

You need to shift it higher. I'd start at 6400 and go from there. Try 6200 and then 6600 and see where the incremental go. Based on your tach comment here are some things I would do:

-Forget the tach and shift it where it feels right on one pass. As soon as you start to feel the car fall off shift it. You will be over shifting it at this point but it may show some gains. Again, look at the incremental, 60', 330', 1/8th ET and MPH, 1000', and 1/4 ET and MPH.

-What is your rev limiter set at? If you can change its settings, set it at 6500 and run each gear to the limiter, as soon as you touch it shift it as fast as you can.

Assuming you have a 26" tall tire, you are only at around 5200 with a 106mph trap speed. That will leave a LOT of time and ET on the table. Here's a good table to look at to judge your RPM based on trap speed.

http://www.mustangworks.com/cgi-bin/analyzer.cgi

If you want times that are indicative of what that combo is capable of, you need more gear plain and simple. Shifting it higher might help mask some of the lack of gear problems as they should help increase the trap speed in and of themselves.

A head swap is a waste of time and money IMO. I made 380rwhp with my 8.9:1 compression 331 with AFR 165's, and I'm trapping 121mph since swapping on my 185 comps. I run 26" tall tires and 4.10 gears.

I assume you are running the car at Epping and if that is the case, you have elevation and track conditions on your side so that isn't the problem.

 

[Venom351R]

Thanks paul that was very helpful . I'll take all of that into consideration when I go back this weekend. Im running the Street Shootout event. I wont be able to run the slicks but I'll have my MT Drag Radials.


I do realize my heads are not the issue as far as trap speed goes but would I benefit enough going to a Trickflow 205cc Head just based on a more power aspect on a 351W? Is it worth it just based on a price to power gained ratio? Keeping in mind I can sell these heads to offset the price of a set of 205cc Trickflows.

 

[Grn92LX]

If you want times that are indicative of what that combo is capable of, you need more gear plain and simple. Shifting it higher might help mask some of the lack of gear problems as they should help increase the trap speed in and of themselves.

Yup

A head swap is a waste of time and money IMO.

and yep Just like I stated earlier. Adding a larger head on your current set up will only make the lack of gear problem even worse.