InsidiousGT

Ok, second time to the track, 6 runs done now with the new car and I'm getting a bit frustrated. I'm hoping you guys here can provide some feedback to help me get more out of the car.

Below are a few things that happened last night and a few questions I have in general. Feel free to comment on one or all of them, but please keep it positive. I know I'm amateur. I've been racing about 3 runs a month for 4 years now, but only two nights with the new car.

One other note, I don't power shift. Its not that I can't, I just don't like the amount of stress it puts on the drivetrain. I am pretty darn close to powershifting though, micro-lifts you might call it, I'm pretty much rev-matched when I dump the clutch.



Run 1) Launch was pretty decent, let the clutch go with only a tiny bit of slippage at around 3k rpm. They chirped a bit, but the 2.0 60' was the best I've done in this car so far. Little chirp and associated wheel hop when I hit second. Shifted right around for 6500 for all 4 shifts. I think my 5th gear shift was almost entirely wasted, by the time I got it into gear I saw the trap light. Run was the best I've done so far, 13.4 @ 108.

This run makes me wonder where I should be shifting, since I know my 5th gear was entirely wasted here. Just driving with the car I can definitely feel the most pull from 3500-5500, but with the gears so sequential, I'm hardly ever in that range. Should I be shifting earlier to maximize my 5th gear or will I lose too much by not having that high end horsepower?

Run 2) I started thinking the mild wheel-hop I experience in 1st and 2nd might be hurting me, so I tried launching a bit lower and slipping the clutch just a tad in second gear. I shifted at redline every shift, hit the trap right at the redline in 4th. Was 2.1 60' and 13.6 @ 109.7.

It was my highest MPH yet, which made me think I was on the right track, but riding the redline in 4th makes me think there is ET yet to be had if I shifted into 5th.

Question) If I'm not gunna powershift the car, I know I'm adding some amount to my ET's just by that fact, but I didn't think it would half a second. I've run around 13.5 three times now, but I feel like I should be able to get closer to 13 flat or under with the horsepower in this car. Is that not true?

Stinger1982

first is this in a 2011?

second shift at 6850ish and DONT USE 5th!!!!!

no offesne but shift faster. I dont powershift either but I have EXTREMELY fast shifts.

Our 60's are about the same and teh MPH's are close. So its after you get it off the line your having your issue.

Please post your entire time slip so i can compare and analayze it with mine and talk with you about it.

Driver72

What track are you at?
What is the DA on the day you went (temp, humidity, atmospheric pressure, etc) that gives you the literal elevation you are at. If you aren't familiar you could really be at say 1000 feet in actual elevation but if temps are high, humidity is bad and pressure is bad, the literal elevation could be 2500-3000 feet.

In those cases running a 13.4 isn't too bad in a stock 5.0

However, you said you are shifting at 6500 rpms in all gears....why?
1st-3rd should be done at 6800-6900 rpms.
You want to get the shift in just before hitting the limiter. Maximize the power multiplication of the lower gears.

As I've said many times before, what you mentioned is some of the problems of the 3.73's and drag racing.

Launching.
The 3.73's make launching a bit more tricky, too much power put to the ground and with the 3.73's you spin to easily.
Shifting
The 3.73's also allow more wheel spin in first, but also during the shift to 2nd. That wheel hop and associated wheel spin you are feeling is costing you time.
Further, with the 3.73's that need to shift into 5th just as you are crossing the line, as you noted, hurts the ET and trap.

Hence ONE of the reason I ordered 3.55's in my car.

We here in So Cal don't have ANY really good drag strips. The closest decent one is Famoso, but it's still 100+ miles away from LA.
Sacramento is 400+ miles away and that's a good track but well known to be optimistically fast, especially in the trap speeds.

The 3.55's will allow a bit more aggressive launch without as much wheel spin, not as much wheel spin hitting 2nd, and most importantly allows you to finish the 1/4 mile in 4th with a few hundred rpms left in reserve before hitting redline.
Not sure if anybody with 3.55's has actually hit the drag strips yet as it seems the vast majority order the 3.73's or stick with the stock 3.31's
There's no doubt that a 3.73 car will pull a bit harder in each gear than a 3.55 car, but the 3.55 car can stay in gear a bit longer, plus if you do any illegal rolling runs against other cars on private, deserted or Mexican highways, most often you start around 40 mph and go to about 120 where a victor is pretty much known at that point.
The 3.73's again will require that shift to 5th to hit 120 mph (or they need to shut down around 111 mph) but the 3.55 geared car can go to about 119 mph.
And rest assured a 3.55 car will accelerate harder in the top of 4th from 111-120 mph than a 3.73 car will in 5th (from 111-120 mph).

What you need to do to maximize your times at your track is practice the launch (you seem to have it down pretty good if you are getting 2.0 60 foot times on stock tires) you may be able to get into the 1.9's.
You need to take at least 1st-3rd to redline and shift before the limiter.
If you don't have the stickier Brembo Brake package tires, upgrade to better tires for better traction too.

Then of course if you still want more, mod for power.

Ltngdrvr

Don't know what your budget is but an extra pair of wheels and drag radials will fix the traction problems and get those 60's down where they should be. if you do this, make sure you get tires that are about the same height as the stock tires.

And like was said above, shift higher and stay away from 5th gear. You have enough RPM potential stock to hit about 115 mph without hitting the rev limit in 4th.

InsidiousGT

Yes 2011, with steeda CAI + tune.

I do shift fast. Its a hard enough shift that if I'm not careful I spin the tires in both 2nd and 3rd.

Here are the slips, sorry they are so light, scanner kinda stinks.

InsidiousGT

Slip says

BAR 29.90
Deg 68.9F
Hum 99%
Calt: 2002

Stinger1982

the numbers start to really change around the 1000" mark, I have two tenths on you everywhere after launch.

i am just not sure. My run was in hotter weather with a stock airbox. I am just not sure.

I was chirping on all shifts (even into 4th) but I NEVER shifted to 5th I think thats a big part of it.

Your one run where you were at redline @ the finish I just dont know what the difference is.

InsidiousGT

I definitely lose less in the later 1/8. I'm behind a lot within the first 1/8, but those shifts, even on the Brembo rubber, any harder and I spin em all over the place.

Ltngdrvr

Most all of your differences can probably be traced to RPM and wheelspin, you may not hear it but it is happening.

InsidiousGT

I really cant push it any more than this on the stock tires. Notice I said I do 3 runs when I go but only posted 2

My third run my plan was to get as close to redline as possible in every gear and shift a bit harder. Spun em in second, spun em in 3rd, chirped in 4th. 14.8 @ 97

Ltngdrvr

Drag radials bud.

InsidiousGT

Cant do it. I have to drive 100 miles to the track and 100 miles back.

I'm starting to wonder if I should just leave the traction control on. I notice when I'm practicing my shifts I can really shift hard and it does a good job of keeping the rubber down.

xkornkidx01

Add some new upper and lower controls arms as well

Stinger1982

I assume you mean a third link because this chassis doesnt have UCA's
no need for an aftermarket thrid link in this case. Street car thats rarely at the strip.


chrome moly LCA's and all axle hop is eliminated

RedCandy5.0

So you have a stick? Dyno should be about 370rwhp at average. Add Steeda CAI/tune this adds 40+ more rwhp. So you are at 410rwhp and only running 13.4? Something stinks here. Did you run your car stock? I seen even though some CAI are gaining on the dyno some are hurting on the track.
Have you had your car dynoed to make sure there are no problems?

Ltngdrvr

What's a 100 mile drive got to do with it?

Heck, bolt them on at home and drive to the track, race, drive it back home and swap them back to your regular tires. Nothing wrong with that.

On my old Gen2 Lightning I used to just have the drag radials for my everyday tires as well as race tires. Consistantly got 1.67-1.71 60's with them on a 4800 pound truck.

Driver72

You definitely won't be able to stay in 4th on 3.73's with intake and tune.
3.73's are good for about 111.8 mph based on gearing and Brembo brake package wheels/tires.
But remember trap speed is average speed over last 66 feet of run, so if you get to 111.8 mph as you are crossing the line your trap speed will be about 110-110.5 mph.

On a tuned car you will easily exceed that in the 1/4 on a good track with 3.73's (again with 3.55's you should still be able to stay in 4th).

The problem most likely is the track.
It's NOT relevant for others to compare their time slips and trap speeds from other tracks. It's just pointless and has no accurate comparison basis.
You could be doing everything perfectly correct and as good as it gets, but maybe your track runs uphill by a few feet, and other people's tracks run downhill by a few feet.
Very few tracks are perfectly level from the lights to the stripe. NHRA allows some variation.
Heck California Dragway runs uphill by 4 feet over the 1320. Other tracks like Cecil run slightly downhill (another reason you see great times at that track).

Compare your times to what OTHERS have gotten on your same track with similar DA's, and preferably on the same day.

Tracks have more variance between them than dynos do, yet it's still always funny to read and hear people compare dyno plots too and say, "you should be getting higher than that with those mods, I dynoed 10-15 rwhp more than you on my dynojet."
If that person did not dyno on the SAME dynojet, the comparison is irrelevant, and that person with the higher dyno may in fact dyno LESS had he dynoed on the same dyno the other guy did.

InsidiousGT

No, nowhere to do it around here.

InsidiousGT

Yes, a few weeks back I ran a 13.5 @ 108 stock.

Whats interesting to me is that the run where I slipped the clutch a bit on launch and 1st->2nd, I trapped just about 110. So, why the added MPH that run even through the ET was down by 0.3?

xkornkidx01

mY BAD... I mean "3rd link"