TRSCobra

Ran a couple times at the local dragstrip, and it seems my traps are a bit low for my mods. I've got heads/cam/cat back putting down 510 whp on a mustang dyno. Granted, I'm on the stock runflats and inexperienced with this car, but don't these things run higher traps stock?

DA was ~609' and the track is an old airstrip, so I was spinning quite a bit (as evident from my terrible 60').

KLLRVET

traction. or lack thereof has a lot to do with your low mph.

Stock tires and lack of experience/skill also have a big hand in it the SLOW ET and mph. It takes the correct setup, and more importantly LOTS of experience to get the car down the track fast, even if it makes gobs of power. It is a waste of time, and dangerous to try to make a real pass at your power level on stock tires

TRSCobra

I knew the 60' time made a large effect on ET's, but I figured my traps wouldn't be too far off from a good run. I shifted the hell out of the car very quickly with no missed shifts, either...

My last time at this track was 3 years ago driving a heavily modified Subaru Legacy GT 5mt to a 12.6 @ 112 mph. Pretty sure I was having traction (or clutch) issues then, too, but the AWD got me a 1.8 second 60' time.

I need to print out the last sentence of your quote to show my wife! Justification for some drag radials!

propain

Your MPH seems low for your WHP.

NORTY

Why would anyone drag race a car set up for...? No wonder it traps only 122. A real drag racing car traps 325+.
Talk about a snail's pace.

8850

Depending on your tune, if you let it idle for any period of time before launching your IATs would most likely be high and thereby pulling timing. Another possibility is knock retard. Some tuners tune to the ragged edge on the dyno but on the track by 4th gear you can get kr that did not show up on the dyno.

Best to log with a tuner like HP Tuner and see what is going on. Maybe just a few adjustments would make a big difference.

LS7 BUD

What...?

OP yes your trap speed seems quite off for your rwhp... When I was 512rwhp I trapped 125-126mph on crappy run-flats with a 2.2 sixty foot... Stock clutch...? Maybe your car is down power at the moment...

camirocz

low trap speeds is because you are finishing the quarter mile in third gear.You need to shift into 4th at the 1000 ft mark and you will easily add three to four mph to your slip.Run lfats are garbage get some decent rear tires and 11s will be a joke with those mods.

camirocz

Fourth is a must if you dont get into fourth you ll never run a good time or a high mph.

whitehooptie

Slow shift speeds can also affect MPH in a manual trans car.

TRSCobra

I wonder if the torque app and bluetooth obd scanner will be able to log the necessary parameters.

How did you know that?! I shifted into 4th on my first run (right before the 1/4 mile mark), but kept it in 3rd for the run I have posted. I ran a 12.6 at about .75 mph slower that time. Doesn't shifting at redline give the best times?

VetteVinnie

This was me at around 500rwhp (SAE Dynojet) with Nitto Invos. It was a 60-130 event (hence no water in the waterbox). We had the option to stage for a 1/4 mile if we wanted since it was a private rental for the afternoon. I'd say your trap is a bit low, but I'm sure it will improve over time:

TRSCobra

I wouldn't say my shifting was too slow, but I wasn't powershifting, either.

Just remembered there was a ZL1 camaro there running 13.0 @ 114 mph. Maybe that track is just that bad?

Beach Bum

Your traps are definitely low.... 510 rwhp on a Mustang Dyno, hence, somewhere around 520-530 on a Dynojet, is good for 130+ mph traps, even in summer air if you hit your rpm points (Very important) and they are crisp shifts, especially in 600 ft air.

You also need to be hooked up before the top of 1st gear.... if you go into 2nd at a slower speed than 1st gear is capable, then your MPH will definitely be down. If you short shifted by accident, then your mph will also be down.

If you're confident you were hooked up by the top of 1st and ran that gear through and then hit your high 6000 rpm shift point and it was at least fairly crisp shifts.... then maybe clutch issues ? Just guessing. Practice will certainly improve as well.

TRSCobra

I was hoping for at least 128 mph. It was only like 65* that day, but very windy (head wind?). I can't recall when I shifted out of first, but it was spinning even in second. The track is mostly just old asphalt except for the starting line. I wish I didn't forget my go pro, so I could review just how I did. Traction control was off, BTW.

propain

Who did the tune? Dyno numbers can look amazing and translate to crap in real world conditions.


Your MPH should be 128+ with your power and that DA.

SloZ06

You might want to see thru hp tuners if your tb I'd opening all the way. My tb was opening only 67 percent. 88 percent is actually considered 100 percent actuation. I had to replace my ecu. The best I got was 10.8 at 132 with that issue. Of course 60 ft was a 1.7

SloZ06

Oh and I out down 555 rwhp and 500 tq. With intake,tb, and head porting with a midrange cam.

Rock36

This reminds me of the "drag strips" in Germany, which are mostly borrowed/rented airstrips where they can not lay down VHT for environmental reasons and to keep the airstrip uncontaminated.

On these "strips" no one, and I mean NO ONE, ever got anywhere near the ET/trap speed that you would otherwise expect. Even with drag tires, getting below a 1.8X 60' was challenging on a RWD car for example.

Guys stationed there in the military would invariably return back to the states, run on a normal drag strip again, and immediately get much faster times... same driver, same car. The typical DA in Germany doesn't help either (~2500ft), but I'm willing to wager this is a significant part of your problem if the track is as you describe.

Do you have any normal dragstrips with standard surface prep in your area? If so, I would suggest going to one of those before you start freaking out too much about your car and/or your tune.

8850

128 mph is definitely doable with heads and cam. I assume headers too? I ran a 127.68 mph with factory heads/cam on a 60s* day. I was shifting at 6500 rpm. Was into 4th quite away from the finish line. Even shifting at 6500 I dropped to about 5000 rpm when I hit 4th. Of course this is with my factory cam which peaks at about 6300 if I remember right so 6500 is about the right shift rpm. I only ran an 11.31 as I had a bad 60' too. My car did not hold traction at launch either due to my lack of experience racing a manual.