The 'Dumb Question' Thread

[psycho bob]

Is it true that if you don't use it... you lose it?

Ok real question. What's a good source to read about racing tires. Bias ply, radials, etc. Not sure what all this is and which is better for what. I also always read not to mix them although saw a post where Derek @ amazon said it was ok.

i used et streets on the back with my regular street wheels/tires on front. was able to do it w/o any problems, but the car did have a slight sway on the top end

 

[Blackbird1084]

You can mix them. I have done this many times on many different platforms with no problems what so ever. The sway on the big end is normal for any bias ply tire with low air pressure. I ran 17 psi (hot) in the slicks on my 04 which gave me less sway on the big end than at 14 psi, but I still maintained mid 1.6 60fts. Using a wider tire, properly inflated, and better suspension is going to result in a more solid overall feel than sloppy stock parts and a skinny slick that's low on air.

 

[Noclutch]

I will be a little long winded here but I hope others who have gone this route can chime in or positive feedback on similar combo would be nice.
I have to make a choice but it all sits on this:

I have a set of dr and will be selecting a converter and it needs to meet 2 sets of plans.

Plan 1 is a 1/8th track and a 125 shot 2nd gear at 4k.

Plan 2 is a 1/4 track na.

I have 06 GT auto, UDPs, LT's, o/r x, LCA, cmdp, CAI and 4.10s, comp 127200 cams. I run a 93 tune from Brenspeed and on stock pirelli 235 17" tires the best of 12.83 @ 107.7 with a 1.990 60'.

This was at stock weight with 3/4 tank spare and all the works with a 220lbs driver.

Pulling the swaybar and getting the weight down by pulling the nonessentials doing the shortbelt and all will be done and no reason to comment on plugs, tune, and fuel pump as that is already sorted out so onto the dumb question ....which Converter?

The PI is the one I will buy but being this is a double duty expectation what should I get?

3k too low for na or 3500 too high for n2o or since I am not hitting until the car is in second past 4k it does not matter? I know track conditions matter and too high could set me up for a good or bad year with the wrong investment.

Thanks.

 

[Blackbird1084]

If your going to spray get a converter with anti-ballooning plates for nitrous. Get a 3500. Depending on what company you buy from you can request the converter be made tighter for nitrous and get a 4000 stall then have the best of both. Either way it'll be a good drop in et.

 

[retfr8flyr]

Give Chris at Circle D a call and he will fix you up. One thing I would recommend is while the trans is out get the TCI hardened input shaft and billet servos installed. I think you can get them from Chris. It's an easy install while the trans is out and will help the trans hold up under the N2O.


Earl

 

[woah]

Put it to you like this, my wife loves to ride along at the track. I let her ride in the mustang and every pass was a a solid and consistant tenth slower than by myself. She's a petite lil thing at 110 lbs. I havent pulled too much off my car yet but I'd like to dig into it a lil.

sadly, when my wife rides in the car, I lose more like 2 1/2 tenths

 

[Marc s]

sadly, when my wife rides in the car, I lose more like 2 1/2 tenths

That's not uhmmm. . . . . . .forget it.

 

[BlackSunshine]

Serious question and have never had a straight answer:

Explain why "tire spin" usally equates to a higher trap than "hooking"?

The E.T part of the equation is simple enough, but I would really like to know the physics of this conundrum.

 

[Blackbird1084]

It's hard for me to explain the physics. The general assumption is that with the increased tire speed, that is usually involved with tire spin, gets the car in its power quicker than if it dead hooked. I'm sure there is a more intellectual answer, but that is what I can gather as of right now.

 

[Nickoli]

ok this is a long read but I found it very interesting. A friend of mine and long time drag racing expert Bret Kepner posted this on his facebook about running the last race at KCIR. When you read it you will see what all is factored in to each run when a pro dose it. It might not be the most exciting race watching a stock DD go down the track but when you know all the info behind the pass it becomes interesting.

In the past twenty-eight days, much has been written of the impending closure of Kansas City (MO) International Raceway. From the original news release on Wednesday, November 2, 2011, concerning the track’s potential sale to the city to the incredibly swift completion of the transaction on Tuesday, November 22, the fabled dragstrip’s last month of life was a whirlwind of shock, anger, blame, misinformation and accusations levied at the current KCIR property owners, area residents and acting city council members. Caught in the crossfire with no way to escape onslaught from all sides were NHRA Div. V Director Rob Park, (a previous owner of the track), and current KCIR manager Todd Bridges, (who ran the facility but had no involvement in its sale).

Amid local media coverage of the uprising by KCIR customers which led to a meeting at City Hall with KC Mayor Sly James, word quickly spread the track’s final event would be held on Saturday, November 12. A huge crowd attended that race but KCIR’s own website insisted the 2011 schedule, which listed events on November 19 and November 26, would be completed.

Paul Hagen, one of Mr. Dirt’s longtime friends, had already earned the moniker, “The Grim Reaper of Drag Racing” for being in the last pair of racers at the final events of Gateway International Raceway, (Madison, IL), and Mid-America Raceways, (Wentzville, MO). Both Paul and Mr. Dirt made plans to attend the final day of racing at KCIR and elected to hold out for the November 26 date.

Unfortunately, a huge weather system moved into the Midwest on Friday evening, November 25, and the forecast looked abysmal for the Saturday program. However, the final event was rescheduled to Sunday, November 27, and, through close contact with Bridges and Park, plans were made to cruise west for KCIR’s Last Drag Race.

It was raining and cold when I met up with Paul and his son, Aaron, at the Wentzville (MO) exit on I-70 early Sunday morning. We planned to arrive before the scheduled noon start of the final race, a simple “Test-and-Tune” event, but the weather system covering the majority of the state made certain the day would be anything but comfortable; a cloudy high of forty degrees was predicted for the Kansas City area.

The Hagens own more race cars than I can count and both Paul and Aaron are championship-winning drivers among the best in the St. Louis area. Because of the forecast, however, they elected to take their “untested” new 2008 Chevy Impala while Mr. Dirt led the way with his infamous ’95 Mercury Grand Marquis. The three-hour drive included plenty of rain but the precipitation eased in western Missouri and all was dry when we arrived for the final time at 4202 Noland Road in beautiful Knobtown, Missouri.

Incredibly, KCIR manager Bridges and crew decided the final day of racing would be absolutely FREE; no admission was charged for spectators or race entries. In the tech inspection line, we were greeted by a handful of brave souls who scoffed at the weather. I stepped out of the car and fired up my Kestral weather station to find the corrected elevation as a staggering 682 feet BELOW sea level! At 38 degrees with a 15-mph headwind, it was a tad chilly.

I immediately began setting up the car for a day of testing. Because of the incredibly good air, some quick calculations showed the car to be capable of a 16.91-second elapsed time which, I reckoned, should put the sixty-feet elapsed time around 2.48 seconds. However, there were some additional variables to be added. The headwind would immediately add fifteen hundredths of a second. However, the car would be running about seventy pounds light since I had not topped off the fuel tank since leaving St. Louis. The Merc was about ten gallons down, (at seven pounds per gallon), from its normal configuration and, while the car should pick up seven hundredths of a second, I was also concerned about not having that “ballast” over the rear end on what was going to be a very cold surface. My recent experience with possible bad fuel while racing in Cordova (IL) kept me from “topping her off” as I normally would.

Therefore, subtracting seven hundredths for weight from the fifteen hundredths for the headwind, my original 16.91 prediction would be revised to a 16.99. After I set the rear tire pressure to my standard eighteen pounds, I concerned myself with the front tire pressure and my Reaction Times, around which this test session would primarily be centered. Since KCIR’s starting line “rollout” is pretty average, (around eleven inches), I would normally set up at twenty-five pounds of air in the front for launching the car while “shallow-staged” and the converter at full stall. However, I managed to catch my first head cold of the season the previous day and, because of the addition of Alka-Seltzer Cold Plus and a few Tylenol tablets to my system, I revised the front tire pressure to 26.5 pounds to set up for what I figured would be darned close to a 0.000 RT.

The weather conditions remained constant and, as I wheeled onto the starting line for my first pass, I opened the door and checked the track surface temperature with my TempGun to find it at 55.3 degrees…warmer than I expected. The tires held during the “practice launches” while heating the brake pucks and rearend lube going up to the line but, when I lit the “staged” bulb and put her up against the converter, I felt the right rear “chirp” just a bit before hooking solidly as the countdown began. I was aware my staging position hadn’t changed and released the brake to catch an 0.010 RT. All the shift points were solid and the “GrandMa” thundered through with a 17.24 at 80.49 mph.

Upon reviewing the timeslip in the pits, it was obvious I’d definitely missed the ET prediction by a ton. The “sixty”, a 2.514, was appropriate for the pass so I immediately checked the weather but the headwind had not increased. After a 230-mile drive, I figured the rearend lube and transmission fluid would’ve been at the proper temperature and, other than a very tenuous hold on the track in the beams, I’d experienced no other problems. The only way to verify if there was a problem was to make another pass…and I was already in line.

Sure enough, the Merc made a second pass at 17.26/80.63 and a third at 17.20/81.04. The sixty-feet ETs were all between 2.509 and 2.519 and the eighth-mile ETs were between 11.105 and 11.121. In other words, my staging position was solid and the only changes in the car’s performance came from the fluctuating headwind, which hovered between sixteen and eleven mph during those runs.

Later in the afternoon, the wind died down to between six and ten mph and the car responded with runs of 17.157, 17.174 and 17.162. Every launch was made at a water temperature of 188 degrees. While the speed increased to 81.35 mph, the “sixties” and the “eighths” varied no more than a hundredth of a second. Interestingly, the ambient temperature increased during this period to 43 degrees but the decrease in headwind still allowed the car to improve in elapsed time. This was verified prior to every pass by the weather station so I was pleased the car responded exactly as predicted.

At 4:47 PM, I made one last pass when the headwind was all but gone and the “air” went back to 650 feet below sea level. The prediction showed a 17.099 but the actual run was a 17.113 at 81.35. The “sixty” was exactly where it should have been but the “330 feet-to-660 feet” ET, which had hovered at 3.81 seconds almost all day, was off by…you guessed it…0.014 seconds (3.826)! What happens on a run between the 330-feet mark and the eighth-mile mark? My shift point happens, that’s what. In other words, Mr. Dirt blew the pass by short-shifting second gear by about 150 RPM. D‘oh.

My sole intention for true “testing” involved Reaction Times and you’ll noticed I haven’t mentioned any after the first pass. While I can term the day’s results “successful’, I ran into a small problem which negated several runs. The track surface temp never climbed above 58 degrees and, while I’ve never had problems with the Merc “hooking up” on launches in those conditions, there was another variable with which to contend.

The vast majority of the one hundred fifty entries on hand were street cars on street tires. A handful of race cars on slicks were present and the KCIR crew ran them in sessions. Because it was so cold, there was no traction compound used on the track, (thankfully!), and, because it was the last day of the track’s existence, no “dragging” of rubber or starting-line preparation was conducted. The KCIR starting line crew did a masterful job of mopping up exhaust condensation, (which came from seemingly every vehicle), and removing debris but, for all intents and purposes, the starting line was a real mess.

It’s nobody’s fault and, quite honestly, I’m not complaining. One of the reasons I enjoy driving “slow cars” is the fact virtually none of the standard “condition factors” affect my performance. On each run, it was quite a chore to find a spot on which to put the 4200-pound Mercury and that’s a challenge which will always make for a better racer. On several occasions, (after much searching), I managed to find an eight-inch “hole”, (well out of the normal “groove”), in which I very carefully placed the GrandMa to find the traction needed to hold the car at full stall.

Sometimes, it worked. Sometimes, it didn’t. On no less than three runs, (using both lanes), I found the car breaking loose the right rear Goodyear Eagle III upon release of the brake. The tire would spin a half or three-quarter revolution while still in the beams and before the car every moved forward and then hook solidly. This affected no other part of the run but…you guessed it…the Reaction Time.

Usually, tire spin lasts longer than a few inches but this type of “spinning in the beams” isn’t that unusual. Normally, I could adjust launch RPM to compensate but, in this case, the car was hooked solidly against the converter and I never got the impression the car was about to spin until it happened. Because of it, I wasted a few attempts in experimenting with RT manipulation.

Luckily, most of my runs were fine and I was able to fool around with front tire pressures. Having been through the situation before and knowing the effects of the medication, I kept a consistent amount of Alka-Seltzer and Tylenol in my system throughout the day. After the initial 0.010 RT at 26.5 pounds, I left the pressure alone and, on the next pass, the “sixty” improved eight thousandths which should have resulted in a 0.002 RT. Instead, I hit a -0.005 redlight.

Based on my standard formula of one pound of front tire air pressure change for each hundredth of a second in Reaction Time change, I dropped the pressure a half-pound to 26.0 to set up for a 0.000 RT; I figured it would be nice to have a "perfect light" on the final day of racing at KCIR. In an eliminations situation, I would never “set up” for a “triple-oh bulb” and rarely adjust the tires by a single half-pound. However, this was testing and this is why we test! On the next pass, (with a virtually identical “sixty”), I caught a -0.003 redlight.

I left the pressure at 26.0 and, on the last pass, hit a 0.006 green light. In all, my RTs never varied more than ten thousandths from the prediction so, as I stated earlier, I considered the test a success.

While I was running, so were Paul and Aaron. They managed to get their Impala SS down into the low fourteen-second range at over 96 mph. Paul also spoke to KCIR manager Bridges in hopes of continuing his “Funeral Director of Drag Racing” reputation and asked if he could make the last pass down the track. Incredibly, Bridges agreed and Paul came up to me just after my last run and said, “It looks like we’ll be the last pair and they’re going to dial us in!”.

The event was scheduled to run from noon until 5:00 PM and, the staging lanes were closed around 4:50 PM. Paul and I sat back and waited for the lanes to empty and I dropped the front tire two pounds to set up for an 0.026 RT. Turning to Paul, I said, “OK. It’s set up for a ‘twenty-six’. All you have to do is beat it!“. With Aaron videotaping the match, Paul and I rolled to the line at 5:19 PM. Because they finished up with cars on slick tires, my Eagles hooked solidly and I launched cleanly. I looked back just in time to see Paul catch an -.032 redlight but he “closed it up at the stripe” to only three thousandths of a second between us. I’d be lying if I said the illumination of the win light didn’t mean a lot to me.

As a matter of record, between the time we pulled into the back of the lanes and the time we staged, several things happened. The wind died…completely. The ambient light went away almost entirely and my “set-up” for an 0.026 RT was compromised by the darkness. The corrected elevation fell almost 150 feet while we sat in the lanes as the sun dropped below the horizon.

For all those changes, I hit another 0.010 RT and the car stepped up to a 17.05/81.55 while Paul “backed into me” with a dead-on 14.523/81.90 in a masterful job of matching the Merc’s pace. I got to the stripe first by 0.003 seconds so Paul, in fact, was the last racer across the stripe in a race at KCIR.

As we stopped at the timeslip booth, Kyle Marcum performed a huge burnout in his green Ford Mustang Super Gasser, backed up, staged and then idled down the KCIR quarter-mile at 47.469 seconds, 21.42 miles per hour, in what was a very emotional final timed run at Kansas City International Raceway.

Paul and I returned to the staging lanes to find a huge group of racers fans and family members out on the starting line hugging and choking back tears. Todd Bridges, whose entire family works at the track, offered to sign our timeslips and posed for photos with us and just about every other person on the property.

And then, it was over.

I had the opportunity to chat with several of KCIR’s drag racing heroes during the afternoon; among them, chassis builder and Pro Mod racer Terry Murphy, second-generation Pro Stock star David Schorr and Top Fuel veteran Dale Wilch all stopped by to visit. All had the same subdued sadness on their faces for a lifetime of memories about to disappear. I talked to many local racers while in the staging lanes and all were still in shock over the loss of such a huge part of their lives. I think the tone of the day was set when I heard the announcement around 4:30 PM that all food at the concession stand was free to everybody until it was gone. For some reason, that really hit home.

For me, it was the end of a thirty-five year relationship with KCIR. I announced many races there over the years beginning when Chuck Harmon owned and operated the track with his wife and a very curious and knowledgeable young son, Charlie. That little kid would go on to become the track owner and operator, an NHRA Division Director and, eventually, the guiding force behind both the National Muscle Car Association and the National Mustang Racers Association. A few hours after I type this, I’ll be heading to Orlando (FL) where I will host the NMCA and NMRA season awards ceremonies for that same little kid, Charlie Harmon, who earned so much pride from his now-departed father.

I announced so many wonderful events at KCIR. From its many AHRA National Events, (traditionally the AHRA Summer Nationals although there were others), to UDRA National Events to NHRA Division V races to NHRA National Opens to Bob Hendryx’s Chevy All-Star Weekends to NMRA/Ford Nationals to just about every conceivable match race and even regular weekly events, we were there in blazing heat, freezing cold, pouring rain and even tornadoes. It was a big part of my life, too.

We pulled out of the gates for the last time and, before the trip home, I put $41.53 worth of gas in my car on Noland Road and Paul would do the same. We stopped at the Noland Road McDonald’s and, between the three of us, ate over twenty dollars worth of food. As we pulled onto I-70, I looked at all the hotels at the Noland Road exit and, from the worst to the best, remembered the dollars we spent to stay for all those three-day weekends. Although the city decided to turn their dragstrip into a park, I can’t say that park will support the community the way WE did.

It was a long drive home.

Next time out, I’ll be hovering at 103 career wins, 141 career finals, 181 career semi-finals and one trillion losses…but Mr. Dirt will never make another run at Kansas City International Raceway.

 

[Blackbird1084]

A very good read. But also a sad one as it hits home for me. I've raced there as well many times. It's where the first two National LTX Shootouts were held and where I won my 2 LTX bracket titles as well as my LTX index title. I've already seen ads on Craigslist were guys are selling their cars and trailers. That track will be missed. The city in not realizing the importance of the track will soon see a huge jump in street racing and in turn accidents caused by such. They'll also see a relative drop in revenue and possibly closings of many hotels in that area.

 

[cm581978]

Reviving this thread, but is a burnout needed for MT ET Streets II? I am a burnout and drag radial tire noob, but am planning on running these tires in the next few wks? Mods are your normal bolt on (Cai, Exhaust, Tune, 4:10s)

 

[JerryC]

Like any tire, it depends. If they hook without a burnout, then no. They stick really well to a prepped track, its going depend on how much hp you have, suspension, etc....
Having said that, most tracks want you to do at least a small burnout to clean the tires of debris picked up in the pits so you don't contaminate the start line and the track.

 

[Swarzkopf]

It's worth turning over any tire a few times, even if a John Force burnout isn't required.

If you have to drive through the water box, make SURE you do a burnout to dry the tires.

 

[AJCrader]

Just a quick FYI...and not towards anyone that has actually raced...learn where the starting line is!!!

I worked at a track for 7 yrs, as well as raced, and nothing bothered me more than a bunch of guys talking up their cars/experience racing, yet they would constantly line up at the tree or with their rear tires in the beams.

With that said, another big pet peeve...make sure that if you have any thought of any failure to the car pull to the outside of the track, out of the groove, and stop ASAP safely...it only helps you, it helps everyone else too!

 

[bunkered13]

Just a quick FYI...and not towards anyone that has actually raced...learn where the starting line is!!!

I worked at a track for 7 yrs, as well as raced, and nothing bothered me more than a bunch of guys talking up their cars/experience racing, yet they would constantly line up at the tree or with their rear tires in the beams.

With that said, another big pet peeve...make sure that if you have any thought of any failure to the car pull to the outside of the track, out of the groove, and stop ASAP safely...it only helps you, it helps everyone else too!

i couldnt have said this better myself. it pissed everyone off when you oil all the way down the track because you decided to stay in it. Not only does it take a while to get the mess cleaned up, but if you start getting oil/water on your rear tires you run the risk of hydroplaining and wrecking, possibly hurting yourself or others.

 

[NUTCASE]

YES on above

I have seen quite a few accedents at the track that were the result of somebody not letting up when the car was obviously not going to hook right.

this is usually happens with a younger guy, with a newer sports car.

first time I actually saw this it was when the 350Z first came out. the kid had not made the first payment on the car yet. after talking to him found out he could not even TELL when the wheels were spinning. he simply had no idea why the rear was swaying and just held down the gas because he did not want to loose (TnT night LOL)

 

[AJCrader]

YES on above

I have seen quite a few accedents at the track that were the result of somebody not letting up when the car was obviously not going to hook right.

this is usually happens with a younger guy, with a newer sports car.

first time I actually saw this it was when the 350Z first came out. the kid had not made the first payment on the car yet. after talking to him found out he could not even TELL when the wheels were spinning. he simply had no idea why the rear was swaying and just held down the gas because he did not want to loose (TnT night LOL)

I have seen people of all skill levels, all kinds of cars not pull over. I have seen an extremely experienced racer of well over 40 yrs oil down the track from the hit of the throttle all the way to his pit(leaking out the exhaust behind his tires, smoking more than I have seen any diesel, all be it white not black smoke) was told to make sure it was fixed, then came out in the other lane and do it again...had to 86 him from the track for a year, and from what I know he never went back

 

[NUTCASE]

ok just thought of my question

if you are on a track that is oriented slightly downhill, and you have a manual, how do you stop your car from rolling though the staging beams while the clutch is down with one foot and the revs are being held up with the other?

had this problem at one track I would go to sometimes. funny enough when the track took new ownership and they got serious about track prep the problem suddenly stopped.

the only thing I could think to do was either wait till the last possible second to take my foot off the brake and bring the revs up or just not go there.

I tried holding the e brake and then dropping it before the green, but apparently I don't have the coordination to really pull it off and get a good R/T

 

[scramblr]

Line locks