[roninsoldier83]

So, I used to be a moderator on a local Mazda board, and since I recently picked up a project autoX car (NA chassis Miata) I decided to head out to a local Mazda install party/meet. Which, it was pretty cool, a couple of the Miata guys there had V8 swaps (one running a Chevy small-block and another with a Ford 302), as well as a local RX-7 with a swapped LS2 in it. Either way, my brother was with me in his '06 GTO, and since the meet was being held close to Bandimere, we figured we would get a couple passes in after the meet was over. Although they were closing at 5:00pm, so we didn't have too much time.

For reference, I have a 335xi that is running Cobb AP stage 1 (91 octane) that is otherwise bone stock. On top of that, I was running stock run-flat tires, had a car seat in the back, as well as jumper cables, a small air compressor and other misc. crap here and there haha. I'm also about 6'2" 215 lbs, so I'm not exactly tiny haha. My car is a 6MT.

This was my first time EVER launching the 335xi (not as easy as my old STI to say the least), and today while we were there at Bandimere, the DA was 7700 ft.

My first launch, I babied it and launched around ~2800-3000rpm, which produced a very sub-par 2.1 60 ft (it's been a while, but I used to pull 1.7-1.8 60's with ease regularly in old my STI, but this can't/doesn't launch like a Subie, going to have to work on it). Either way, it was my first ever pass in the 335xi/first launch ever in this car and it was good for 13.914@102.31 at Bandimere Speedway. For reference, the car I was running was a new Camaro SS, I have no idea what was done to it, but it didn't sound stock (it went 14.975@101.29).

I only got one more pass in before they closed, and attempted to slip the clutch around 4500rpm, and the damn clutch stuck to the floor!! Pissed is an understatement... I tried shifting into 2nd around around ~15-20mph, had to completely let off the gas and kick the clutch a couple of times to get the damn thing unstuck... has this happened to anyone else on this board? For reference, it didn't stick on the floor mat, it just stuck in general... which is too bad, as I would say with a higher RPM launch like that, I think I could have easily run a mid-13 around ~103mph or so. As you can see, I picked up ever so slightly more speed in the back half of the track on that run, but the sticky clutch really hosed me. Considering having the dealer take a look at it haha.

So, only two runs at Bandimere today, but I'm confident that on a nicer day, with a little practice launching this thing I could likely run mid-low 13's at 103-104mph.

Here are the slips, I'm car 957:


For reference, I wasn't really trying to hit a perfect R/T, didn't pay much attention to it.

For another reference, my brother was there with his 400hp LS2 powered '06 GTO 4AT (car 956), and these were his best passes:



^^^So, for all of you sea level guys, this is what 7700' DA does to a car haha! Typically, those cars (LS2 GTO's) running the 4AT seem to trap anywhere from 101-105mph at sea level, whereas my brother couldn't pull any better than 92-93mph up here. Last I checked, the highest trapping 335xi up here running full bolt-ons & meth was trapping around 106-107mph, so considering my car was running only the AP map 1 on 91 octane, otherwise bone stock, fully loaded, I'm pretty happy only trapping 4-5mph slower haha.


Either way, just felt like sharing, and when I learn to launch this bugger (might investigate the clutch sticking issue), I'll be sure to post up more high elevation times.

Happy modding!

-Brandon

EDIT: To get a rough idea of what my brother and I's car's should be running at sea level, a person can enter their information into a DA calculator:
http://www.dragtimes.com/da-density-...calculator.php

I pulled weather data on that site as well, for 4/16/2011 at 4:53pm (shortly after our runs) at Bandimere Speedway, and it came up with a DA of 7590 ft. I then punched in our times, and got the following:


^^^Even though my car isn't "extensively modified", it's a 3800 lbs pig (xi sedan) with a higher drivetrain loss (AWD) running on 91 octane, so at sea level, I suppose that would be about right, I would think it would pull low 13's @106-107. Fairly accurate.

Same for my brother's '06 GTO:


^^^His car is stock, but with a not-so-impressive 2.3 60 ft time, 13.8@102.6mph would sound about right.

Notice how much more affected NA cars are up here in comparison to boosted cars... just thought I would point that out

[momstmg78]

Good info on high altitude. Thx

[dmurray14]

That's nuts. I remember driving through Denver on a rally in '08 with an E92 m3, almost went to the dealer cause we couldn't figure out what was wrong with it.

[roninsoldier83]

Originally Posted by dmurray14

That's nuts. I remember driving through Denver on a rally in '08 with an E92 m3, almost went to the dealer cause we couldn't figure out what was wrong with it.

Yeah, elevation really hurts... ever more so for naturally aspirated cars.

[roninsoldier83]

On another note, here's a few pics of some of the Mazda's at the meet today, as well as a few pics of my 335xi & my brother's GTO at Bandimere, it was a fun day to say the least

[AltecBX]

That 335xi spanked that Camaro SS..
Anything in it?

[roninsoldier83]

Originally Posted by AltecBX

That 335xi spanked that Camaro SS..
Anything in it?

Yep, my 335xi spanked that Camaro SS by about a full second (although only about 1mph difference in trap speeds). I have no idea what was done to the Camaro (didn't sound stock), but the only thing my 335xi is running is a Cobb AP stage 1 OTS map. Other than that, bone stock, to include running a car seat, half tank of gas, stock run-flats, jumper cables, a small air compressor and a few other things here & there (complete daily driver weight haha).

[335why]

LS1 ...Best motor ever

[forza1976]

Nice Brandon. Glad you had some fun up at Bandi. What a killer the DA is even with the nice temps. We ran into the same thing last weekend.

[marv85]

I seriously did not imagine altitude would make this big of a difference!
Cool cars, it would have been nice to those LSx swapped mazdas do 1/4 miles runs. any idea how much they trap?

[Jeff@TopGearSolutions]

Man N/A cars really get the sh*t end of the stick up their.

I visisted CO a few times. I was light headed for the first couple days and needed plenty of water.

[whitecord]

i had my clutch stick. i was doing the same thing launching at a high rpm and slipping it to keep it from spinning. with my 135i i can pull 2.0 60s launching less than 2k so the high revs are not necessary. with better tires and less hondas dragging water up i am sure i could improve that to a 1.8

[roninsoldier83]

Originally Posted by forza1976

Nice Brandon. Glad you had some fun up at Bandi. What a killer the DA is even with the nice temps. We ran into the same thing last weekend.

Yeah, that DA is a killer! For our elevation, I was ok with my first run (although I know I can break mid-low 13's with some launching practice & better weather), but my brother wasn't to pleased to say the least haha.

Originally Posted by marv85

I seriously did not imagine altitude would make this big of a difference!
Cool cars, it would have been nice to those LSx swapped mazdas do 1/4 miles runs. any idea how much they trap?

Yes sir, we really get the shaft up here haha!

I don't know what the swapped Mazda's run up here, but the guy with the red Chevy SB'd Miata said he tried to run a while ago, and they wouldn't let him past tech, as the NA chassis Miata is supposedly 1 inch too short for an "approved" motor swap or something to that effect. The guy is an engineer, so he was talking about lengthening his wheel-base to get it passed tech haha!

Originally Posted by Jeff@topgearsolutions

Man N/A cars really get the sh*t end of the stick up their.

I visisted CO a few times. I was light headed for the first couple days and needed plenty of water.

+1

All cars get the shaft up here, but N/A cars even more so, haha.

[Litos]

you'd have to have an 11 second car to get into the high 12's in CO HAHAHA !!!!

terrible.....

[raceyBMW]

^Pretty much, I'm sure the guy here that ran in the high 12's at 107mph with full bolt-ons and meth last weekend (91 oct) would have been into the 11's at sea level, or really close to it.

I put in a JB4 for one run last weekend and pulled a 13.7@104mph, RWD, auto with about 95octane or so. I had no other mods on at the time, just the tune. Isn't that what completely stock guys are doing at sea level?

Roninsoldier, you need to try some mixing race gas with the 91oct. next time, I bet it will help out.

[roninsoldier83]

Originally Posted by raceyBMW

^Pretty much, I'm sure the guy here that ran in the high 12's at 107mph with full bolt-ons and meth last weekend (91 oct) would have been into the 11's at sea level, or really close to it.

I put in a JB4 for one run last weekend and pulled a 13.7@104mph, RWD, auto with about 95octane or so. I had no other mods on at the time, just the tune. Isn't that what completely stock guys are doing at sea level?

Roninsoldier, you need to try some mixing race gas with the 91oct. next time, I bet it will help out.

Nice ET/trap for this elevation! Just curious, what map were you running on the JB4 with your ~95 octane blend? I can't tell you how many times I've second guessed myself on buying the AWD xi.... it's great in the snow, but I would have liked to have saved 200-300 lbs and had a smaller drivetrain loss haha. Sometimes I think instead of buying the Miata, I should have bought the RWD 335i and an AWD beater Subaru for the winter haha!

I'm thinking the next time I go back, I know they have that 104 unleaded pump on site, I might dump in a few gallons, but we really went on a whim yesterday, no track prep (fully loaded car, pump gas) and we got there so late we just went through tech and hopped straight in line to try and get a pass or two in before they closed. Had I known we were going to the track earlier, I might have taken some of the junk out of the car/trunk, put in a couple gallons of the good stuff, maybe bought a bag of ice to help with the intercooler between runs, practiced launching a few times on a back road somewhere and tried to get there in earlier in the morning, when temps were lower and the DA was closer to 6400 ft (vs 7600-7700) haha.

Although for now, I want to address the clutch sticking issue under hard launching before I waste my time going back. I'm assuming there's either air in the lines, or a problem with either the slave or master cylinder. I'm assuming it will be an easy fix, but I tried launching it on a back road today at higher RPM to see if it was a freak occurrence, and as it turns out, it really is just sticky under higher RPM launches, so I'm going to need to get that taken care of before I head back out to Bandimere. The ET is made in the 60 ft IMO, and there's no reason to waste my time trying to drag it if I can't launch the damn thing properly haha.

[Dackz]

I put down a 13.8@101 with a JB+ only last year and its only turned up about 10-15%. You should be able to get a low 13 for sure with an XI but good luck with a day where the DA is low. I dont think that exists here.

I cant wait to get my car to Vegas friday night and see what it runs down there. Should be interesting to compare. Im going to run it the same as I would here to see the difference of ~2200ft strip to a ~5800ft strip.

[marv85]

Originally Posted by Dackz

I put down a 13.8@101 with a JB+ only last year and its only turned up about 10-15%. You should be able to get a low 13 for sure with an XI but good luck with a day where the DA is low. I dont think that exists here.

I cant wait to get my car to Vegas friday night and see what it runs down there. Should be interesting to compare. Im going to run it the same as I would here to see the difference of ~2200ft strip to a ~5800ft strip.

Would be interesting to see the difference, keep us posted!

[Dackz]

Originally Posted by marv85

Would be interesting to see the difference, keep us posted!

Ill do my best. The only difference may be octane, but in general the blend should be close to the same (I hope). This past weekend on 4 passes I clocked 14.0-14.1 @100.1-.9 so Im pretty consistent. That was on pure 91 though. The other run was on a 91/100 blend for probally 94-95?

[ar design]

Hmmm MPH looks a little low even for up here.

[roninsoldier83]

Originally Posted by ar design

Hmmm MPH looks a little low even for up here.

I thought it was just fine actually (102.3mph on my first/only half decent pass), given the fact that it's an xi on 91 octane. I'm sure the RWD guys should be trapping around the ~104-105mph mark with just the flash, but I have 200-300 lbs on them & a larger drivetrain loss (at MAC, from the graphs I've seen, the RWD 335i guys seem to be putting down an extra 15+whp over the AWD 335xi's stock vs stock).

I know a couple of the local xi's are trapping 106-107mph up here, but they're also running full bolt-ons & meth haha. My car is otherwise stock. I'm betting on a cool evening, with a decent launch, I can probably coax 103-104mph traps out of her.

[ar design]

Oh oh oh, you are XI. My bad. Nevermind

Monday morning with no sleep FTL!