Hitting the drag strip this upcoming week end, have a cpl Q's

[B5Burn]

I am going to participate in our strip's Sport Compact day... apparently I get as many runs as we can fit in the day, about 40 competitors so far... head to heads in mixed classes but comparing slips at end of the day for prizes and whatnot. Able to do any tuning or match up with certain cars if we want to. Should be fun, a cpl other Euro's, plus a BUNCH of Subaru's and the usual crowd will be out.

My ride has big wheels. I DOUBT, although I have a cpl requests out, that I will be able to change this fact before this week-end. They're 19" Oettinger wheels and along with their Kumho Ecsta's - 235/35/19 adds up to about 52lbs per wheel. Heeaavvy.

So, I am not really racing for any competitive reasons... it's just for fun and hopefully a tweak here or there (hence my AFR thread). I doubt I will granny launch it, but I don't want to snap my axles with these steamroller wheels.

Any tips please?? I have years of autocross experience (in my GLI), but don't have tons of launching-this-car-hard experience. So, tire pressures, launching, shifting timing (I redline at 7k with a GT2876 giant AR)... race gas injected under boost via staged bank of injectors...

Thanks!,
Bill.

[Turn10]

Sick rims man and also try to get some 100 octane.

[B5Burn]

Thanks for the rims comment, I buy 110 in bulk

When she hits about 1 psi, a second injector bank shoots 104 for a nice kick in the pants.

[Euro-Tuner]

lower you tire pressure to 25 lbs

[mike-2ptzero]

lower you tire pressure to 25 lbs

What? He said he did not want to snap an axle and will be running heavy wheels. He should start with the tire presssure high(40psi) and then lower it to increase traction if he needs it. The higher pressure will allow him to spin those wheels much easier and its better to spin the tires then it is to bog and higher tire pressure will help on the top end which means higher trap speeds.

[B5Burn]

Thanks again, I assume some things I just have to figure out for myself, my car keeps building boost right through redline so I always want to keep it going... but get caught sometimes with the slow Tach.

Not going to do a 3000rpm clutch drop to launch, but we'll see what happens :)

[Don Supreme]

3000???? Try 6000 +

[B5Burn]

Hahahaha, sheeesh, typo! wrong row on the keypad

hehe.

[andyrew]

race gas injected under boost via staged bank of injectors...

Slow down there tiger.... You want to show/explain this one?

[Don Supreme]

Slow down there tiger.... You want to show/explain this one?

probably extra injectors in the intake mani runners controlled by a stand alone computer.

[B5Burn]

Yes, Don's got it. I have an extra injector in each intake runner, shooting the 104 from a trunk mounted tank.. controller to set when and how much.

This car was built back when you were just hearing of Neuspeed and TAP (Total Audi Perf)... "easier" ways (but still $$$) to get the power from our motors now, but this works awesome.

[Nebone]

What about the normal injectors; whats the flow of those?

If you had normal injectors spray required fuel at boost and then extra race fuel, it would just run pig rich so this race gas fuels only at boost? Would regular 93 octane gas on primary injectors still power the car at boost?

I like the idea behind it. Don't have to drain the tank to put regular fuel in. Do you still have a fuel pressure regulator?

Cars in europe and other places I believe run a seperate propane tank and can switch between gasoline and propane on the fly so this is the same concept.

[B5Burn]

The main injectors are green top, I can't remember what the flow is, the extra injectors are red tops.

The main injectors shoot 94 full-time, then once boost begins, the extra injectors begin firing the 104 (in ratio to the boost, so not at 100% all the time) simultaneously. My timing and other parameters are all coordinated for the combination of the 94+104 for max power.

[mike-2ptzero]

The main injectors are green top, I can't remember what the flow is, the extra injectors are red tops.

The main injectors shoot 94 full-time, then once boost begins, the extra injectors begin firing the 104 (in ratio to the boost, so not at 100% all the time) simultaneously. My timing and other parameters are all coordinated for the combination of the 94+104 for max power.

Most likely 440cc(green) and 310cc(red).


You didn't happen to buy this car used? There was a guy on AW that had a car just like this which he bought used, he also owned a stage 3 white A4.

[B5Burn]

Nope, not the same car. This was built by the friend I bought from (well, built by the shops he paid to build it in BC, that is)... drove it so little, which is why I got it with only 30,000kms on the clock.

I've known this car since it came off the lot.

There are quite a few SDS systems around. Just not so many built this aggressively.

[mike-2ptzero]

Nope, not the same car. This was built by the friend I bought from (well, built by the shops he paid to build it in BC, that is)... drove it so little, which is why I got it with only 30,000kms on the clock.

I've known this car since it came off the lot.

There are quite a few SDS systems around. Just not so many built this aggressively.

Any plans to upgrade to a 30r seeing that you are running a 2 liter?

[andyrew]

Trick stuff! Probably a lot of plumbing and custom tuning/work required for that one, but certainly very cool!!

Andrew

[B5Burn]

Any plans to upgrade to a 30r seeing that you are running a 2 liter?

Ohhh, absolutely!! I have to change out my GT2876 in a bad way. I have a massive .86 A/R, so, gobs of top end power that just wants to keep going after redline, but now that this car see's more street driving, I want to match the turbo better. She has seen some track time originally, so it was 1 first gear launch and then all high speed boost.

B.

[Don Supreme]

Any underhood pics or previous dyno / track numbers?

[sixfiveoh]

Wow. So wait, what's the benefit and/or difference of this over meth injection?

[mike-2ptzero]

Wow. So wait, what's the benefit and/or difference of this over meth injection?

Not the same thing. He is using 8 injectors in place of just running 1 set of larger injectors. People did that back when there weren't any high imp injectors larger then 440cc. Not an issue now.

[Nebone]

And you can always have racefuel in the tank.

[Euro-Tuner]

race fuel is a good idea even if you arent written for it, it will prevent detination.

[mike-2ptzero]

race fuel is a good idea even if you arent written for it, it will prevent detination.

Running to high of an octane can actually decrease power and you end up with misfires.

[B5Burn]

Any underhood pics or previous dyno / track numbers?

My motor isn't show-y.. but check the pics Rob took in his thread... plus check his stuff, it's awesome.
http://www.audizine.com/forum/showth...=228298&page=2

No dyno numbers in my possession.. it would be amazing if I could get a pull at one of the Minneapolis shops on the HIN week end coming up... no idea there though. The previous owner shared some paper numbers, and some runs he had... but nothing of substance, so, nothing. We'll see what happens after the week end. Just came from my mechanic, new bung installed. Time to tweak!

B.

[mike-2ptzero]

[B5Burn]

Or work some internetz majic (sorry, I am lazy) and there you go, haha, thanks Mike.

Just came home from a great rip tonight (don't you love the fall-season temps?), so tomorrow I am going to do some logging, new to me also.. should be 'fun'.

B.

[mike-2ptzero]

Or work some internetz majic (sorry, I am lazy) and there you go, haha, thanks Mike.

Just came home from a great rip tonight (don't you love the fall-season temps?), so tomorrow I am going to do some logging, new to me also.. should be 'fun'.

B.

Fall season temps? I wish, here in socal it is still hitting 100 during the day and right now at 4:40pm it is 90 degs.

[B5Burn]

It's a crispy 19C / 66F tonight :) Time for more driving.

[audi til I die]

My ride has big wheels. I DOUBT, although I have a cpl requests out, that I will be able to change this fact before this week-end. They're 19" Oettinger wheels and along with their Kumho Ecsta's - 235/35/19 adds up to about 52lbs per wheel. Heeaavvy.

I'm not too big into 19's on B5's but I gotta say those do look sexy. If you were near Chicago I'd lend you a set of 17' 19lb track rims. What clutch do you have to handle those launches?

[B5Burn]

I'm not too big into 19's on B5's but I gotta say those do look sexy. If you were near Chicago I'd lend you a set of 17' 19lb track rims. What clutch do you have to handle those launches?

Thanks!! and thanks!

The clutch is not OEM, but the PO forgot what brand is in it... I won't be shitting on it, I don't think.. it is strong and isn't slipping or anything (yet). Haha, may dig into a new SB sooner than later!

B.

[B5Burn]

Well, that was a blast. However, my tune was way off and being too rich was zapping my boost hard. So.. slow time, but I am feeling positive about doing A LOT better. I barely broke 12psi when I can hit 20's easy. Felt like I had NO boost. Pulled some numbers back and by end of day, this was the best I could do, ok for my first day, I guess, haha.

My highlight of the day is launching an A4 at 6000rpm slipped the clutch just enough to generate some wheel spin on my fat tires (bumped them to 40 as per Mike's tip).

I have some in car vid I'll upload soon.

60: 2.07
330: 6.25
ET @ 594: 8.98
1/8 ET: 9.58
1/8 MPH: 75.04
1000' ET: 14.73
1/4 ET: 14.73
1/4 MPH: 95.16

[djwimbo]

Sounds like you had fun.

14.7 on a 2876? How rich were you running and why?

[B5Burn]

Got in about 7 runs, tons of fun.

Well.. with the .86 AR on my turbo, 1st and 2nd are almost stepping stones to the power... not literally, there is good boost after 5k, but this car hits its stride in the top end of 3rd and into 4th (JUST as I am crossing the line). I feel like I could snap the needle if I just kept my foot planted through 5th. Excuses, excuses. Highway driving is a frikking blast in this car. I could feel the car accel slightly when I let off the gas at the end of the run....

Anyway, after doing some logging last week, I added a little fuel down low based on some readings I had and pushed the AFR a llllittle too rich. Completely zapped the low end and spool up. I didn't have any of my map printouts or a laptop with me, so I roughly pulled the curve down a little and the power started coming back.

I am positive I could be hitting 105mph+ or so based on some other test runs I have done.

B.

[djwimbo]

I don't know much at all about tuning, so I'm not sure what could be done w/o changing the A/R, but that looks like it might be part of the problem.

[B5Burn]

Oh yeah, I just wanted to drag so I could have fun and do some logging... if I could, I would be bolting a GT30somethingorother on by now. There are a handful of turbo's that match my displacement better for the driving I want to do.

I have been watching the 3071 vs 3076 threads... but just standing on the sidelines.

On the tuning side, I figured out a whole bunch from my runs, so I have already clawed back a bunch of power.. plus, SDS is awesome with working with me and my numbers.. so, next strip day will just be quicker :)

[B5Burn]

PS, is it just me or is the tach on our car a little slow??

[djwimbo]

Mine works fine. At least I can't complain.
My rev limiter is supposed to be at 6500, but I've gone past it a couple times on accident. The gauge seems to rather accurate when that has happened.

[SouRce4]

B5Burn what kind of rear bumper or lower valence is that? it looks pretty nice

[mike-2ptzero]

PS, is it just me or is the tach on our car a little slow??

Yes. The more power you make and the quicker the engine can rev up while in gear you will notice that the stock tach has a problem keeping up in the lower gears.


BTW your 1000 ft and 1/4 mile ET are the same.