Track forum general chit chat.

[///Mobbin]

I'm curious who all has replaced or considered replacing their factory VLSD with a clutch pack type unit?

A little light reading for those interested:
dogbone had an excellent write-up on his custom OS Giken unit here - LINK.

Then the driftflo thread is packed full of information - LINK.

One great benefit that may not immediately come to mind is greater stability under braking by having some lockup on deceleration. From what I have read a VLSD does not lock on decel. Then my interest is also in what a good setup might be for a car that is still a DD but might become a dedicated track car one day.

[Sapper_M3]

Originally Posted by Kong Sheng Han

Has anyone here done a chumpcar race? A group of friends and I are looking to do an enduro at COTA next year. Need advice on good, reliable car. Better to build a car or buy/rent a race prepped car?
Not requiring a comp license is good, in that I (we) don't have to go out and get licensed, but it's also bad because I'd be sharing the track with complete noobs. Make it work with a group of friends or join a team, either would be fine although racing with friends would be more fun.

I have a fair amount of experience racing budget endurance series (Chumpcar, World Racing League, Lucky Dog, 24 Hours of LeMons). PM me, and I'd definitely be willing to give you some tips, points, etc over the phone. I'm swamped all week with work, but I could give you a call this weekend sometime.

Just a heads up, though, I don't think you'll find yourself overprepared for Chumpcar because you've done HPDEs and track days. W2W racing is a completely different animal, and even lapping in Advanced groups (although doing this definitely gives you great fundamentals and a good base) doesn't make you a racer.

I've done around 15 endurance races now (mostly Chumpcar, but I've had a few WRL, LDR, and LeMons races) over the last 4 years, and I entered my first race with about 20 or so track days. I thought I was a pretty good driver. I was wrong. The fact that you don't "license" like SCCA and NASA doesn't mean much for driver experience levels or indicate anything about the level of competition. I'm a big fan of SCCA and NASA, but with a couple thousand dollars, you can get a Novice license in a weekend and after a couple races without hitting anyone you'll have a full competition license in most regions. Now, with that said, both SCCA and NASA licenses still show SOMETHING whereas technically anyone could race Chump. In practice, though, I haven't seen this to be an issue. In my 15 or so races, I haven't seen many drivers (although I'm sure some might be out there) with no track/HPDE experience, and the large majority (I don't have numbers of course, but this is my experience racing on over 10 tracks across the country from Pittsburgh to Seattle) have many more trackdays and races than I do. A significant portion of the population hold current SCCA/NASA licenses or previously held these licenses (this is probably because HAVING a racecar and gear is the biggest hurdle to Chump racing, and these guys already have cars).

Long story short, I went into my first race thinking HPDE/trackday experience would let me hold my own against at least PART of the racing field. I was dead wrong. The vast majority of guys out there will be racers, and they will race like racers. Even with a long history of Advanced group lapping, I'm willing to bet you'll be overwhelmed out there initially.

With ALL of that being said, I want to emphasize that I am ABSOLUTELY NOT discouraging you from joining up. I highly encourage it! W2W racing is a blast, and with your background (from what I've seen on the forum), this is a great next step for you. Just go into it with the right mindset (don't make the mistake, like I did, of thinking you'll be a hotshot out there), bring a well-sorted car, and have (if possible) teammates with driving experience. You'll have a lot of fun out there.

[roastbeef]

I would love to, but there is just so many other things that need to be done to the car before the differential needs to get modded. It's absolutely because of cost- I think there is a long list of things that should be done before a beginner driver like me starts making major changes like a differential.
I have to build my car slowly or else I would wind up broke, single, and in a lot of debt. In a way, I have really enjoyed this because I get to feel the difference each little part makes.

I have been tracking the car with the factory zcp suspension for a while now. I'm finally getting to the point where I can identify parts of each track where there is more to be desired and could benefit from some superior valving.
I just can't justify a $5k+ differential, when so many other things (including my skill) can get little tweaks.

[dparm]

Originally Posted by ///Mobbin

One great benefit that may not immediately come to mind is greater stability under braking by having some lockup on deceleration. From what I have read a VLSD does not lock on decel. Then my interest is also in what a good setup might be for a car that is still a DD but might become a dedicated track car one day.

That's correct, the OEM GKN unit does not lock under braking and that can make the rear feel a bit "nervous".

[roastbeef]

those of you with the essex ap cp5060 kit... what racing pads have you tried? i just burned through my first set (ferodo dsUNO) and might want to explore something new to see whats out there.

i'm going to have to do some research to see if the cobalt friction xr2 will fit my calipers. anyone else have a suggestion? i liked the dsUNO, but i have little experience with race pads and want to experiment a little bit and see if i'm missing out on anything.

[///Mobbin]

Originally Posted by roastbeef

those of you with the essex ap cp5060 kit... what racing pads have you tried? i just burned through my first set (ferodo dsUNO) and might want to explore something new to see whats out there.

i'm going to have to do some research to see if the cobalt friction xr2 will fit my calipers. anyone else have a suggestion? i liked the dsUNO, but i have little experience with race pads and want to experiment a little bit and see if i'm missing out on anything.

Are PFC or Pagid pads available in that shape? I liked using Pagid RS-29's on my last car. On PFC 08's now and likely going to PFC11's next. Advantage of PFC is that they don't need significant bedding.

[NoCarrier]

Originally Posted by roastbeef

Hit a 1:34:3 at big willow. Kinda meh, tires are spent already. Now I know the lifespan of an nt01.

One double day at Laguna
One day at big willow
Two days at auto club (one was an open track day)
1/2 day at big willow

Is this pretty typical? Seems like a lot of track time for such an aggressive tire. Have you done much suspension work on your car?

[ThunderMoose]

Originally Posted by ///Mobbin

I'm curious who all has replaced or considered replacing their factory VLSD with a clutch pack type unit?

A little light reading for those interested:
dogbone had an excellent write-up on his custom OS Giken unit here - LINK.

Then the driftflo thread is packed full of information - LINK.

One great benefit that may not immediately come to mind is greater stability under braking by having some lockup on deceleration. From what I have read a VLSD does not lock on decel. Then my interest is also in what a good setup might be for a car that is still a DD but might become a dedicated track car one day.

I always heard that you want a more open diff for braking to help with trail braking and more lockup for accelerating out of turns. I have no actual experience but just what I heard.

[roastbeef]

Originally Posted by NoCarrier

Is this pretty typical? Seems like a lot of track time for such an aggressive tire. Have you done much suspension work on your car?

This is the first time I have taken these tires to the cords. Laguna is kind to tires, but hard on brakes. Big willow is hard on tires, but easier on brakes. Auto club is kinda both. Maybe just a good balance of wear on my local tracks?

all i have are camber plates at -3 (i'm not 100% sure, but pretty sure) and solid subframe and diff bushings (helps the rear suspension work more efficiently). their contribution to tire wear may be minimal, but i also have thre fall line motorsports tension arm monoball conversion. oem zcp suspension.
i placed the tires with the most meat on the outside up front and the balder tires in the rear for my last big willow day. the tires still corded on the outside up front and on the inside in the rear anyways. flipping would have been a waste, i probably couldn't have even gotten another session out of them if i flipped them. all i did was place them appropriately based on wear for each specific track day. i don't rotate at lunch, i eat.

[redpriest]

Sticking with the DS1.11s, they work for me.

[roastbeef]

Got a cool little pin from attending that driving day. Adds ~5 hp.

[ayao]

Originally Posted by roastbeef

those of you with the essex ap cp5060 kit... what racing pads have you tried? i just burned through my first set (ferodo dsUNO) and might want to explore something new to see whats out there.

i'm going to have to do some research to see if the cobalt friction xr2 will fit my calipers. anyone else have a suggestion? i liked the dsUNO, but i have little experience with race pads and want to experiment a little bit and see if i'm missing out on anything.

A buddy of mine swears by his Raybestos ST-47s which I'm likely to try when I burn through my DS1.11s.

[roastbeef]

Originally Posted by ayao

A buddy of mine swears by his Raybestos ST-47s which I'm likely to try when I burn through my DS1.11s.

thanks, i'll have to give them a call. info on pad shapes is a bit vague on their site, but on summit, the most expensive pads from them are like $170.

[admranger]

Originally Posted by ///Mobbin

Are PFC or Pagid pads available in that shape? I liked using Pagid RS-29's on my last car. On PFC 08's now and likely going to PFC11's next. Advantage of PFC is that they don't need significant bedding.

I agree with Mobbin's recommendations. I'm a PFC whore. Love their pads and rotors. I just bite the pillow when I buy their $tuff.

[roastbeef]

My track buddy elim gave me his set of pfc08's for my oem rear brakes. I like them back there. Lots of people on here seem to be running them.

[ayao]

Originally Posted by roastbeef

thanks, i'll have to give them a call. info on pad shapes is a bit vague on their site, but on summit, the most expensive pads from them are like $170.

The porterfield website seemed to have some better fitment info on the raybestos pads. I think from the Essex website the raybestos fitment is # R2600.18 ... And when I priced them out it was $299 or so.

[roastbeef]

Originally Posted by ayao

The porterfield website seemed to have some better fitment info on the raybestos pads. I think from the Essex website the raybestos fitment is # R2600.18 ... And when I priced them out it was $299 or so.

Thanks, I must have missed them on the Essex site. This is the first I've heard of that company as well. Still $100 cheaper than the dsuno's.

I'm a little irritated that the dsuno's seemed to crumble towards the end of their life. There was a little more than 1/8" of pad material that just fell off of the backing plate when I took them out. Is this normal for racing pads? Damage from heat cycle?

[Kong Sheng Han]

Originally Posted by Sapper_M3

I have a fair amount of experience racing budget endurance series (Chumpcar, World Racing League, Lucky Dog, 24 Hours of LeMons). PM me, and I'd definitely be willing to give you some tips, points, etc over the phone. I'm swamped all week with work, but I could give you a call this weekend sometime.

Just a heads up, though, I don't think you'll find yourself overprepared for Chumpcar because you've done HPDEs and track days. W2W racing is a completely different animal, and even lapping in Advanced groups (although doing this definitely gives you great fundamentals and a good base) doesn't make you a racer.

I've done around 15 endurance races now (mostly Chumpcar, but I've had a few WRL, LDR, and LeMons races) over the last 4 years, and I entered my first race with about 20 or so track days. I thought I was a pretty good driver. I was wrong. The fact that you don't "license" like SCCA and NASA doesn't mean much for driver experience levels or indicate anything about the level of competition. I'm a big fan of SCCA and NASA, but with a couple thousand dollars, you can get a Novice license in a weekend and after a couple races without hitting anyone you'll have a full competition license in most regions. Now, with that said, both SCCA and NASA licenses still show SOMETHING whereas technically anyone could race Chump. In practice, though, I haven't seen this to be an issue. In my 15 or so races, I haven't seen many drivers (although I'm sure some might be out there) with no track/HPDE experience, and the large majority (I don't have numbers of course, but this is my experience racing on over 10 tracks across the country from Pittsburgh to Seattle) have many more trackdays and races than I do. A significant portion of the population hold current SCCA/NASA licenses or previously held these licenses (this is probably because HAVING a racecar and gear is the biggest hurdle to Chump racing, and these guys already have cars).

Long story short, I went into my first race thinking HPDE/trackday experience would let me hold my own against at least PART of the racing field. I was dead wrong. The vast majority of guys out there will be racers, and they will race like racers. Even with a long history of Advanced group lapping, I'm willing to bet you'll be overwhelmed out there initially.

With ALL of that being said, I want to emphasize that I am ABSOLUTELY NOT discouraging you from joining up. I highly encourage it! W2W racing is a blast, and with your background (from what I've seen on the forum), this is a great next step for you. Just go into it with the right mindset (don't make the mistake, like I did, of thinking you'll be a hotshot out there), bring a well-sorted car, and have (if possible) teammates with driving experience. You'll have a lot of fun out there.

Thanks for the offer. I'm also busy this week (ochem exam on Thurs ), but I should be available for a few hours Friday evening and likely all day Saturday. I might be busy on Sunday. I'll PM you when I get a chance.

What I was thinking when I typed "complete noobs" was that I think some people may not have the etiquette to move out of the way of a faster car, block a faster car, force people off the track, etc (I also understand that this happens with pros, too). It's good to have some feedback from you, as I have no idea what I'd expect in my first race. I believe I've done 11 track days FYI, so I'm not that experienced, and I don't think my driving is good enough. But I would like to enter a race within 2.5 years because I probably won't have time to do anything for 8 years after that due to med school and residency. Racing with little track time should be a humbling experience and a great learning tool. I'll leave my ego at home; I'd probably be pretty scared for the first few minutes of my stint.

I realized that making a team with friends won't work and would be too expensive, so I'm going to join a team. I know Winding Road Racing was at the Chumpcar race at COTA this year, so I'll ask them if they'll be racing next year too and if I can drive with them. The friend who has access to a SM is an instructor for NASA and does WRL enduros with the car. At the moment his team has three drivers, and I could be their fourth driver. I'll rent a racing suit and shoes and buy any other gear I'll need if I do end up racing with anyone.

I do question if I am fit for racing due to me being overly precautious about my spacing around other cars. In this video, at 2:30 I gave a car a point by and at that point, I thought I didn't have enough room to turn in and that I was kinda forced off track. I'm sure most people would've tucked in behind the car. I do tuck in close to a car that passes me, but "close" is to my standards. At 6:30, 10:30, and 11:40, I take a pass, and you can see how far out I get to create large spacing between my car and the other car. I doubt this is possible, or even appropriate, in W2W racing. At 13:10, I point someone by, and you can see how close he is to my car as he drives past. Passes like this make me very uncomfortable. I also don't get on people's asses as much as I have seen other drivers do when I ride with them. I think the closest I get is maybe a car length (I have bad depth perception). 2:10 in the second video is an example, although it does look like I'm more than a car length away.

Edit: You can see how close I'll get at 1:12.

[dogbone]

Originally Posted by ThunderMoose

I always heard that you want a more open diff for braking to help with trail braking and more lockup for accelerating out of turns. I have no actual experience but just what I heard.

A diff can be setup to lock on initial braking, but then still be open as you reduce braking forces and want to trail brake.

During initial braking, it is beneficial to have the diff lock and have the two rear wheels spin the same speed. Having the rear wheels spin the same speed encourages the car to go in a straight line. You want this on initial braking because it adds stability. I have said in the past that it feels like a parachute is slowing the car. But as you start thinking about getting into the corner, you want an open diff. A 1.5-way diff can be setup to give you exactly this behavior---locking on high-force initial braking and then open up when the braking load has reduced.

My diff is a 1.5-way diff and it acts like that. Someone linked to my super long diff posting above. The charts shown in that posting are from data collected by an AIM Solo DL in my car. There's no butt dyno there. It's hard data that shows my rear wheels lock nicely on pretty much every big brake press, but that on every corner entry, the wheels can spin their own speeds to efficiently get around every corner. The exception when the wheels don't spin the same speed on initial brake press is the Off-Ramp corner at Buttonwillow. That braking zone going into the corner is a mess---you wouldn't want the diff blindly locking there, and it doesn't.

[roastbeef]

just scooped up a gt4 lip. need to get rid of this wing asap! lowered the price to $400 picked up. will ship on your dime. link to FS thread;
http://www.m3post.com/forums/showthread.php?t=1313073

[redpriest]

Originally Posted by roastbeef

just scooped up a gt4 lip. need to get rid of this wing asap! lowered the price to $400 picked up. will ship on your dime. link to FS thread;
http://www.m3post.com/forums/showthread.php?t=1313073

I'm not quite sure I trust buying track parts from a cat with a scribbled on helmet.

[roastbeef]

but its a serious cat. serious track parts. you buy now.

girlfriend is going to be pissed when tires and a lip show up at the house. i have to at least tell her i sold one of the wings.