jake_zx2 PURSUIT OF A 8 MINUTE NURBURGRING LAP

Discussion in 'Corner Carver Racing Tech Discussion' started by jake_zx2, Dec 2, 2016.

  1. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    Hey guys! Name is Jake (in case you couldn't tell by the username). I moved to Germany in april 2016 shortly after buying my first mustang, a bone stock 2005 GT premium with only 35k miles, garage kept, only driven during warm months... even has the tires and brakes that came from factory.

    [PHOTOB][​IMG][PHOTOB]

    I've loved mustangs my whole life, but (somewhat controversially) never was a huge fan of drag racing. I don't see too much joy in going fast in a straight line for 10 seconds at a time. Road racing has always been more of a rush for me and requires more skill, dedication, and hard work to perfect. Therefore, my mustang will be built for a road corse rather than a straight line. I've been racing go-karts since a young age, and built my first car for autocross. it was a 2003 ford ZX2, and has about $9k invested in mods. The car was a great experience, taught me a lot about customizing cars, working with a goal in mind, and helped me adopt driving techniques to shave down my lap times. It's currently in storage back in the states, will be getting a turbo build once I move back.

    [PHOTOB][​IMG][/PHOTOB]

    An 8 minute Nurburgring lap time certainly is attainable. I have put down a 9:47, but my fastest recorded run is a 10:15 on my first ever lap. That being said, there are a few hurdles to overcome:
    ∙Needs to somewhat retain daily driveability. I say somewhat because my previous car was an EXTREMELY difficult daily. 2200 lb car + 10K coilovers + stripped interior - no A/C or PS = terrible daily driver, so I'm used to some pretty rough stuff
    ∙Needs to follow a budget. As a 20 year old with a low-ish income, gotta make sure I have money to pay the bills. Therefore, $2000 coilovers, $10,000 engine builds, etc. are out the window
    ∙reversibility. I plan on selling the car within the next couple years, and I plan on returning the car to stock before I sell it (yes, that means everything you see go on the car in this thread will be in another part-out thread in the future). therefore, everything I do have to have the ability to be reversed, or has to be subtle... as in no cutting vents into the hood, no crazy aero parts, and no big jobs that will result in an overly time-consiming tear-down.
    and, the big one...
    ∙needs to be in the low 8-minute mark at nurburgring with a *somewhat* inexperienced driver behind the wheel. I've never owned a RWD car before this, and though i've driven some pretty high HP RWD cars in the past, I've never had one on a track, nor have I ever really tried to push one through a corner.

    This thread will consist of my build, my track days/fast laps at all the tracks I attend while living in europe (with go-pro videos), and questions for the more experienced members in pursuit of my ultimate goal, a low-sub 8-minute nurburgring lap!

    Build won't actually begin until early spring, but the collection of parts has already begun! So far, I bought some *very lightly* used Eibach Pro Dampers, and some H&R Race springs. I also enheireted some low mileage 2013 GT brake calipers and rotors from a buddy who upgraded his and no longer had a use for the stockers. plans from here include:
    Brakes: Hawk pads, stainless brake lines, stop-tech slotted rotors, motul 600 fluid, cooling ducts
    Suspension: springs and dapers previously mentioned, Steeda Race panhard bar, poly bushings, 19x10 square wheels, 285-35 firestone firehawk indy 500 tires for starters. will determine need for control arms, strut bracing, etc. while testing on the 'Ring.
    Engine: Plan on keeping mostly stock. 300 HP should be sufficient, but if more power is needed, I'll adjust accordingly. Although, that discounted price on the Holley Sniper intake manifold IS pretty tempting...

    Let me know If you have any suggestions, and stay tuned for updates! If you would like to see my first Nurburgring lap, an autocross hot lap, or a stock 3v beating a 2001 Cobra in roll races, go check out my Youtube channel! https://www.youtube.com/channel/UC3FosILV2GXimWx3Iz8llkQ?disable_polymer=true


    ADMINS, if this is the wrong section for this thread, please relocate it. thank you!
     
    Last edited: Dec 2, 2016
  2. Norm Peterson

    Norm Peterson corner barstool sitter

    Age:
    70
    Posts:
    2,538
    Likes Received:
    14
    Joined:
    Feb 5, 2011
    Location:
    state of confusion
    Seat time in this car on that track.

    Datalogging, to help find places where you could have been going faster (it did seem to me that you were in 2nd more often than necessary, though perceiving the sharpness of curves from video is deceiving).

    No matter what your car's OE wheels/tires were, you'll need something better for any serious run at your goal. I'm thinking at least 285/xx (all around) on wheels no less than 10" wide, 295/xx on 10.5", 305/xx on 11's.


    Norm
     
  3. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    Norm,

    That's the plan! I have 3 laps around the ring so far, but it just got too sketchy on factory brakes and tires. But I'm starting to get used to the track. I'm going to look into getting some sort of datalogger to break my laps down into sectors and see where and when im faster or slower. The track is definitely deceptive, it looks FAR different in person than it does in any video game or youtube video. The hills are much taller, the turns are much sharper, and the track is far wider. The video I have posted was just a feeler lap... I didn't want to go 100% on my first lap ever. That may be why I was in second so often and kind of creeping through the turns. And yeah, in the OP, I stated my plans of switching to a 19x10 square setup with 285/35.

    Thanks for your input!
     
  4. Mach2burnout

    Mach2burnout 05 Redfire GT

    Posts:
    3,639
    Likes Received:
    0
    Joined:
    May 16, 2011
    Location:
    Central Louisiana
    Seat time, seat time and then some more seat time. Then start thinking about suspension mods. Tires and brakes first. Them one mod at a time. That way your not learning to drive a completely different car. Get used to the car and get comfortable before the next mod. JMO.


    Sent from my iPhone using Tapatalk
     
  5. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    I think what I'm going to do to familiarize myself with the track is find friends in different time brackets and follow them through the track to pace myself, progressively moving to the faster cars
     
  6. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    @mach2, I've determined that suspension is definitely needed, I just can't have the confidence I should have with the soft stock suspension. but I need to also get new brakes and tires before going again or else I probably won't make it through another lap! I don't think springs/dampers, wheels/tires, and brakes will be so drastic that I won't know the car... plus, luckily, there's an autoX event in april, which is right before I was planning on attacking the ring again... I'll use that to my advantage to try and familiarize myself with the car. From there, I think itll be good to go one step at a time, slowly moving to panhard bars vs watt's link, control arms, chassis and strut bracing, sway bars, etc.
     
  7. frank s

    frank s at Play

    Posts:
    508
    Likes Received:
    1
    Joined:
    Jul 25, 2010
    Location:
    Paradise
    "In this universe there are things
    that just don't yield to thinking
    —plain or fancy— Dude".
    —J. Spicoli, PolyPartyPerson

    It's a matter of doing. Imagination is marvelous, but never enough in a real-world skill environment.
     
  8. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    @frank Of course. But setting goals is never a bad thing! I think it's attainable with some seat time and some mods, but still a little optimistic. If nothing else, it'll just push me to do my best. It also helps that I've made friends with some amazing drivers who have been low 7s around the Ring and are willing to help me to get me where I need to be
     
  9. Thenorm

    Thenorm Autocrosser

    Posts:
    158
    Likes Received:
    1
    Joined:
    Mar 16, 2016
    personally i think it would be better to get all the mods done at once.

    get a feel for the "new" car, and then lots practice time with a car that doesnt change to be able to approach 10/10.

    when i bought my mustang, coming from a FWD Focus, i did all my planned mods right away. I only wanted to learn the car once.
     
  10. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    @thenorm Thats pretty much the plan... do all the major mods (springs, dampers, wheels, tires, brakes), learn the car, then adjust with tuning/more mods to correct oversteer, understeer, turn-in, etc.
     
  11. Norm Peterson

    Norm Peterson corner barstool sitter

    Age:
    70
    Posts:
    2,538
    Likes Received:
    14
    Joined:
    Feb 5, 2011
    Location:
    state of confusion
    Have you sat down and run any numbers at all to see what you're trying to accomplish here? While I don't know what the 'civilian driver' lap distance is, I think you're looking at making about a 15 mph increase in average speed. You're trying to match what Edmunds managed with an early 5th gen Camaro, which starts with about a hundred HP/hundred ft*lb advantage over what you've got available (albeit with somewhat heavier understeer in those earlier years). IOW, not impossible, but it's still looking like an uphill battle given that long straight at the end.

    I, too, disagree with the idea of making all mods at once - it's highly unlikely that you're going to make every choice in a manner that's optimum for you the first time, and in the unlikely case that your first choices do end up being close to optimum in the beginning they'll be less so later when the time improvements come in smaller increments.

    A couple of detail thoughts . . .

    Polyurethane bushings are not the hot tip for what you're out to achieve, at the very least not as the kind of no-brainer replacements in the rear suspension that works for the drag racers.

    I also wouldn't limit myself to 10" wide wheels, though there might be a lot of personal preference involved.
    My sig picture ↓↓↓ shows 285/35's on 18x11's, front and rear.


    Norm
     
    Last edited: Dec 2, 2016
  12. 2013DIBGT

    2013DIBGT I Hate Wheelhop

    Posts:
    331
    Likes Received:
    0
    Joined:
    Jun 3, 2013
    Location:
    The Ungreat North East
    I'm also a fan of doing all the mods at once. But with that said, going this route isn't so easy with a limited budget to start with.

    The chances are pretty high that you will be kicking yourself later for purchases you make now which were determined by your current budget. Ask me how I know :whistle1:

    The above sentence is mainly related to suspension mods and not with the "givens" such as wheels, tires and brakes which are a solid investment now that will carry forward later no matter which way you decide to go with the suspension components later.

    But with all that said, and if budget were not a concern, I strongly believe doing it all at once is better for the same reason mentioned by another poster. I would prefer to learn the car once in it's ideal state then waste time relearning it over and over again. Let's face it, it's barely acceptable to begin with in stock form in terms of handling so I don't see the benefit of learning how the car behaves while it's a hot mess.

    I do have to disagree with the OP on one thing though and that is the idea that the car won't be all that different after Suspension mods are done. If the right parts are chosen from the start it will be a totally different beast altogether afterwards.

    Good luck and I'm jealous of your back yard racetrack :clap:
     
  13. stevbd

    stevbd forum member

    Posts:
    76
    Likes Received:
    0
    Joined:
    Jun 24, 2016
    Jake, cool thread and nice driving.

    I'm no expert, but just my 2 cents: I would spend a little more on better dampers (Konis or Bilsteins) and tires (something decent in the max summer category). It just makes such a huge difference on these cars. You can save $$ for that by going to 18" rims, plus you'll save weight and have more tire options. Then with the brakes, by the time you buy new pads, stainless steel lines, stoptech rotors, cooling plates, and hoses, you're probably halfway or more to the cost of just upgrading to the 14" Ford brembo setup. That's $1100 and comes with everything including ss lines; it's a great deal and way better brakes than the '13 GT stockers.

    No matter what you decide it looks like you're on a good path. I enjoyed your video and look forward to following this thread.
     
  14. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    @Norm, I have not actually sat down and run any numbers, but like I said, I think it's fairly attainable, but perhaps a bit optimistic. As for the camaro, yes, it has a good bit more power, but also has at least 300 lbs over the mustang. with better suspension in the mustang, I can see it being pretty competitive. Plus, as far as civilian laps, or Touristenfahrten go, you count "Bridge to gantry" time... so basically, you're exclusing the long straight. time begins when you cross the bridge (see my video, white Bilstein overhang, @1:55) and ends when you cross gantry (red audi overhang, @12:10), so that should help me be around that camaro time slot. As for the mods, I personally like the idea of doing major mods first... that's the way I did it on my other car, just so I wouldnt have to constantly learn a new behavior. But I guess that all comes down to personal preference. Just out of curiousity, why do you say that about poly bushings? and what offset did you need to fit 11s in the front?? I thought that the widest we could fit up front was 10!

    @2013DIBGT, yeah, the budget is tough, but I don't really want to invest a whole lot of money into a car that I only plan on having for about 2 years. and I didn't mean that it wouldn't be different at all, I just just saying that it won't be completely beyond recognition, like transition from FWD to RWD. guess I worded that wrong lol. But thank you! I'm pretty excited to get rolling, all this cold weather needs to go away ASAP

    @stevbd Thanks! I would like to spend more money on dampers, but with how expensive Koni yellows are, after getting springs and caster/camber plates, I would be far better off just spending a bit more money and going with coilovers, which are pretty far out of the budget. But hey, if you know a good deal on some, send it my way! I'll be more than glad to get some for a low price! as for the tires, I'm going with the firestones because 1. they fall into my budget, and 2. my buddy (races an s2000) has them, and he loves them... says they arent the best daily tires becuase they're noisy and suck in the rain, but are the very best bang for your buck tire out there right now. As for the brakes, I was actually just looking into the brembos yesterday... I'm reallly considering picking some of them up instead.

    Thanks all for your input!
     
  15. fast Ed

    fast Ed forum member

    Posts:
    302
    Likes Received:
    3
    Joined:
    Nov 2, 2014
    Location:
    Caledon, Ontario CANADA!
    Seat time, 14" Brembos up front, good springs and shocks with an adjustable panhard bar, 10" wheels with 285s and a good differential will go a LONG way toward knocking down those lap times.


    cheers
    Ed
     
  16. Norm Peterson

    Norm Peterson corner barstool sitter

    Age:
    70
    Posts:
    2,538
    Likes Received:
    14
    Joined:
    Feb 5, 2011
    Location:
    state of confusion
    Here's where a track map of what you're specifically running and a good idea of its length would help. I can't tell from the many map hits that come up on a search which, and it's unlikely I'll ever get to see it in person.

    The wheels are Forgestars, which I got through Vorshlag, who developed the wheel specs and who are understandingly hesitant about specific offset information becoming widely available - if I even knew what they were. An ethical matter if I did.

    I do know that on smaller tracks - say, 2.25 miles and shorter - that a lightly modified 4.6L S197 can keep pace with any early (stock) 5th gen Camaro (the later FE4-suspended Camaros and the 1LE in particular would be a different story, but would have faster 'ring times as well). As long as the driver does his part.

    On polyurethane bushings, the problem is that while they permit free rotation about an axis running straight down the middle of the attachment bolt, they resist rotation about any other axis, sometimes with considerable force depending on geometry specifics. Since suspension components move in arcs (3-D arcs, actually), off-axis rotations cannot be avoided. These forces come from having to squeeze/squish/compress the much stiffer poly material in the same ways that the soft OE rubber accommodates without generating such large forces.

    Ultimately, those forces behave as additional roll stiffness, without being tune-able like an adjustable sta-bar is. And they can add nearly as much roll resistance as a small to medium rear sta-bar. Poly bushings can be themselves modified to some benefit, but you're going to be better off minimizing this sort of "binding" from the get-go and losing poly's 'stiction' on at least one end of every link (LCAs, UCA, PHB).

    Sometimes what you discover along your test-tune-retest-retune path is that you've ended up limited by one of your earlier choices. Either it has no adjustment, or not enough. Your tolerance for pitch and roll motions may change, maybe you don't have to base as much of your tuning into minimizing those, or maybe roll is OK but pitch/nose dive isn't. You probably don't know that yet.

    Before I even started the process of buying my '08, I thought I had everything figured out with respect to future mods for a serious corner-carver of a car, my own automotive preferences being much like yours since about . . . forever. So I did a lot of investigating of what was available - springs, sta-bars, shocks/struts, most everything - with an eye toward what I should expect as a result (I might have had an advantage here, being a 60 y/o engineer with a little DIY-level chassis experience at the time). And then I put that whole mod program on hold save for a little tire pressure tuning and let the car start telling me what it needed instead of it being me telling it what it was going to get.


    Norm
     
    Last edited: Dec 3, 2016
  17. frank s

    frank s at Play

    Posts:
    508
    Likes Received:
    1
    Joined:
    Jul 25, 2010
    Location:
    Paradise
    If Steeda supplies poly bushings with their appliances, I should try using the OE rubber instead? Or maybe try to introduce some voids in the poly bushings?

    At what level of dual-purpose adaptation does the binding of poly bushings become significant? On my 2009 GT/CS, Koni yellows, FRPP "p" springs, 26mm rear stabilizer, Steeda adjustable front bar, it seemed to me the "squishability" in the front link attachment would accomodate a bit of off-axis stress. The rear bar had poly where it pivoted in the body links, rubber at the body end of the links. Seemed to work well on both road and track, but wasn't really tested with full-on sticky rubber.
     
  18. jake_zx2

    jake_zx2 forum member

    Posts:
    68
    Likes Received:
    1
    Joined:
    Apr 28, 2016
    Here is my best attempt at a track map:

    [PHOTOB[​IMG][/PHOTOB]

    The red parts are parts that aren't driven. Bridge to gantry is 11.87 miles, and is usually about 35 seconds faster than a full lap.

    So, would it be fair to say that poly bushings essentially sacrifice mechanical grip in favor of responsiveness? I probably won't do poly bushings right away, but what would you suggest that I do if I find a need for control arms, sway bars, etc. that already come with poly bushings? replace them with OE? As far as pitch/roll/nose dive/etc, You're right, I'm not completely sure what all I would like to minimize yet... I know the nose dive is awful, the body roll is SOMEWHAT tolerable, but isn't remotely confidence inspiring, which in turn costs me time.

    As for wheels, I've been throwing around the idea of having daily wheels with all seasons (in Germany, if you don't have all-seasons, you're legally required to switch to winter tires from October to march) and track wheels (probably 19x11 if I can fit them) with performance tires. Anyone have suggestions for fairly cheap (no Super Sports... they typically run around $400 a tire) street-legal performance tires? Or, if the inconvenience of swapping wheels at the track doesn't outweigh the performance benefits, maybe some full-on race tires?
     
  19. Norm Peterson

    Norm Peterson corner barstool sitter

    Age:
    70
    Posts:
    2,538
    Likes Received:
    14
    Joined:
    Feb 5, 2011
    Location:
    state of confusion
    I've taken the "voided bushings" approach more than once, which has also included reshaping the flat faces into very flat cones allowing the control arm to rotate a little further before the flatness of the faces and the lack of anywhere for the squished poly to squish into starts getting in the way.

    On the poly/spherical Currie units that are on my car currently, I also opened up the hole in the poly so that the sleeves (ferrules) rotate with less stiction.

    In any event, the sleeves need to be no shorter than the poly so that all of the bolt torque goes into clamping the fixed parts in the joint. You should not be wasting any torque compressing poly, else you run the risk of a clunk.


    My take - if you can tell the difference of one adjustment hole on most adjustable rear bars, you'd easily notice the handling difference between poly bushings installed "straight out of the box" and after a good DIY mod.

    But a better and probably simpler test to prove to yourself would be to do a 'before and after' run across something like a smooth drainage gutter at an angle. This puts the suspension into 'roll' as well as 'bump', and the difference in firmness (and lateral head-toss) is clearly noticeable even if you aren't plugged into the handling side of things.

    For numbers, MM did a study some years ago and found that at least on some suspensions, all poly in the LCAs and no other bushing mods elsewhere could be adding 50 lb/in or more to the wheel rate in roll. Which is fine for a drag racer, who'd want more rear roll stiffness to help re-plant his RR tire under hard acceleration. Not so good for those of us who'd rather have their 1g and up fun happen around corners.


    Norm
     
  20. Norm Peterson

    Norm Peterson corner barstool sitter

    Age:
    70
    Posts:
    2,538
    Likes Received:
    14
    Joined:
    Feb 5, 2011
    Location:
    state of confusion
    Jake - what we want from control arm end details is accuracy of suspension motion, without any force downsides. In theory, that means rigid frictionless sphericals at both ends of everything that moves back there. But that's not exactly suitable for unlimited/unrestricted street use, and at least in the S197 chassis for the rear LCAs you can get close with a spherical at one end combined with a (possibly modified) poly bushing in the other. As a factory example, I think Whiteline does some bushing shaping specifically to reduce "binding".

    I'll have to study the map a little.


    On edit, the situation at the UCA is enough different from the LCAs that plain poly may not be capable of providing sufficient articulation for the kind of driving necessary for a hero lap at the 'ring that's free of major seat-pucker moments.


    Norm
     
    Last edited: Dec 4, 2016

Share This Page