Holbert race car gets 305s up front with no body work (kind of)
#61
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It didnt look that hard for you at all
Maybe it was hard for the turbo. He was working hard to keep you from getting by!
what i was talking about was just a little earlier apex on those first few turns to scrub speed and help with the lack of grip. if you watch my laguna footage, its like turn 3 or 4 in principle. many try and take a lat apex and its just too hard to get the car to turn down to apex and causes understeer and then oversteer. its hard to tell a lot from the video i know, but those are the things that stuck out to me.
mk
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what i was talking about was just a little earlier apex on those first few turns to scrub speed and help with the lack of grip. if you watch my laguna footage, its like turn 3 or 4 in principle. many try and take a lat apex and its just too hard to get the car to turn down to apex and causes understeer and then oversteer. its hard to tell a lot from the video i know, but those are the things that stuck out to me.
mk
Thanks Mark. It was a hard day at the office with the track pretty greasy. You had to wait quite a while before being able to re-apply power. The 2nd turn leading to under the bridge is beyond 90 degrees and that's why people tend to take it very late. If I took it much earlier I'd get thrown out too wide onto the marbles. As it is I was getting close as observed. The turn leading onto the bridge is really bad. You can't tell much in the video but it is really bumpy and I'm inbetween gears. Although 2nd feels better I will stick with 3rd the next time. As for the hands, must be the angle of the camera? They're on there all the time except for gear changes. I don't always keep them at 10 and 2 though. I sometimes have to brace myself in the seat and the hands get involved moving on the wheel, but I will sort that out.
thanks for watching.
Patrick
thanks for watching.
Patrick
#62
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I watched those videos Mark. Crikey that's a handful!! You seem to get push-tire squeal on all of them, but the last is definitely the worst. What suspension setup are you using, or allowed to use? Looks pretty firm and unyielding or unforgiving. Not that you don't do well with what you've got and it does look like a bit of fun. Talk about keeping your hands on the wheel. See you one handed tooling around like Karl Malden in the streets of San Fran there on some corners
. Actually I let go of the wheel sometimes and catch it when it flicks back. It's quicker than turning it by hand. I know that's not textbook but there was a famous Porsche test driver and journalist who did that famously. I just have a mental block with his name. Not Paul Frere, but of that level.
Anyway, I'll look forward to some new video with the wider fronts on to see what happens. Any idea when that may be?
Patrick
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Anyway, I'll look forward to some new video with the wider fronts on to see what happens. Any idea when that may be?
Patrick
#63
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It didnt look that hard for you at all
Maybe it was hard for the turbo. He was working hard to keep you from getting by!
what i was talking about was just a little earlier apex on those first few turns to scrub speed and help with the lack of grip. if you watch my laguna footage, its like turn 3 or 4 in principle. many try and take a lat apex and its just too hard to get the car to turn down to apex and causes understeer and then oversteer. its hard to tell a lot from the video i know, but those are the things that stuck out to me.
mk
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
what i was talking about was just a little earlier apex on those first few turns to scrub speed and help with the lack of grip. if you watch my laguna footage, its like turn 3 or 4 in principle. many try and take a lat apex and its just too hard to get the car to turn down to apex and causes understeer and then oversteer. its hard to tell a lot from the video i know, but those are the things that stuck out to me.
mk
Oh, and yes that event was a bit different than normal. 2 by 2 dragging off down the straight to head into 5 sprint laps. I hope we keep that format next season.
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#64
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Oh, btw Mark, can you post a couple more pics of your new fender mod to get that rubber underneath. Specifically I'm wondering what it looks like from the front going rearwards? Just to see the panel gap. I might contemplate doing the same with the new 10" wheels on the front.
tia
tia
#65
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I posted the video with the new tires on this post at the exhibition race at Thunderhill. It was surprisingly the same. Race had the bigger tires (305s) and the practice/open session was with normal 275s. Here is the link:
http://www.youtube.com/watch?v=qGqSJkmCyb0
As far as hands go, it really about position, not if one hand is on the wheel or not. (although it is best to have both on as much as possible) obviously, my car has enough power steering to drive it pretty easily with one, but generally, i have a shifter issue, where i have to preload the shift lever before shift. (broken, cracked at the lever pivot giving extra slop) The hands being left at the 10:00 postion is critical for best control (vs shuffle sterring or moving them on the wheel, unless you are autocrossing or full lock
)
Actually, the suspension is very soft, with the swaybars on stiff. probably the softest race car you will ever bounce the fenders on without question. Laguna induce push for most all cars, even CART/Champ cars. But, the second video was real bad. a lower wing setting, hood vent and splitter mod fixed that and its where the suspension is set at now. The reason for the 305 is to increase cornering speed which seems to be limiting it now through the 80mph sweepers.
As far as your video, as I mentioned, a couple of those first turns are like some of the ones we have hear in California. sometimes an earlier apex, with a trail brake turn in can help you around the turn, vs a traditional late brake, late apex turn in. Just a style change that can help on some turns. (Turn 3 after the tire bridge, for example. earlier turn in, would give you the ability to get on the gas ealier and let the car run out all the way to the birm for a lot more exit speed) Obviously, just going off what i see on the video, and looking at it as if i was in the car. Again, it doesnt look like your car is pushing that much, but the bigger front tires would certainly help with a little more bite up front. certainly under braking as I saw being the biggest difference.
mk
http://www.youtube.com/watch?v=qGqSJkmCyb0
As far as hands go, it really about position, not if one hand is on the wheel or not. (although it is best to have both on as much as possible) obviously, my car has enough power steering to drive it pretty easily with one, but generally, i have a shifter issue, where i have to preload the shift lever before shift. (broken, cracked at the lever pivot giving extra slop) The hands being left at the 10:00 postion is critical for best control (vs shuffle sterring or moving them on the wheel, unless you are autocrossing or full lock
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Actually, the suspension is very soft, with the swaybars on stiff. probably the softest race car you will ever bounce the fenders on without question. Laguna induce push for most all cars, even CART/Champ cars. But, the second video was real bad. a lower wing setting, hood vent and splitter mod fixed that and its where the suspension is set at now. The reason for the 305 is to increase cornering speed which seems to be limiting it now through the 80mph sweepers.
As far as your video, as I mentioned, a couple of those first turns are like some of the ones we have hear in California. sometimes an earlier apex, with a trail brake turn in can help you around the turn, vs a traditional late brake, late apex turn in. Just a style change that can help on some turns. (Turn 3 after the tire bridge, for example. earlier turn in, would give you the ability to get on the gas ealier and let the car run out all the way to the birm for a lot more exit speed) Obviously, just going off what i see on the video, and looking at it as if i was in the car. Again, it doesnt look like your car is pushing that much, but the bigger front tires would certainly help with a little more bite up front. certainly under braking as I saw being the biggest difference.
mk
I watched those videos Mark. Crikey that's a handful!! You seem to get push-tire squeal on all of them, but the last is definitely the worst. What suspension setup are you using, or allowed to use? Looks pretty firm and unyielding or unforgiving. Not that you don't do well with what you've got and it does look like a bit of fun. Talk about keeping your hands on the wheel. See you one handed tooling around like Karl Malden in the streets of San Fran there on some corners
. Actually I let go of the wheel sometimes and catch it when it flicks back. It's quicker than turning it by hand. I know that's not textbook but there was a famous Porsche test driver and journalist who did that famously. I just have a mental block with his name. Not Paul Frere, but of that level.
Anyway, I'll look forward to some new video with the wider fronts on to see what happens. Any idea when that may be?
Patrick
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Anyway, I'll look forward to some new video with the wider fronts on to see what happens. Any idea when that may be?
Patrick
Last edited by mark kibort; 12-06-2008 at 02:29 PM.
#66
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There is a picture at the beginning of this thread where you can see the hood line. it looks like an american car gap now.
I didt touch the fenders where it attaches to the bumper area. ironically, moving the fender out there, pinches the fender down on the tire. the rear bottom moves the fender out.
mk
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mk
Oh, btw Mark, can you post a couple more pics of your new fender mod to get that rubber underneath. Specifically I'm wondering what it looks like from the front going rearwards? Just to see the panel gap. I might contemplate doing the same with the new 10" wheels on the front.
tia
tia
#67
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It's cool to run these videos simultaneously in small screen mode and see the differences.
With the big motor, you're grabbing 4th gear way earlier on the long straight than with the stock motor. How does that figure into the whole HP/Gear ratio nexus?![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
With the big motor, you're grabbing 4th gear way earlier on the long straight than with the stock motor. How does that figure into the whole HP/Gear ratio nexus?
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Laguna race (new motor) with little push 1:38 lap time
http://www.youtube.com/watch?v=zxImi48nv-A
That is a little unfair, so this a laguna race in June 08 without the new motor to compare below
Laguna no push 1:39.0 lap time
http://www.youtube.com/watch?v=WvH6Yh540eE
Laguna race with big push 1:39.0 lap time
http://www.youtube.com/watch?v=GRG6Y791iBE
http://www.youtube.com/watch?v=zxImi48nv-A
That is a little unfair, so this a laguna race in June 08 without the new motor to compare below
Laguna no push 1:39.0 lap time
http://www.youtube.com/watch?v=WvH6Yh540eE
Laguna race with big push 1:39.0 lap time
http://www.youtube.com/watch?v=GRG6Y791iBE
#68
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I couldnt believe how much earlier im shifting into 4th. now, i get into the meat of 4th which is much much better for the entire hp utilization nexus. ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
At thunderhill i get way into the meat of 4th getting up to near 135 on the main straight , where before, i was at a little disadvantage for a few seconds in 4th with the smaller motor. all the other turns are fine, i just get closer to redline on most of the critical ones.
mk
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At thunderhill i get way into the meat of 4th getting up to near 135 on the main straight , where before, i was at a little disadvantage for a few seconds in 4th with the smaller motor. all the other turns are fine, i just get closer to redline on most of the critical ones.
mk
#69
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Here are some new shots with the fender moved out a little. no rubbing.
mk
mk
Oh, btw Mark, can you post a couple more pics of your new fender mod to get that rubber underneath. Specifically I'm wondering what it looks like from the front going rearwards? Just to see the panel gap. I might contemplate doing the same with the new 10" wheels on the front.
tia
tia
#70
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On my test run, the tires still hit the top of the fenders, but not by very much and only under extreme dips in the road at high speed. Im thinking they will hit and rub down the corkscrew and thats about it. unless i have a way to lift or push the fender out even farther. since this track day, Ive made this opening at the door fender area much larger. Im thinking of putting some slats there to make it look like its supposed to be there. (very GTR944 'ish)
on my fender cam video into the hills, you can see the tire impact the top of the fender and distort it. but its only for a fraction of a second , and the good news is that there is deflection and no force on the tire. Might be ok. Ill continue moving the fender out and up if possible to avoid tire fender contact. I think it will be worth it to have the big meats up front.
might not look the best, but it is returnable, and does work (or seems to work)
with the 305s.
Mk
on my fender cam video into the hills, you can see the tire impact the top of the fender and distort it. but its only for a fraction of a second , and the good news is that there is deflection and no force on the tire. Might be ok. Ill continue moving the fender out and up if possible to avoid tire fender contact. I think it will be worth it to have the big meats up front.
might not look the best, but it is returnable, and does work (or seems to work)
with the 305s.
Mk
Here are the pics.
the passenger side had no real issues, and it was the outside tire for most of the turns, but there is a "corkscrew" like turn that compressed the driver side and it hit the top of the fender and burned the paint. on the driver side, i have my old injury from rubbing with the S2000 in a race 2 years ago. that might be why its rubbing, but its very close. I might be able to move it out more, but the hitting up in the fender is a worry. Laguna would crush the suspension and make this issue a real problem.
Bottomline, the difference was not as great as i had hoped. my laps times were the same and the car felt actually more turney with the smaller tires up front (275s) it could be due to the 305s pinched on too narrow of a rim, or the front now .5" higher (tires are 1" taller). car still pushed, and actually it felt like it pushed more! the contact patch might be the same as from the wear patterns, it looked like at least 1" of the outside tread wasnt even used.
mk
the passenger side had no real issues, and it was the outside tire for most of the turns, but there is a "corkscrew" like turn that compressed the driver side and it hit the top of the fender and burned the paint. on the driver side, i have my old injury from rubbing with the S2000 in a race 2 years ago. that might be why its rubbing, but its very close. I might be able to move it out more, but the hitting up in the fender is a worry. Laguna would crush the suspension and make this issue a real problem.
Bottomline, the difference was not as great as i had hoped. my laps times were the same and the car felt actually more turney with the smaller tires up front (275s) it could be due to the 305s pinched on too narrow of a rim, or the front now .5" higher (tires are 1" taller). car still pushed, and actually it felt like it pushed more! the contact patch might be the same as from the wear patterns, it looked like at least 1" of the outside tread wasnt even used.
mk
#71
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Here is a pic after today's moutain run. brakes are great, tires almost fit now. Just a few mm more and I should be home free.
This is a picture for Iceman because he wanted to know how low I was in front. This is fully settled at 112mm, with the 275s is more like 108mm.
mk
This is a picture for Iceman because he wanted to know how low I was in front. This is fully settled at 112mm, with the 275s is more like 108mm.
mk
#72
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Here is a pic after today's moutain run. brakes are great, tires almost fit now. Just a few mm more and I should be home free.
This is a picture for Iceman because he wanted to know how low I was in front. This is fully settled at 112mm, with the 275s is more like 108mm.
mk
This is a picture for Iceman because he wanted to know how low I was in front. This is fully settled at 112mm, with the 275s is more like 108mm.
mk
Okay I see now......how secure is the fender? It looks pretty loose at the bottom near the door? Or did you just make some extended mounts to hold it?
My 295-30 R888's are on now....alignment and corner balancing tomorrow!!
#73
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Its very secure. Its bolted up front, and at the rear portion to the chassis. Ive made a vent too, so that the fenderwell air can escape there. ( I dont know much about the air flow in the wheel well, but Ive heard that it can be vented like the 944GTR and other racer cars
) I might close off the bottom if this design works to fit those 305s up front. The best part of this is that, it can be returned to stock with the loosening of 2 bolts in a few minutes.
mk
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mk
#74
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Interesting, looks like Porsche copied my radical changes for '09 ![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
Im sure mine cost a lot less to make.
mk
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Im sure mine cost a lot less to make.
mk
Here is a pic after today's moutain run. brakes are great, tires almost fit now. Just a few mm more and I should be home free.
This is a picture for Iceman because he wanted to know how low I was in front. This is fully settled at 112mm, with the 275s is more like 108mm.
mk
This is a picture for Iceman because he wanted to know how low I was in front. This is fully settled at 112mm, with the 275s is more like 108mm.
mk
#75
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Hey Mark, I just happened upon this thread again while trying to sort out my new wheels and tires. So are you running the 305s on 10" wheels? I know that some tires are quite different in size to other brands or even models within the same brand, but I would have thought that 305s are just going to bulge excessively on a 10" rim? See some pics we took on the weekend. I was trial fitting some tires to my new 10" Enkeis and we got a Pirelli Corsa Nero 295/30 R spec on and under the guard. Not much room on the inside but you only need just enough. Then we tried a 285/30 Falken slick that had a larger OD and much squarer shoulders. It gave us more room re the coil but got pretty cosy with the front of the guard. In these pics we are not running any neg yet so once we knock it in about 3 degrees we will have enough clearance. I am going to give slicks a go first. If they wear out too quickly I will revert to R spec or DOTs. I have been communicating with quite a few people who also concur with your thoughts of running as much rubber on the front as possible. This counts for both 928s and modded 951s.
I would think if I can fit a 295 up front with no mods to the bodywork you 928'ers can do at least that if not more. Offset 60mm.
I would think if I can fit a 295 up front with no mods to the bodywork you 928'ers can do at least that if not more. Offset 60mm.