MPSC vs. Hoosier- Lateral Gs data
06-04-2006, 06:58 PM
#16
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
To get MPSCs to the right hot temps, I start out at 25-26 front and 28-29 rear, depending on ambient, then watch them the first couple of runs. Get them over 36psi and it is not fun!
06-04-2006, 07:22 PM
#17
Three Wheelin'
Join Date: May 2001
Location: Plano, TX
Posts: 1,620
Likes: 0
Received 0 Likes
on
0 Posts
I like to run the same pressure all the way around on my 993 c2. I run the Hoosiers at 38psi all the way around and the MPSC's at 34psi (both hot psi). I usually start the MPSC's at 23-25psi cold all the way around. My lap times with the Hoosiers are only a quarter to a half a second faster than the MPSC's. Now, I can get some of my fastest times on the MPSC's at the end of a 30 minute session, while the Hoosiers typically fall off after 20 minutes and I have to baby them to the end. Of course the Hoosiers start off much faster, I can typically get some of my fastest laps at the start.
As of note, I'm taking about the short Hoosier's (245/35 and 285/30's). I ran the tall Hoosier's ,(245/40 and 305/30's) which are about an inch longer in diameter than the shorties, for an enduro (1hour) and they faired pretty well. I guess the taller side walls keeps them cooler longer. It does lengthen the gearing but it was a nice trade off not skating at the end of the race.
George
As of note, I'm taking about the short Hoosier's (245/35 and 285/30's). I ran the tall Hoosier's ,(245/40 and 305/30's) which are about an inch longer in diameter than the shorties, for an enduro (1hour) and they faired pretty well. I guess the taller side walls keeps them cooler longer. It does lengthen the gearing but it was a nice trade off not skating at the end of the race.
George
06-04-2006, 10:17 PM
#19
Rennlist Member
My lap times with the Hoosiers are only a quarter to a half a second faster than the MPSC's. Now, I can get some of my fastest times on the MPSC's at the end of a 30 minute session, while the Hoosiers typically fall off after 20 minutes and I have to baby them to the end. Of course the Hoosiers start off much faster, I can typically get some of my fastest laps at the start.
George[/QUOTE]
George suspension is working well with minor adjustments car was slightly better on the old on real smooth track sections, but overall great. As you said Hoosiers fall off and I have told drivers new to them to look out for the "OH Sh*t" moment as they get greasy 20mins in on hot laps. Always happens to me on a bigger sweeper at the apex.
Car behind me always backs off as I correct a near spin. I think I can count 5 of these events over the last year or so. Only big benefits of the Hoosiers is immediate grip and you can start hot after a big scrub or two.
George[/QUOTE]
George suspension is working well with minor adjustments car was slightly better on the old on real smooth track sections, but overall great. As you said Hoosiers fall off and I have told drivers new to them to look out for the "OH Sh*t" moment as they get greasy 20mins in on hot laps. Always happens to me on a bigger sweeper at the apex.
Car behind me always backs off as I correct a near spin. I think I can count 5 of these events over the last year or so. Only big benefits of the Hoosiers is immediate grip and you can start hot after a big scrub or two.
06-04-2006, 10:38 PM
#20
Rennlist Member
Join Date: Aug 2003
Location: Naperville, IL
Posts: 387
Likes: 0
Received 0 Likes
on
0 Posts
I think the results, while useful, are dependent on the car as well. For example I know Hooisers actually like 3 degrees of camber, so at 2 you're not using them effectively. Perhaps the MPSC's just work better at two. I've pulled a "sustained" 1.49 G's in my car on Hoosiers, and could never come close to that reliably on the MPSCs. My car however is quite light and never generated decent heat in the MPSC's as a result.
The MPSC's ARE a harder compound, with "predictably" less grip.
The MPSC's ARE a harder compound, with "predictably" less grip.
06-04-2006, 11:35 PM
#21
Three Wheelin'
Join Date: May 2001
Location: Plano, TX
Posts: 1,620
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by bobt993
George suspension is working well with minor adjustments car was slightly better on the old on real smooth track sections, but overall great. As you said Hoosiers fall off and I have told drivers new to them to look out for the "OH Sh*t" moment as they get greasy 20mins in on hot laps. Always happens to me on a bigger sweeper at the apex. Car behind me always backs off as I correct a near spin. I think I can count 5 of these events over the last year or so. Only big benefits of the Hoosiers is immediate grip and you can start hot after a big scrub or two.
Car behind me always backs off as I correct a near spin. I think I can count 5 of these events over the last year or so. Only big benefits of the Hoosiers is immediate grip and you can start hot after a big scrub or two.You are right about the Hoosiers, I can on them hard right away. But then I don't like having to manage them at the end. I really do like the way I can push the MPSC's all the time. Hell, when I overcook a corner, they only stick better for the next one, while if you do the same with the Hoosiers, you have to manage the next two or three corners. BUT, since the start is so important in CR, I think I'm going to run sprints on the Hoosier from now on. Finally, since almost every person runs the Hoosiers in races, they have the same issues.
George
06-05-2006, 01:07 AM
#22
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Guys
Concerning the speed difference, I thought I mentioned earlier in the thread that I was running at a different pace and boost levels, it looks like I didn't
. This is why the top speed is different. One is at 0.7 Bar (MPSC) and the other at 0.9 Bar, one was a first time at the track for a DE, and the other was a practice lap for a sprint race.
Bob, thanks for the input..I thought that the Gs that I am showing with the MPSCs are very decent? They should be running at good pressure/temps? My problem is with MPSC cold on the street, not the track. My car has a lot of torque and I have datalogged over 0.4Gs of sideways movement at over 100mph under straight line acceleration, I loose traction easily even with the 315s. On the track, the MPSC "snap" more than the Hoosier, but this can be easily offset by smoother throttle application. As far as pressures FR and Rr, same pressure works best for my car setup, it was tested and calibrated endlessly by one of the top German racing teams and then tested at the 'Ring, it has had quite a few suspension mods done to it.
SundayDriver, thanks for the great input as usual.. This is a GPS+accelerometer based datalogger, so it does calculations and corrections both ways. A tilt of 10 degrees is spotted when you download your data and you get a warning. Later the tool calibrates accel and GPS together. It is a very sharp tool, albeit not a professional one. Since I am using it on the same track, same car and driver, the comparison for me is interesting as far as showing me that both tires are great, I expected the MPSC to have much lesser grip when compared to the R3S05, which does not seem to be the case?
There is a very slight banking at the turn where the data was measured. You are absolutely right when it comes to lap times being the best indicator, unfortunately I don't have comparative data under sprint conditions on both, I only use Hoosier. I will try to extract time based data instead of distance and try to smoothen out the curve..Thanks
Thanks for the excellent feedback, I do not intend to start a Gsum debate!
Concerning the speed difference, I thought I mentioned earlier in the thread that I was running at a different pace and boost levels, it looks like I didn't
. This is why the top speed is different. One is at 0.7 Bar (MPSC) and the other at 0.9 Bar, one was a first time at the track for a DE, and the other was a practice lap for a sprint race.Bob, thanks for the input..I thought that the Gs that I am showing with the MPSCs are very decent? They should be running at good pressure/temps? My problem is with MPSC cold on the street, not the track. My car has a lot of torque and I have datalogged over 0.4Gs of sideways movement at over 100mph under straight line acceleration, I loose traction easily even with the 315s. On the track, the MPSC "snap" more than the Hoosier, but this can be easily offset by smoother throttle application. As far as pressures FR and Rr, same pressure works best for my car setup, it was tested and calibrated endlessly by one of the top German racing teams and then tested at the 'Ring, it has had quite a few suspension mods done to it.
SundayDriver, thanks for the great input as usual.. This is a GPS+accelerometer based datalogger, so it does calculations and corrections both ways. A tilt of 10 degrees is spotted when you download your data and you get a warning. Later the tool calibrates accel and GPS together. It is a very sharp tool, albeit not a professional one. Since I am using it on the same track, same car and driver, the comparison for me is interesting as far as showing me that both tires are great, I expected the MPSC to have much lesser grip when compared to the R3S05, which does not seem to be the case?
There is a very slight banking at the turn where the data was measured. You are absolutely right when it comes to lap times being the best indicator, unfortunately I don't have comparative data under sprint conditions on both, I only use Hoosier. I will try to extract time based data instead of distance and try to smoothen out the curve..Thanks
Thanks for the excellent feedback, I do not intend to start a Gsum debate!
Last edited by Jean; 06-05-2006 at 04:06 AM. Reason: Corrections done
06-05-2006, 01:23 AM
#23
Addict
Rennlist Member
Rennlist Member
Join Date: Dec 2001
Location: SF bay area, CA
Posts: 2,094
Likes: 0
Received 0 Likes
on
0 Posts
nice comparison #s jean. it would be even more meaningful if you used the recommended hoosier settings of at least 3degrees -ve camber and higher pressures of at least 40psi. hoosier states that higher pressures will give you improved performance.
an optimum MPSC setup vs. optimum hoosier setup will more than likely show more of a performance difference.
just mentioning this because it doesn't look like you have addressed the hoosier setup yet... you just mentioned optimizing the MPSC at the "Ring"
an optimum MPSC setup vs. optimum hoosier setup will more than likely show more of a performance difference.
just mentioning this because it doesn't look like you have addressed the hoosier setup yet... you just mentioned optimizing the MPSC at the "Ring"
Originally Posted by Jean
Guys
Concerning the speed difference, I thought I mentioned earlier in the thread that I was running at a different pace and boost levels, it looks like I didn't. This is why the top speed is different. One is at 0.7 Bar (MPSC) and the other at 0.9 Bar, one was a first time at the track for a DE, and the other was a practice lap for a sprint race.
Bob, thanks for the input..I thought that the Gs that I am showing with the MPSCs are very decent? It must be that they are running at good pressure/temps? My problem is with MPSC cold on the street, not the track. My car has a lot of torque and I have datalogged over 0.4Gs of sideways movement at over 100mph under straight line acceleration, I loose traction easily even with the 315s. On the track, the MPSC "snap" more than the Hoosier, but this can be easily offset by smoother throttle application. As far as pressures FR and Rr, same pressure works best for my car setup, we have tested and calibrated endlessly with one of the top German racing teams at the 'Ring. My car has had quite a few suspension mods done to it.
SundayDriver, thanks for the great input as usual.. This is a GPS+accelerometer based datalogger, so it does calculations and corrections both ways. A tilt of 10 degrees is spotted when you download your data and you get a warning. Later the tool calibrates accel and GPS together. It is a very sharp tool, albeit not a professional one. Since I am using it on the same track, same car and driver, the comparison for me is interesting as far as showing me that both tires are great, I expected the MPSC to have much lesser grip when compared to the R3S05, which does not seem to be the case? There is a very slight banking at the turn where the data was measured.
Thanks for the excellent feedback, I do not intend to start a Gsum debate!
Concerning the speed difference, I thought I mentioned earlier in the thread that I was running at a different pace and boost levels, it looks like I didn't. This is why the top speed is different. One is at 0.7 Bar (MPSC) and the other at 0.9 Bar, one was a first time at the track for a DE, and the other was a practice lap for a sprint race.
Bob, thanks for the input..I thought that the Gs that I am showing with the MPSCs are very decent? It must be that they are running at good pressure/temps? My problem is with MPSC cold on the street, not the track. My car has a lot of torque and I have datalogged over 0.4Gs of sideways movement at over 100mph under straight line acceleration, I loose traction easily even with the 315s. On the track, the MPSC "snap" more than the Hoosier, but this can be easily offset by smoother throttle application. As far as pressures FR and Rr, same pressure works best for my car setup, we have tested and calibrated endlessly with one of the top German racing teams at the 'Ring. My car has had quite a few suspension mods done to it.
SundayDriver, thanks for the great input as usual.. This is a GPS+accelerometer based datalogger, so it does calculations and corrections both ways. A tilt of 10 degrees is spotted when you download your data and you get a warning. Later the tool calibrates accel and GPS together. It is a very sharp tool, albeit not a professional one. Since I am using it on the same track, same car and driver, the comparison for me is interesting as far as showing me that both tires are great, I expected the MPSC to have much lesser grip when compared to the R3S05, which does not seem to be the case? There is a very slight banking at the turn where the data was measured.
Thanks for the excellent feedback, I do not intend to start a Gsum debate!
06-05-2006, 02:06 AM
#24
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Originally Posted by karlooz
it would be even more meaningful if you used the recommended hoosier settings of at least 3degrees -ve camber and higher pressures of at least 40psi.
just mentioning this because it doesn't look like you have addressed the hoosier setup yet... you just mentioned optimizing the MPSC at the "Ring"
just mentioning this because it doesn't look like you have addressed the hoosier setup yet... you just mentioned optimizing the MPSC at the "Ring"
I mentioned Hoosier cold 34PSI, which is within the recommended range..I see 40-42 PSI when hot.
The problem is that I probably used too high a pressure for the MPSC rather. We see up to 180 degrees on our tires on this track.
Both tires will perform better with more camber I agree, but it is a street car.
I am impartial to both tires and use them both, I also have a set of P Corsa on another set of wheels, they are great street tires.
06-05-2006, 02:20 AM
#25
Addict
Rennlist Member
Rennlist Member
Join Date: Dec 2001
Location: SF bay area, CA
Posts: 2,094
Likes: 0
Received 0 Likes
on
0 Posts
ahhh gotcha. i misread your hoosier pressures. so you should be shooting for 32/36psi HOT on the MPSC and you should be getting better grip.
i have -3degrees/0.1 degrees toe in front and -2.5degrees/0.25degrees toe in rear and found that the MPSCs wear well on the street. the fronts hardly wear at all... as expected. my 996 sees split street duty with my land rover.
BTW, have you been taking pyrometer readings? i am curious to see what the temperature spread is with wide tires. i have read that with wide tires less camber is needed as the outside edge actually has less contact with a wheel with more camber.
i have -3degrees/0.1 degrees toe in front and -2.5degrees/0.25degrees toe in rear and found that the MPSCs wear well on the street. the fronts hardly wear at all... as expected. my 996 sees split street duty with my land rover.
BTW, have you been taking pyrometer readings? i am curious to see what the temperature spread is with wide tires. i have read that with wide tires less camber is needed as the outside edge actually has less contact with a wheel with more camber.
Originally Posted by Jean
Karlooz, thanks.
I mentioned Hoosier cold 34PSI, which is within the recommended range..I see 40-42 PSI when hot.
The problem is that I probably used too high a pressure for the MPSC rather. We see up to 180 degrees on our tires on this track.
Both tires will perform better with more camber I agree, but it is a street car.
I am impartial to both tires and use them both, I also have a set of P Corsa on another set of wheels, they are great street tires.
I mentioned Hoosier cold 34PSI, which is within the recommended range..I see 40-42 PSI when hot.
The problem is that I probably used too high a pressure for the MPSC rather. We see up to 180 degrees on our tires on this track.
Both tires will perform better with more camber I agree, but it is a street car.
I am impartial to both tires and use them both, I also have a set of P Corsa on another set of wheels, they are great street tires.
06-07-2006, 12:20 AM
#26
Rennlist Member
Join Date: Aug 2003
Location: Naperville, IL
Posts: 387
Likes: 0
Received 0 Likes
on
0 Posts
My experience with the MPSC's was so vastly different. I tried hot pressures from 28 up to 36 and never found them to grip well and they were unpredictable all the time.
I'll take the predictable degredation of the Hooisers over random snapping MPSC's any day.
I think the weight of the car they are on has LOT to do with how well these work.
I'll take the predictable degredation of the Hooisers over random snapping MPSC's any day.
I think the weight of the car they are on has LOT to do with how well these work.
06-07-2006, 12:32 AM
#27
Addict
Rennlist Member
Rennlist Member
Join Date: Dec 2001
Location: SF bay area, CA
Posts: 2,094
Likes: 0
Received 0 Likes
on
0 Posts
i've read several threads that came to the same conclusion. the MPSCs are great for cars >2800 lbs. your car is probably ~2200lbs. bonus for you is that the hoosiers will last longer.
Originally Posted by cstreit
My experience with the MPSC's was so vastly different. I tried hot pressures from 28 up to 36 and never found them to grip well and they were unpredictable all the time.
I'll take the predictable degredation of the Hooisers over random snapping MPSC's any day.
I think the weight of the car they are on has LOT to do with how well these work.
I'll take the predictable degredation of the Hooisers over random snapping MPSC's any day.
I think the weight of the car they are on has LOT to do with how well these work.
06-07-2006, 09:22 AM
#28
Lifetime Rennlist Member
Originally Posted by cstreit
My experience with the MPSC's was so vastly different. I tried hot pressures from 28 up to 36 and never found them to grip well and they were unpredictable all the time.
I'll take the predictable degredation of the Hooisers over random snapping MPSC's any day.
I think the weight of the car they are on has LOT to do with how well these work.
I'll take the predictable degredation of the Hooisers over random snapping MPSC's any day.
I think the weight of the car they are on has LOT to do with how well these work.
It is really challenging to get good tire temp data - you need both a good pyro and someone standing in the hot pits to take the readings, but it is well worth the effort.
06-07-2006, 09:56 AM
#29
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Originally Posted by SundayDriver
It is really challenging to get good tire temp data - you need both a good pyro and someone standing in the hot pits to take the readings, but it is well worth the effort.
It ends up with no consensus usually, with the Michelin experts saying something and the race engineers saying another. Inside of the tire first, no..middle, no...outside, or the opposite, or...do you start with the front right first, rear left, rear right ? left etc..? Most often they end up going with directional temps. I have seen this very closely with one of the Supercup teams, and they still manage to be the current world leaders
06-09-2006, 12:23 AM
#30
Rennlist Member
Join Date: Aug 2003
Location: Naperville, IL
Posts: 387
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by karlooz
i've read several threads that came to the same conclusion. the MPSCs are great for cars >2800 lbs. your car is probably ~2200lbs. bonus for you is that the hoosiers will last longer.
...and yeah, I heat cycle out Hoosiers well before they cord...