Like stories like this? You’ll see every article as soon as it's published by reading the print edition of Grassroots Motorsports. Subscribe now.
Story By Randy Pobst • Photos By photosbyjuha.com
ran my first autocross in 1977. Back then, a 10-second zero-to-60 run was pretty quick. Disco was so cool. There was no AIDS pandemic. No cell phones. No …
Always good to read articles by Pobst. Explains a lot about how my Supra handles. Low torque off boost, wide, sticky tires all around, all conspires to make for an interesting car to drive. Have to try to enter a corner with a healthy amount of trail braking to get the rear to rotate in, once you're near the apex, floor it.
Takes a bit for the turbo to spool, and by the nose is pointed where you need it, and boost is coming on hard. Makes for a good time, but I would love to see someone with more experience teach me a thing or ten on how to extract more speed from it.
That was a good read.
Funny, had professional coaching at my last track day and it sounded just like this article. He really pushed me to slow down, patience, patience, patience. Full brake pressure on threshold braking zones - I was, as Randy so eloquently put, Bob Costasfooting around. I always thought I was trail braking, but needed (and still need) more subtlety in my release of brake pressure and more patience getting on throttle.
The most Interesting thing for me was the notes on the difference between momentum and power cars.
accordionfolder said:The most Interesting thing for me was the notes on the difference between momentum and power cars.
What did you take from that? I was rather tired when I read it last night, so I'm probably missing something. I gathered, take it a bit easier on power cars because you don't HAVE to carry every last bit of speed through the corner, and will go faster if you're a bit conservative. Would love to hear your interpretation.
My confusion might also source from having one of each. Miata, obvious momentum car, and Supra, power car. Where the line blurs a bit is that I did a lot in order to make the Supra drive more like the Miata...
In reply to te72 :
Take a look at these videos:
Viper
https://youtu.be/_EDVNTcKRPs?t=1m14s
Miata
https://youtu.be/8TEHde-xkbk?t=1m30s
Same corner, check out the relative corner entry speeds of both (and how hard the miata is hitting it). Low speed corner you're having to wring a momentum car for all it's worth, in the power car you have to be patient and straighten out the corner as much as possible before giving it the beans.
Viper
https://youtu.be/_EDVNTcKRPs?t=32s
Miata
https://youtu.be/8TEHde-xkbk?t=25s
The Miata here is WOT up the hill, the Viper is tip-towing it up the hill compared to that. "Powerful cars in fast corners are driven just like low-output cars in slow corners." Not the best direct comparison, down force car on street tires, and a spec miata on slicks - best I could find easily.
I don't think that point was super clear in the article. Of course, this is just how I'm reading it/understand it, take it with a grain of salt.
Good stuff. My car only has a 6 speed, so I'm not sure I can use all 8 secrets though.
Armitage said:Good stuff. My car only has a 6 speed, so I'm not sure I can use all 8 secrets though.
I only have 5!?
In reply to accordionfolder :
So, takeaway for me sounds like, wait until it's pointed straight before flooring it in a powerful car. Makes sense, if you have great throttle response and a lot of torque all over the place. My car is a bit different though, it's pretty gutless off boost. Ever seen 80's F1? They had to get on the throttle SUPER early and time things just right or they either spun or lost time.
I think the part that's confusing me is the "low output cars in slow corners" idea. I'll freely admit I have minimal track time under my belt, and it's all been autocross or digital for me. In my Miata experience though, you can floor those things everywhere if they're stock. Almost have to... so to suggest that you keep the throttle pinned in a high output car in a fast corner seems a bit odd to me. Might just be how it's worded though, Randy's writing has gotten better over the years.
In reply to te72 :
I think you misunderstood what my interpretation was - that first set of videos is a lower speed corner (Road Atlanta 10a/b). The miata, to eek out a good lap time has to be right on the edge of the traction circle - i.e. Keeping it's momentum as high as possible. The Viper goes from 150+ -> 55mph for that turn (as Randy puts it's: "flat stop" for that corner) - for the Viper he's barely moving compared to the rest of the lap and relative speed - the Miata is flying around that corner compared to it's relative speed around track.
The second set of videos is the esses at Road Atlanta, a higher speed corner (downhill initially, pretty fast - videos don't illustrate it super well). The Miata (a momentum car) is flat out until braking for 5 because of lack of push. If you tried to be flat out without throttle control heading into the esses in the downhill section in a high power car, it'd get ugly. I.e. it's a bit scarier here in the power car, while the momentum car is just flat out.
That is:
A high speed corner in a momentum car is relatively calm - a high speed corner in a power car is a bit hairy
A low speed corner in a momentum car is NOT calm, you have to keep the momentum up - in a power car is (generally) super calm, you can't open up the taps until you've straightened out anyways.
Or that's what I took from the article. Those videos aren't perfect examples btw.
In reply to accordionfolder :
Ok, ok, that makes a lot more sense than before. I appreciate you clarifying. I tend to learn better by experiencing, than reading, always have.
I think that's what makes a momentum car fun though, even if you aren't ACTUALLY going very fast, you definitely feel like it because you have to wring the little thing out for all it's worth. Also your "That is: " explanation perfectly exemplifies why my Miata fees much faster at slower speeds than the Supra. It probably isn't, it's just that the Supra feels like you're putting around at anything less than 70mph.
Again, thanks for clarifying! =)
In reply to te72 :
Agree on both fronts, I learn best trying and making a mess of it!
When I was old enough to play on the race track lesson 1 was to auto cross. Then dad said autocrossing was hard on the car. Porsches do not go into first gear rolling. Time to go to the race track. 18th birthday present was a b&b race seat. Had to build seat mounts and a wrap around. Ass solid easier to drive.
accordionfolder said:In reply to te72 :
I think you misunderstood what my interpretation was - that first set of videos is a lower speed corner (Road Atlanta 10a/b). The miata, to eek out a good lap time has to be right on the edge of the traction circle - i.e. Keeping it's momentum as high as possible. The Viper goes from 150+ -> 55mph for that turn (as Randy puts it's: "flat stop" for that corner) - for the Viper he's barely moving compared to the rest of the lap and relative speed - the Miata is flying around that corner compared to it's relative speed around track.
The second set of videos is the esses at Road Atlanta, a higher speed corner (downhill initially, pretty fast - videos don't illustrate it super well). The Miata (a momentum car) is flat out until braking for 5 because of lack of push. If you tried to be flat out without throttle control heading into the esses in the downhill section in a high power car, it'd get ugly. I.e. it's a bit scarier here in the power car, while the momentum car is just flat out.
That is:
A high speed corner in a momentum car is relatively calm - a high speed corner in a power car is a bit hairy
A low speed corner in a momentum car is NOT calm, you have to keep the momentum up - in a power car is (generally) super calm, you can't open up the taps until you've straightened out anyways.
Or that's what I took from the article. Those videos aren't perfect examples btw.
Think about non-momentum cars that make a lot of torque (and sometimes horsepower) like older F-bodies and Mustangs. They are not momentum cars right? No, but they are non-momentum-preserving cars. They have to brake more and older, stockish ones don't have enough tire since they are heavy. When AXing my moderately modded IROC-Z, it still behooves me to drive it like a momentum car despite its strong torque numbers. Point and shoot remains a bad idea. Heavy cars! Torque can get me out of trouble, but it's still not nearly as good as smooth!
You'll need to log in to post.
