i thought the federal fz-201 isn't available in the US yet?
What is next in making my car faster?
- Thread starter TURBO2GO
- Start date
don't give me anything.......btw what are your dates?
Dave, where do you see a rating of 1477 load for either of the sizes you referenced - perhaps I am missing something in the less than professional pdf file they have posted. The 215/40/17 has a load of 83 (ie 1074 lbs) and the 255/35/18 has a load of 90 (ie 1323 lbs). The size 215/40/17 is an odd size when it comes to loads.
The best way to describe the impact of load is peculiarly what Steve Matchett of F1 fame/engineer and one Nascar reporter explained during Brickyard 400 this weekend (the latter re stiffness of sidewalls and impact on roll). Assume that the NSX has a weight balance of 49% front to 51% rear. At the track coming from a high speed straight into a tight turn, what will happen when you brake hard to take the turn (not dragging the brake)? The weight transfer will load the front (can't say by how much more but surely more than 50% balance) - and yes the upgraded suspension will try to minimize this weight transfer load. A tire that can handle higher weight load say 87 (1201 lbs) is preferable in my opinion to a tire that has a limit of 1074 lbs.
The OEM Bridgestones RE040 on 17/17 have rating of 83 front (1074 lbs) and 94 rear (1477 lbs). So the Federal 265/35/18 you refer to has a lower load at 93 than the OEM rating. In comparison if you check 235/40/17 tires, they are pretty much all 90 (ie 1323 like the RA1). The slicks are lower rated but then again you are not commuting on them and they often tend to be on lighter cars; while yours may indeed be lighter than 3200 lbs, many of us are still in the 3100+ range. For street driving i would not even worry about such details, but for track, well I know you like safety ..... LOL!
As they say YMMV - but the federal may be an option indeed, especially with 235/40/17 (90W) and 265/35/18 (93W). And the 235 will solve most understeer issues too!!
Last edited:
Did I miss your emails? [email protected]. I still instruct/setup work for people. Try emailing or texting me. PMs are not the best way to reach me.
Billy
Billy
Believe me if I can get billy for a day/weekend, I would. I can't even get a hold of him though, not through PM or email.
On another note, are you guys aware the federal RSR 595 R compound tire comes in 215/40/17 and 255/35/18 which are the exact sizes I am running now anyway? It says this is a street legal DOT approced competition tire. Has anyone tried them? maybe they are a worse brand but they are cheap and they are the right size!!
Adrian, here, the King of Cheap Tires!
Yeah, I've been posting about these tires a ton of times. I guess once I reply and sees I recommend something cheap he automatically dismisses it since it's cheap.
Posted a lot about the tire here:
http://www.nsxprime.com/forum/showthread.php/167526-17-18-tire-choices?highlight=federal
http://www.nsxprime.com/forum/showt...ize-(street-tire-for-track)?highlight=federal
Here's one thread when I mention the 595RS-R along with the ss595 (which is more for daily driving)
http://www.nsxprime.com/forum/showthread.php/169286-18-19-need-tire-choices-HELP!?highlight=federal
Mentioned it here in post #49, with Turbo actually quoting me on the next page (so I know he's seen it)!!
http://www.nsxprime.com/forum/showt...re-for-17x8-and-18x10/page2?highlight=federal
Summary of my feelings on it:
I have the Star Specs on my NSX and love them as a street/occassional track tire.
I have a set of Federal 595 RS-Rs on my Mazdaspeed3 as my track set and am absolutely amazed at the grip they provide and would consider them too on the NSX. Based on multiple reviews on this tire it should be great for the street too, because it doesn't need to "warm-up" unlike the Star Spec to get reach excellent grip levels.
Previous to the 595 RS-Rs were Nitto NT01s which provided excellent grip and consistent feel and track times throughout a session. They wear much faster than the federals (I got 4-5 track days on them). The Federals do tend to overheat quicker (toward the end of the session) and wear out slightly slower (after ~6 sessions), so the best hot laps will be probably laps #3-5 and afterwards they start to slick up. But for the same price of a NT01 you can have two sets of tires and would get about 2.5 times the track time for the same price. I would highly recommend them if you aren't doing any competitions and only HPDEs.
Last edited:
So you haven't tried the 215 on the NSX. That was my whole motivation. But that review on SK2I pretty much says they heat up and lose grip rapidly on the track which was my experience at the drift event with Nankangs I bought especially for the event. Once they get hot.... not much grip. That is a dangerous thing because as you lap more and more you get a bit more tired and your reflexes slightly slow, and now you also have a tire that is starting to lose grip.
People have different thresholds for this.
Yes, it's not as consistent as NT01s but there's a value vs. reward here with the Federals. Would you want to spend 100% more cost for maybe 35% more performance? Some here have different answers to that question.
Dave, there's no way you can compare an All-Season Nanking tire to an extreme performance/R comp. Any all-season tire will do that. All seasons will chunk up and starts to disintegrate. Shoot, my Hankook V12s did that the first track day I did on them. Those tires just aren't designed to take the heat. There is just absolutely no way to compare the two tires.
The experience I have was with a set of 215/45/17s mounted on OEM Miata wheels on my 2008 Mazdaspeed 3. Suspension had upgraded struts, but all alignment and springs & sways were stock. It's the same setup I used with the NT01s, except those were 225/40/18s on the OEM Mazdaspeed3 wheels.
Also keep in mind I'm 3-5 seconds FASTER in my Mazdaspeed3 than in my NSX on most tracks.
Yes, the RS-R loses grip, but it does in a predictable manner like most extreme performance/R-Compound tires. It doesn't fall off a cliff or anything. It falls off quicker than other tires in it's performance category, but nothing any driver shouldn't be able to manage.. So you'll lose a second the first lap, 2 seconds the next.. and so on.. after it heats past it's sweet spot. On the Mazdaspeed you notice it starting to push/understeer more.
But the way you describe it, it sounds like you're afraid of going straight into the wall after one turn when the grip starts going down. I just don't see that happening.
If you're doing 20 minute HPDE sessions, then it is fine because you start noticing it 15 minutes in. I think just about any driver should be able to recognize the condition and adapt their driving to suit it. Not that hard.. For a HPDE take a cool down lap and get back on it the next time around. By that time, my brakes aren't holding up either (OEM brakes with Carbotech XP10s), so a cool down lap helps out. But like i said earlier, I wouldn't use the RS-R for track competitions (I might use it for autocross though).
In any case, if you're that concerned get the NT01. Peak grip is similar, but the NT01 will cost you twice as much, hold more consistent lap times in longer sessions and have about 75% of the treadlife.
So Adrian is this going to give me a lot more grip than my AD08's is the question.
And why do you say you wouldn't use it for competition and just autox? I am assuming you are saying in a 20 minute DE session its fine but "competition" as in actual racing it's bad?
I wasn't comparing the nankang to this. I was just saying that thing was another Chinese tire that gave up when it got hot. LOL I forgot it was all season. Yeah... no wonder
And why do you say you wouldn't use it for competition and just autox? I am assuming you are saying in a 20 minute DE session its fine but "competition" as in actual racing it's bad?
I wasn't comparing the nankang to this. I was just saying that thing was another Chinese tire that gave up when it got hot. LOL I forgot it was all season. Yeah... no wonder
As for more grip than the AD08s, I don't know. I can tell you that the grip was similar between the NT01s and the 595RS-R when both were warmed up. The NT01s were more consistent though, as they were better at taking the heat. This is why I don't think I would use the 595RS-Rs for competition as the consistency goes down after 15 minutes or so.. It's great for HPDE, but if you're counting on consistent track times and keeping up with the fastest guys, this tire isn't the one.
For Time Attack or AutoX when there are definite cool-off periods or shorter sprint type competitions, I think the 595RS-R will work fine. It's the endurance type races that I would question for the 595RS-R as the best tire for the job. That make sense?
Does that make sense?
Yes, thank you. Well I am certain the NT01 has more grip than an AD08 to star spec ZII or RE11. Those are still considered extreme street tires, and their UTQG is 200+ not 140. So if they grip as well as an NT01 for 15-20 minutes, and they fit better because there is an actual 215 front perhaps I should give them a shot. I have to drive 6 hours to WGI for my next event. And then back on them. You think that'll be alright?
Dave's I don't wish to sound as belaboring with a broken record, but I still recommend that you go with 235/40/17 on the front with whatever tire selection you choose unless you are limiting your rears to 255 (which IMHO is not enough) - especially since you do have a SC and your NSX is lighter; and if I recall WGI is a high speed track. You need all the grip that you can get and also minimize understeer.
Last edited:
Hrant I have stoptechs so my wheels are offset at 37. How can I ever make 235 fit. I'm already close to rubbing with 215's.
And you know... after days of reading and research, I think I have learned more about tire tech than many guys here but the whole "wider more grip" thing still seems a mystery to me. Being you get the same contact patch area based on weight and pressure.... I read one link Ken sax gave me that said the reason for wider is actually a heat thing and not a grip thing. That the extra width changes the contact shape so a smaller percentage of the sidewall rubber is on the bottom of the wheel being compressed and released.... which builds less heat... which allows the manufacturer to go with a gummier compound. I couldn't quite decipher if they were saying the compound is actually different on the same brand and model on a wider width or not, but surprisingly I think they were saying it is the case. I am pretty sure NO ONE here understand this whole thing really well, but I think wider width may not necessarily be increasing grip. I don't know. I feel I still need more info on this.
But anyway... back to the subject... 235/275 definitely heavier, I can get 215/255 in the federals. Is that "enough"? I am inclined to just listen to your experience and not get into the science of it but how do I fit them....
also remember Jim said he went to a 205 from a 235 and almost had the same lap times! I don't know what he used in the rear with a 205.
IIRC the Federal 595RS-R has a UTQG of 140.
The Nitto NT01 has a UTQG of 100.
Not sure what that's going to tell you since you can't really compare UTQGs of different manufacturers to other manufacturers, but there it is.
I don't think driving to a from will be much of an issue if its dry the whole time (and not near freezing temps). I drove there and back on mine to Buttonwillow which is 2.5 hrs from me with no issues but it was perfectly dry and in the 80degree range. It might become an issue though when you get down on the tread close to the cords, as it would with any tire.
Last edited:
Dave - I am no tire expert, but as others noted, you need more front camber (at least get to 2.5) if you are going to track and that will help with the 235. It helped in my scenario (and I have Stoptech's too) with 235/40/17 RA1 with minor adjustment of height re outer fender rub, and pretty much eliminated it with 225/40/17 Hoosiers - after stiffening the suspension's rebound. Unfortunately the tire specs are not perfectly universal metrics in that there are still variances in how they will fit the wheel/rubbing etc. As for extra 4 lbs of weight due to size, I would venture the additional grip will more than compensate for it.
Regarding the science vs real world - I'll stick with the latter based on what "is" happening on the track vs what should be happening on the track based on theory :tongue: I have heard the tire patch spiel and frankly it hasn't registered with me. If less of the sidewall is being part of the patch then that means more of the actual flat surface is the patch right? And the actual surface was designed for better grip/traction than the sidewall which is to address/balance roll resistance and lean right? ....... so what is the issue
:wink:
Note that neither John nor Jim have a FI/SC/turbo etc.; suspension plays a role, as well as what John noted wrt ambient temps, whether the tires were heat cycled or first time out ........ you can't control all the variables to be at their optimal all the time especially if you are not tweaking for every condition. It's a compromise and you have to balance/prioritize what compromise is more/less important than others.
But then again, I putz around the track and don't care much about that 1/10th :tongue:
Regarding the science vs real world - I'll stick with the latter based on what "is" happening on the track vs what should be happening on the track based on theory :tongue: I have heard the tire patch spiel and frankly it hasn't registered with me. If less of the sidewall is being part of the patch then that means more of the actual flat surface is the patch right? And the actual surface was designed for better grip/traction than the sidewall which is to address/balance roll resistance and lean right? ....... so what is the issue
:wink:Note that neither John nor Jim have a FI/SC/turbo etc.; suspension plays a role, as well as what John noted wrt ambient temps, whether the tires were heat cycled or first time out ........ you can't control all the variables to be at their optimal all the time especially if you are not tweaking for every condition. It's a compromise and you have to balance/prioritize what compromise is more/less important than others.
But then again, I putz around the track and don't care much about that 1/10th :tongue:
What's next is registering for expo.
On another note, are you guys aware the federal RSR 595 R compound tire comes in 215/40/17 and 255/35/18 which are the exact sizes I am running now anyway? It says this is a street legal DOT approced competition tire. Has anyone tried them? maybe they are a worse brand but they are cheap and they are the right size!!
I give up. I tried to help. I think you will continue struggling with your setup with your current thought process. I don't mean to sound brash, I'm just trying to advise you that you are making compromises that are counterproductive to what you are trying to accomplish.
Last edited:
