Tires/Sizes Dunlop SP Sport vs. Yokohama AVS Intermediate

[1.2gees]

Anybody know how the AVS intermediates compare to the Dunlop SP Sport 8000?

I'm currently running 225/50/15s in the front, and 215/60/15s in the back...(Yokohama AVS intermediates)

I've been interested in wider tires, but couldn't find anything but all out race tires at a wider size. I recently found out (long live tirerack) that I can get the DUNLOP SP sport 8000 (ultra high performance) tires at 245/50/15! Through some research I've also found out these tires compare really good, with the Dunlops more grip ultimately, and a tad longer wearing (both insignificantly I'm told), however a tad less warning before breaking loose, since sidewall of the dunlops are a tad harder, oh, I presume this also means better feedback through the wheel.

Now overall that already makes the dunlop seem a tad better, but the fact that they'll be some 20 mm wider is another +.

The dunlops individual thread patterns, designed for better water evaquation (for resisting hydroplaning), also give another advantage. The individual thread(s) are longer than they are wide, which lessens the tires wanting to follow the grooves in the pavement. All good so far.

Another important question, how about fit? I'm putting the 245/50s on the stock wheels, cookies, which came with 215s originally. I don't think they'll rub since I've ran 255s in the back before, but they were on a different rim...

Tire pressures?

Overall height of the sidewall of a 245/50 tire is 122.5mm, compared to stock 215/60 of 129.6, not terribly bad, and that compares favorably to the 225/50s, 112.5. So I suppose this'll give better gearing, and closer to stock readout on the speedo as well.

Ideas thoughts? I don't think I've heard of anybody running this size on their car, is that because the ONLY ultra high performance tire in this size just became available? (Oh I hope so!)
Ahmet

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It's all the driver...

[Pilot_951S]

You may run into a problem with wheel widths. Generally the widest tire that is approved for a 7" wide rim is a 225.

If you go to wide for the rim the tire does not perform properly because the sidewalls are angled in toward the center of the tire and not straight up and down as normal. Anyway you then have a sidewall deflection problem and erratic cornering performance.

[1.2gees]

Cookies are 7.5 inches wide aren't they?

When I used to work at good year, I saw some people run way too wide tires on their *Mustangs* with no problems, but then again I suppose they wouldn't notice if the car didn't turn in a parking lot...
Ahmet

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It's all the driver...

[1.2gees]

Hey, problem solved!

Ok, I just confirmed with Dunlop, and TireRack that these tires would fit (and actually made for) 7, and 7.5 inch wide tires, and fit right!

The reason I wanted these tires is because the car oversteered quite badly at the last auto-x, and the only allowed mods I can do to avoid this are tires, and rear ride height, both of which I'm going to try!

Thanks for the feedback,
Ahmet

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It's all the driver...

[todd951]

Concerning really wide tires on not-so-wide rims, one of the local SCCA guys runs rediculously wide tires on stock rims on his Honda Civic, and he kicks everybody's ass in his class (either CSP or DSP), although he has to jack the tire pressure way up to keep the sidewall from rolling under.

If you really want to be competitive, you should pick up a spare set of cookie cutters and get some BFG R1's or Kumho V700's in whatever size will fit the cookies.
And your 944 does go into CSP, not ASP. Only the Turbo and 16v 944's go into ASP.

[Pilot_951S]

Oversteer is a beautiful thing at an autocross. Generally the problem is gteting the car to turn. Of course even I have to admit that too loose is slow.

[1.2gees]

Todd, a stock 8v 944 NA goes into Class C stock... And the 16v, along with the turbo, and 968 belong in higher classes, but that's when everything is stock...

However when modified, along with all the other 944s, the 944 NA is moved up to the A street prepared class. Doesn't make much sense, but that's the way it is.

You can find a copy of the latest rules, as altered slightly since 1999, at SCCA's official site@
http://www.scca.org/amateur/solo2/classes/st_prep.html

I heard that SCCA was thinking about having a "street tire" category at the national level. I don't know how true that is, but at my club (THSCC), we already have a street tire catagory, which basically makes me quite competitive against other cars in the class. Last time I went, I didn't really see anybody on large tires, so I might be the first one to take advantage of them, since they just became available in this size, and I doubt many know about them yet.

I've also tried to find some cookies, but couldn't, at least at a reasonable price.
Ahmet



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It's all the driver...

[todd951]

Ah, I didn't know they moved the 8v 944na into ASP this year. I was looking at the 1999 rules.

[1.2gees]

Pilot:

Are you kidding! I like oversteer 10x better than understeer, that's for sure, at least on the track. However, this car oversteered so badly, I was basically doing opposite lock at the better part of the course... It really slowed me down big time, with these tires, and lowering the rear, I think about 1.5-2.0 secs isn't too much to hope for.

My buddy who I let drive my car spun it twice, and he is no novice either, I suspect the reason for this bad oversteer was also the front springs though... I think I will take those off, and compete in C stock, a street prepared has too stiff a competition! I might mess around a bit in that class, don't know yet!

Todd,
Sucks for me to race in the fastest street prepared class, the last race winner, a 73 911 RS lightweight, european edition... 2200lbs weight, over 220hp, much better handling... How am I supposed to compete with him his time was 4 secs better than ANYBODY else, in any class! Hopefully he'll move into PRO category! (he was the winner for the last two years in canada, with a honda civic previous year, and his RS this past year!) Some talent though, and sweet car. I do believe the 944 NA is quite a capable car, but too stiff a competition, and I don't have enough $$$ to push my mods to the allowed max.

Ok, anyway, now I have something else loose in the front end, might need another alignment (I suspect strut mount coming loose, or a tie rod end, AGAIN!). I also need another expansion tank, mine doesn't look too happy at the moment! Another thing, it wouldn't hurt to get a new/updated oil pressure relief valve by than too, I don't want that thing breaking again!
Ahmet

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It's all the driver...

[Pilot_951S]

Don't complain too much about being in ASP My 951S gets bumped to E Mod. The car is stock except ofr a ported polished head, some mild boost modifications , and a hollowed out cat. It is heavy.

[1.2gees]

You're in E-Mod!?!?!

Well, I suppose you'd run midpack there, considering most people with a tad of internal engine would be in that class...

So do you auto-x your car often?

I've been competing at two, at the first one, I got a time 5 secs quicker than other people in C-Street Prepared, and my car was classified in there ONLY because of springs, and bushings...

Well, I switched back to stock springs, bushings, and put the factory optional sway bars back on the car, to my second auto-x, and got a trophy there...

I love the car, and we kinda work together real nice, I enjoy driving the thing at it's limit of traction at an auto-x, too bad the transaxle is broken again! I'm looking to buy a Nissan Sentra SE-R (very good auto-xer, will spank a stock 944 8v NA, and easy to explain to the parents), while I keep, or sell the 944. However, I plan to return to the Porsche marque when this school year is over, with a 951, or a 968, IF I sell the car, if not, it will be sold then, to get one of the replacements mentioned...
Ahmet

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It's all the driver...

[porscheboi928s/c944t/n]

ha you taught about sumitomos??same as the dunlops sp...actually sumitomo is the mother company of dunlops(just want o let you know)..also kumho tires are good but i really haven't check the tire wear....ohhh also check www.carparts.com for the tires..cheaper than tirerack...

[porscheboi928s/c944t/n]

sumitomos same as dunlops..sumitomo mother company of dunlops....kumho tires good tires...also check sell tires cheaper than tirerack.....i now am using the nankang ns-1 tire(what a brandname)it is the same as falken with less treadwear...

[1.2gees]

I WOULD consider them, but I already bought the rear two, and would LIKE to keep all tires same brand, if they're same size...

BUT also, from NON-race tires, no other tire is made in 245 size, that are approved for 7 inch wide rims.

If I buy another car (planning on it), than I'll buy a good set of race tires, (along with another set of rims)and there are plenty available at the size, approved for the 944 rims.

Many people recommended against 245s, saying too much drag, but in my experiance, they literally transformed the car, I won a trophy with THSCC, using 245/50/15s in the back, and 225/50/15s in the front.
Ahmet

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It's all the driver...

[Pilot_951S]

Oddly I usually win the class in E Mod because there aren't to many people who are runnning at the limit of the class, they are people like me who don't fit into the other classes, most of them can't drive and I whoop them.

However I often get beaten by Cars that run in Prepared because they are done to the rules limits and the drivers are good.

In PCA events I usually go for FTD and I'm usually about .5 secs from FTD.

[matt951]

[QUOTE]Originally posted by 1.2gees:
[B]Anybody know how the AVS intermediates compare to the Dunlop SP Sport 8000?

Yes I changed from the Dunlop to a weather tire which has largest contact patch known for a wet. I drive more confidently in wet today. With Dunlop 8000, I would occasionally but unintentionally do a 360 spin driving out of the car wash. My 951 is modified euro....255/40-17 Yoko AVS Sport & 225/45-17 on 968 cup wheels. Euro has German stick on blinkers and brakefluid warnings and etc.
http://www.yokohamatire.com/04b2a.html

[1.2gees]

I appriciate feedback on this, however my main focus is in the dry...

The SP 8000's contact patch looks to be a little narrow(-er), in comparison to the AVS. However running the larger size (225/50/15 vs. 245/50/15) gives larger contact patch. Not to mention better grip overall. However the 225s cost less, have lower sidewall height, and so forth.

I have gotten 245s for the back, and 225s for the front, I plan to get 245s all around, when the 225s wear out. However the 245s make the car MUCH harder to throttle oversteer, specially the kind when you need it instantly, even if at low speeds, and not cornering too hard, such as in an auto-x, around a VERY tight turn.
Ahmet

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It's all the driver...

[rmdesjardins]

How did the Dunlop Sport 8000's end up for you. I am looking at purchasing the 245x50x15 rear and 225x50x15 front for my 84/na. You have any pictures after install?

[Blackfoot]

talk about old topic resurrection...almost two years since the last post! do they even still make intermediates anymore?

for some more money, you can get avs sports. i know they cost like 50% more, but they do last longer than most maxgrip tires.

[rmdesjardins]

Didn't mean to resurect the past was just interested in the Dunlop Sport 8000's and have heard of people using them in the above config. The 245/50-15 rear and 225/50-15 front. Just looking for pics. I guess I should have created a new post

Ray