tire for fun-to-drive, not ultimate grip: RT-615 vs. g-Force Sport

[95lstegman]

i'm having a hard time finding tires that come in the size that i really want to run in the rear, but these two both do and neither is all that expensive.

street-driven car + road racing, no auto-X or other low-speed venues, no headlights (covers attached to small brackets), no wipers, lots of stuff removed/stripped wiring harness, current weight:whp ratio=7.9:1 (6.42:1 @ flywheel), so traction is a relative term.

i care more about the pleasure and ease of driving. i want a stiff sidewall, which i already know the RT-615 has in spades, and easy transitions into/out of traction. i've ridden in cars with both tires, but it's hard to sample second-hand. i'd rather read descriptive thoughts from those who have driven on them and thought about their experiences a bit.

the price difference is noticeable, but not that important. i'm worried because if i run the RT-615, i'll have a front tire exactly 1" shorter than the rear, which means running a 1" ride height difference to keep my ~55% rear weight bias. anybody actually think the extra 1" fender gap isn't worth the performance of the Falkens? i have 1" of front roll center adjustment, already maxed out in that direction anyways, but suspension geometry is only mildly important to me. suspension reaches steady-state very quickly, so transitional loading of the inside isn't a concern.

any focused comments on these tires would be very appreciated.

[crackler]

What size rim & tires are we talking about?I have the 615's on my Miata, which is mainly used for AutoX. They have lots of grip, but they tend to not warn much before they give up the ghost. My peice of crap all seasons scream for mercy before they loose all traction, the 615's just kind of slide, then break loose. They take a good amount of slip angle, which is probably part of why they break away so fast. They go from singing to spinning quick. But I love em, you just have to be aware with them. Do the Bridstone RE10R come in what ever size you need? They arte supposed to be better than the 615's. Also Toyo and Kuhmo are coming out with new ST tires as well. If you are on 17's The Yok Neova's are the IT tire, at least for SCCA STX/STU.

[Slappy]

They have lots of grip, but they tend to not warn much before they give up the ghost. My peice of crap all seasons scream for mercy before they loose all traction, the 615's just kind of slide, then break loose. They take a good amount of slip angle, which is probably part of why they break away so fast.

I guess for Auto X thats ok but if i were on a proper race track at full tilt (not drifting) i would want some type of warning like tires screaching to let me know im about to loose traction , instead of just "grip , grip , grip then round you go".

Ive only ran these types/brands of tire so far , that i can remember on stock wheels , mild modded KA , and either Tokico HP's or my current Tanabe Sustec S-OC Type II's with factory 240 coupe weight.

Falken Ziex 512 - 205/55/15 (2 sets)

Even though the Ziex 512 is an All Season Performance tire , i found these tires to have very decent dry traction and very very good wet traction. Break away is more predictable in the dry than in the wet. They also had a funny "break in" period. Sidewall - Soft

Dunlop Direzza DZ101 - 205/55/15 (1 set) - 205/50/15 (4 sets)

A very very good all around tire for the price. I was getting these for $47 per tire at Edgeracing.com. Break away was more predictable in the wet then the Falkens but about the same in the dry. Sidewall - Firm (205/50)

Hankook Ventus HR II - 205/50/15 (1 set)

The tire im currently running. Not the best as far as a grip tire but are loads of fun for drifting and were a steal on price. Sidewall - Firm

Bridgestone Potenza ??? 205/55/15 (1 set)

Not really much to say about these tires except they had exceptional grip in the wet. If only i could remember the model. Sidewall - Soft

Yokohama AVS ES100 195/45/15 (bad decision - 1 set)

With the size i purchased , they were complete crap. There was no feedback from these tires when i was behind the wheel at all. Horrible dry & wet wheather traction. Sidewall - Medium Firm

Im yet to experience tires like the Falken RT's or the Hankook Z2's ect. My next set of tires im going to test is the Yokohama S. Drive 205/50/16 on my 16x7 30 et Advans.
Modified by Slappy at 7:33 PM 1/24/2008

[crackler]

It has been a while since I drove them, the last few events I ran R Comps. I think they give more warning than my post reads. It could be a loose nut behind the wheel as well. I have a hard time remembering for sure. I am sure they gave some warning, but I don't think it was a whole lot. IIRC they made some noise, but not a lot. IIRC they started sliding some before they broke away and had some squeal. But nothing like a "regular" street tire has. Damn my bad memory, I can't remember ****. Ask me again at the end of March. I never push the 615's on the street, they have soooo much grip that the speeds you can carry don't allow for any mistakes or surprises. If you lost it on the 615's and you were pushing the tires to the max, there would be no room / time to save it on a regular road.

If you think the 512's have good grip (I had some as well) you have to try a 615/Neova/Reo1r. Every one I now that ran the Hankocks (Z7's???) max street tire, I forget the model, hated them. And the guys running the Neova's said they where just a tick off of a full on R comp.
Modified by cracker at 8:33 PM 1/25/2008

[nismofly]

the grippier the tire, the less warning it gives before you lose it...thats why when running track days you gradually increase the grip of the tires as your experience builds

as for the OP, sorry ive got no experience with either tire so i wont toss opinions as facts, but id like to know this is on your 240 youve got 55% rear weight balance?

[Slappy]

If you think the 512's have good grip (I had some as well) you have to try a 615/Neova/Reo1r. And the guys running the Neova's said they where just a tick off of a full on R comp.

I hear what your saying , but for some odd reason i like to run "under dog" tires. Im not much a fan of tires like to RT's , Z2's or R compounds ect. This may sound crazy , but i believe that your tires should match your suspension , so one doesnt out perform the other. I believe my suspension setup is'nt a good match for tires like those. This is why i cant wait to get the Yokohma S. Drive , i think it will be a near perfect match between my suspension setup , and the only part of my car that actually touches the ground , the tires.
Modified by Slappy at 4:27 AM 1/25/2008

[nismofly]

actually thats not crazy, its what really makes a well balanced car, engine, suspension, tires, aero, etc should all be about the same level...unless youre in the process of slowly putting everything together of course

however this is one of the things that makes scca showroom stock an interesting class, because theyre running r and a compound tires, a roll cage, and a few other minor mods on an otherwise stock car

[Slappy]

its what really makes a well balanced car

Ageed

however this is one of the things that makes scca showroom stock an interesting class, because theyre running r and a compound tires, a roll cage, and a few other minor mods on an otherwise stock car

I see. I enjoy watching the SCCA Runoffs on SPEED this time of year.

[crackler]

I am with you on the driving on crap tires thing. I drove on all seasons for the first four or five years I autoXed, just to force me to be a smother driver. I don't know how much it helped, but I do know one thing. R-Comps are like Crack, once you get a taste you want MORE. But I am sticking to Street tires, 140 tread ware, but street tires none the less.

[Slappy]

R-Comps are like Crack, once you get a taste you want MORE.

lol , I might check those tires out one day. A few of my buddies rave about them.

[crackler]

To awnser the original question; RT-615's are better than the G-force's. Can you get the RE-0lr's (they are better than the 615's)? We would be able to give a better answer on other possible choices as well if we new what size tire / wheels you are looking at.

As far as the suspension geometry stuff. . . . I have no idea.

[naed240sx]

I guess for Auto X thats ok but if i were on a proper race track at full tilt (not drifting) i would want some type of warning like tires screaching to let me know im about to loose traction , instead of just "grip , grip , grip then round you go".

A good driver should not require noises from the tires to know that he is reaching the limits of adhesion. You can get all the feedback you need through your seat, steering wheel and pedals. 615's are super predictable...you can run them right to the ragged edge of grip with ease, and the transition to slip is gradual.

[naed240sx]

but suspension geometry is only mildly important to me. suspension reaches steady-state very quickly, so transitional loading of the inside isn't a concern.

Suspension geometry is only mildly important to you because cars on stiff springs reach steady-state quickly? This is a horrible belief for anybody interested in improving the handling of their car. I bet you are one of those guys who lowers his car and then neglects to get an alignment because "it's close enough"