Civic Si in GS

SandyEggoSi

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A 4 year old tire will lose some of its adhesion capability as rubber hardens over time. How much depends on how it is stored. In a temp/climate controlled warehouse in the shade is good. If tires are stored in bags, even better. Sitting in the sun in the side-yard in someones backyard in the desert...not so good.

Ideally, u want the freshest rubber possible to be most competitive. Adding 4 years to the shelf life of an RE71R for example may add .5 to 1 sec a lap over a fresh set. These are things that someone should test...someone being TireRack. Lol. Because if they can prove with lap times that an older tire loses grip (something we already know) we would be inclined to buy fresh rubber more often. =)

BUUTTTT, looks like at least one of U has an event TOMORROW so LET US KNOW what tire pressures you settle on since you're running a rear sway bar. I know auto-x pressures tend to be lower than street pressures typically, but it will give me an idea of what is optimum for the street. RIght now I'm at 41/37 psi but thinking of going 42/36 for a little added anti-oversteer insurance. Lolz. On the street, I have yet to get the car to give up at either end other than a quick skip here or there over a mid corner bump. Really anxious to hear from you guys where the car is at the limit.

I'm on 18x9 +40 with 245/40/18 all around but almost want to throw some 265/35/18 in the back. Yeah, I know that would make the diameter in the back marginally smaller at 25.3" vs 25.6" front, but I'd like a little more grip back there as oversteer insurance with the Type R rear sway on there. Would give me the confidence to corner even harder without fear. But yeah, as of now that set with the RE71R is stacked up in my living room with a 24" piece of glass on top being used as a table and I'm running some 245/40/18 Pirelli PZ4 for the street. Grip is amazing even with those (Tire Rack has them on par with Extreme Contact Sport in the dry). Speaking of which, I have some Conti ECS in 225 on 17x8 my other car after running RE71R in 245 on that same car on 17x9 and the difference in grip was astounding! So, I'm expecting a huge increase in grip when I get the RE71R mounted up on my Si.

One last thing, let me know if you guys have the same suspicion as me that the car is over-damped in "Sport" mode. I mean, for smooth pavement it might me fine but when pushing it on broken pavement, I suspect I may have more grip in standard susp setting.
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sibanez

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Dude, you over overthinking the oversteer thing with the Type R RSB. This isn't a BRZ/FRS, these cars are very stable.

I'm running it on my SI and have had no issues, it is very predictable, even on snow tires and in the snow.

The car can get light in the rear if you lift in a turn, but that's true for any front-engine car.

If you want the car to be neutral, try running the same pressure all around.

There's really no need to run that much pressure up front, especially on the street. You run those numbers to avoid the sidewalls from rolling over and to protect the outside edge from camber wear. I'm running 35psi all around on the Extreme Contact Sports and it drives well, no issues, even in the cold and rain.

The rear is tricky. I know a few guys who actually run lower pressures in the back to induce oversteer. The theory is that the sidewalls being softer allow the car to use them as a spring almost, while others, like myself, run extra pressure in the back to get the car to turn-in faster. I'm not a talented enough driver to know either way.

As for the 265/35/18 in the back . . . . you can stuff them in the front, should be OK for street use, but will tear up your liner and the tire for autocross.

A 4 year old tire will lose some of its adhesion capability as rubber hardens over time. How much depends on how it is stored. In a temp/climate controlled warehouse in the shade is good. If tires are stored in bags, even better. Sitting in the sun in the side-yard in someones backyard in the desert...not so good.

Ideally, u want the freshest rubber possible to be most competitive. Adding 4 years to the shelf life of an RE71R for example may add .5 to 1 sec a lap over a fresh set. These are things that someone should test...someone being TireRack. Lol. Because if they can prove with lap times that an older tire loses grip (something we already know) we would be inclined to buy fresh rubber more often. =)

BUUTTTT, looks like at least one of U has an event TOMORROW so LET US KNOW what tire pressures you settle on since you're running a rear sway bar. I know auto-x pressures tend to be lower than street pressures typically, but it will give me an idea of what is optimum for the street. RIght now I'm at 41/37 psi but thinking of going 42/36 for a little added anti-oversteer insurance. Lolz. On the street, I have yet to get the car to give up at either end other than a quick skip here or there over a mid corner bump. Really anxious to hear from you guys where the car is at the limit.

I'm on 18x9 +40 with 245/40/18 all around but almost want to throw some 265/35/18 in the back. Yeah, I know that would make the diameter in the back marginally smaller at 25.3" vs 25.6" front, but I'd like a little more grip back there as oversteer insurance with the Type R rear sway on there. Would give me the confidence to corner even harder without fear. But yeah, as of now that set with the RE71R is stacked up in my living room with a 24" piece of glass on top being used as a table and I'm running some 245/40/18 Pirelli PZ4 for the street. Grip is amazing even with those (Tire Rack has them on par with Extreme Contact Sport in the dry). Speaking of which, I have some Conti ECS in 225 on 17x8 my other car after running RE71R in 245 on that same car on 17x9 and the difference in grip was astounding! So, I'm expecting a huge increase in grip when I get the RE71R mounted up on my Si.

One last thing, let me know if you guys have the same suspicion as me that the car is over-damped in "Sport" mode. I mean, for smooth pavement it might me fine but when pushing it on broken pavement, I suspect I may have more grip in standard susp setting.
 

Forcino

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I agree, those pressures seem really high. And also 18x9's take you out of GS. My plan in to run 33-34 in the front and 31-32 in the rear on 245/45/17.
Our Tuesday night course is a 40 sec course, so I won't be losing an entire second from older tires. We do the same course at every event on Tuesday nights, and last week I ran a 39.0 in my Elise. So, I'm curious what I'll do tomorrow in the Si.
I changed my mind, and canceled my Sirimoto RSB order. I bought a CTR RSB from a member here (still with the good price). I look forward to getting rid of that understeer. My prediction is that it is not really going to oversteer and if it does it will be minor and very controllable.
 

5inn

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Dude, you over overthinking the oversteer thing with the Type R RSB. This isn't a BRZ/FRS, these cars are very stable.

I'm running it on my SI and have had no issues, it is very predictable, even on snow tires and in the snow.

The car can get light in the rear if you lift in a turn, but that's true for any front-engine car.

If you want the car to be neutral, try running the same pressure all around.

There's really no need to run that much pressure up front, especially on the street. You run those numbers to avoid the sidewalls from rolling over and to protect the outside edge from camber wear. I'm running 35psi all around on the Extreme Contact Sports and it drives well, no issues, even in the cold and rain.
I don't think there's any need for 'oversteer insurance'. On a FWD autocross car, it's very difficult to have too much oversteer. Worst case, you can adjust pressures to suit your driving style.

I plan on starting at mid-high 30s to see where rollover is at on the fronts and adjust (down) from there. I'd rather protect the tire than eek out every bit of grip.

There is 100% no need to put a wider tire on the rear of the car. Please don't do this in person or you will get laughed at.
 

JSTCorrin

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Coming from someone who owns 3 Focus ST's.. The Si STILL doesnt rotate nearly as well as a stock Focus ST even with the Eibach 20mm rear bar were running on the stiff setting.
 


SandyEggoSi

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I don't think there's any need for 'oversteer insurance'. On a FWD autocross car, it's very difficult to have too much oversteer. Worst case, you can adjust pressures to suit your driving style.

I plan on starting at mid-high 30s to see where rollover is at on the fronts and adjust (down) from there. I'd rather protect the tire than eek out every bit of grip.

There is 100% no need to put a wider tire on the rear of the car. Please don't do this in person or you will get laughed at.
I know, I know...lol. I'm a top 5 auto-x guy and always in the hunt for FTD in Street Mod when competing in my last car. I know this is a GS thread so I understand most mods and wider wheels would take me out of GS.

Technically tho, this is the wife's car and she will be driving it to work at some point, so a little added insurance in case she had to lift throttle, slam the brakes, load the frt susp, hit a mid corner bump and swerve hard in the rain all at the same time without oversteering is what I'm thinking (worst case scenario). Lolz.

The pressures I'm running/quoted above are on my Pirelli PZ4's currently. They're really light at 21 lbs per tire (softer sidewall) vs 26 lbs for the RE71R. As such, they require more static psi in the tires to compensate. Also, I'm talking about street pressures optimized for wear/mpg/response, not just auto-x which would of course be lower. When running auto-x, I've seen it fit to drop pressure by 6 psi compared to street pressures or so to get things working properly with the added heat in the tires on a sunny day.

Regarding running wider rears, just thinking in theory and it'll most likely never happen. I'll reiterate what I've said before that I don't have enough seat time in this car at the limit. I will say that over-thinking things is a good thing and I am very particular to details on car setup which is how I've been able to set FTD in the past; cause admittedly, I had a better car than I was a driver. But I'll say this...it sure is fun to be in the "cool" club and fraternize with the fast guys and talk about all those slowpokes in stock class. =P
 

SandyEggoSi

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Coming from someone who owns 3 Focus ST's.. The Si STILL doesnt rotate nearly as well as a stock Focus ST even with the Eibach 20mm rear bar were running on the stiff setting.
I used to be a valet at a high end place and our parking garage had a nice 180 sweeper but with a little dip at the end and I was impressed with the Focus ST and how composed it was both taking that 180 going up and down the garage. ND Miata takes the cake tho for most composed car around that same turn. Focus ST was 2nd. Wish I could rate more cars, especially the higher end ones around that corner for comparison but we never took those downstairs but rather kept them up front. Cayman GT4, 911 GT3, Lambo Hurracan, Aventador, Ferrari 458 Italia, Audi TT-RS, All sorts of BMW M models...fun job and yet I hated it at the same time. Lol. Such a blue-ball experience never really getting to exploit the car's abilities. Plus, being stuck inside a garage all day every day was kinda soul crushing...even if I was literally 100 ft away from the bluff on the ocean.
 

5inn

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I know, I know...lol. I'm a top 5 auto-x guy and always in the hunt for FTD in Street Mod when competing in my last car. I know this is a GS thread so I understand most mods and wider wheels would take me out of GS.

Technically tho, this is the wife's car and she will be driving it to work at some point, so a little added insurance in case she had to lift throttle, slam the brakes, load the frt susp, hit a mid corner bump and swerve hard in the rain all at the same time without oversteering is what I'm thinking (worst case scenario). Lolz.

The pressures I'm running/quoted above are on my Pirelli PZ4's currently. They're really light at 21 lbs per tire (softer sidewall) vs 26 lbs for the RE71R. As such, they require more static psi in the tires to compensate. Also, I'm talking about street pressures optimized for wear/mpg/response, not just auto-x which would of course be lower. When running auto-x, I've seen it fit to drop pressure by 6 psi compared to street pressures or so to get things working properly with the added heat in the tires on a sunny day.

Regarding running wider rears, just thinking in theory and it'll most likely never happen. I'll reiterate what I've said before that I don't have enough seat time in this car at the limit. I will say that over-thinking things is a good thing and I am very particular to details on car setup which is how I've been able to set FTD in the past; cause admittedly, I had a better car than I was a driver. But I'll say this...it sure is fun to be in the "cool" club and fraternize with the fast guys and talk about all those slowpokes in stock class. =P
Are you at the San Diego Match Tour this weekend? I don't remember seeing any Civics signed up but maybe in your SM car?
 

SandyEggoSi

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Are you at the San Diego Match Tour this weekend? I don't remember seeing any Civics signed up but maybe in your SM car?
No. =( Last I read they were very close to getting the required number of entrants but I'm sure they got them by now. I refuse to run auto-x in San Diego because the pavement has gotten to be of such poor quality and wears out tires so fast. Shame because the old Chargers stadium parking lot is so large that courses are 1 min long or more. Prob is when each lap costs you $20-$30 in tire wear...it is hard to get excited for (3) 1 min laps and the time commitment of a good chunk of a day for tech, run group and working the course.
 

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The Si was pretty good Tues night. I got 9th in PAX out of 101, but I know I left at least a half sec out there.
I also think that some of you were right, and that these older tires may wear a bit faster than normal. The side wall was ok, but you can see in the pic, there seems to be a more wear than normal on one of the inner treads (after only 5 runs where I only pushed it on one of the runs).
I'm excited to get the CTR sway bar on there and see what it can do next week!

Honda Civic 10th gen Civic Si in GS IMG_1119.JPG
 


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Are you guys using the front strut tower bars at all especially with the upgraded rear sway bar? Is this mod really not needed. I have the ultra racing one piece front strut tower bar that I just got. Haven’t installed yet.
 

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Are you guys using the front strut tower bars at all especially with the upgraded rear sway bar? Is this mod really not needed. I have the ultra racing one piece front strut tower bar that I just got. Haven’t installed yet.
You’re only allowed 1 after market bar in GS. So it’s either the front strut OR rear sway. And rear sway has more advantages for tight courses designed by miata drivers (which is my case)
 

SandyEggoSi

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Are you guys using the front strut tower bars at all especially with the upgraded rear sway bar? Is this mod really not needed. I have the ultra racing one piece front strut tower bar that I just got. Haven’t installed yet.
I'd can the Ultra strut bar. IIRC, you can't use the OEM slotted upper strut mount with it. It will FORCE you to run the full positive camber up front that the car came set with stock. THat said, I dunno if you can remove the locating pin and utilize the OEM slotted strut mount in GS anyway, but if u do it WILL give you approx -0.3 more degrees neg camber which is nice.

The only bar I've seen so far that will work with the slotted mount is the Tanabe strut bar.
 

5inn

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You’re only allowed 1 after market bar in GS. So it’s either the front strut OR rear sway. And rear sway has more advantages for tight courses designed by miata drivers (which is my case)
I don't think the front strut bar is legal either way in Street class. If it was a front sway bar it would be a different story.

The Si was pretty good Tues night. I got 9th in PAX out of 101, but I know I left at least a half sec out there.
I also think that some of you were right, and that these older tires may wear a bit faster than normal. The side wall was ok, but you can see in the pic, there seems to be a more wear than normal on one of the inner treads (after only 5 runs where I only pushed it on one of the runs).
I'm excited to get the CTR sway bar on there and see what it can do next week!

IMG_1119.JPG
I thought the V720 was known for poor wear. I had a friend give them a shot and they didn't last anywhere near as long as RE71Rs, even though they have the 'same' 200tw rating.
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