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Discussion Starter #1
Alright guys, I know there are a few of them floating around on here already. They are part of what brought me here, but this is my H-street Civic SI log. I'm going to do my best to enclose all the information I gather while getting this car up to speed (I hope).

My background: I have been racing karts/cars since I was 9 years old. I have competed in SCCA solo XP, SSM, DSP, and various other classes with reasonable success at regional national tours etc. I own/manage the shop and a High-performance shop in Portland Oregon, so I have a few more resources than normal to get things going quickly.

The car:
2007 Honda Civic si, 4 door, (i know the wheelbase sucks)

The current parts:

Koni Sport inserts front and rear
Kosei K1 TS +50mm offset 225/45-17 Bridgestone RE71-r
Factory Honda camber bolts x4

Parts currently waiting to go on:
ARP extended front wheel studs.
12mm front wheels spacers
K&N drop in filter
Straight pipe axle back.

You will notice I have not put a sway bar on the car yet, I have some real reservations about just going with the big rear bar to start. Primarily because this car is so camber challenged. The firs couple events of the year I will be recording the operation of the rear suspension and making a choice on which sway bars to buy. It very well may end up being what everyone else has right now. Since the car has LSD however I am reluctant to make a decision about the rear bar without some testing.

I will be doing a tune-up on the car on our dyno, as well as testing the K&N and Axle back to see if there is any real gains there.

I drive this car little on the street, and don't care about tire wear so the alignment can be as aggressive as I dare go.

I was happy to see the car so well balanced out of the gate, although some more front bias would be better for autox (coupe guys). This was with just under 1/3 tank of fuel, race tires on, no spare wheel and tire, stock muffler. Only thing left to pull would be floor mats/straight pipe.

weight are as follows: total=2840 (can't post pictures yet)
lf=880
rf=887
lr=537
rr=536


The alignment is a major challenge, I was not able to achieve even 0.7* on one side. I will likely replace lower arms and top hats in hopes to decrease compliance and get some camber back. But we will see. I was able to eak out a good amount of rear toe-out, which helped entry rotation a lot in parking lot testing.

current alignment=
Camber lf=-.77 rf=-.66
toe out=1/8 total
caster lf=6.25 rf=6.55

Rear:
camber ~1.5*
toe out= 5/16 total

Also note, My car had significant binds in the rear. I had to completely loosen the inner arm mounts etc and bounce the car to free them up. There was over an inch difference at full droop!


First even is in two weeks, Ill report back then with what I have learned!

Zack
 

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Discussion Starter #2
Well I took a prybar to everything today and got the alignment much better. We also loosened all the suspension mounting points, strapped the car onto the bump stops, and re-tightened everything to get rid of binds. Car is much better!

Camber lf=-.88 rf=-.97
caster lf=7.34 rf=7.22
Toe-1/8th total toe out

Rear
camber lr=-2.11 rr=-2.45
toe -5/16 total toe out.

First outing next weekend.

Zack
 

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I will add that someone suggested I run a front bar on mine for the same reason you mentioned. Once we went to Lincoln I'm glad we had the rear bar, even with the rear toed out as much as we could get, it still wouldn't rotate like we wanted. Also I don't think the RE71R match the characteristics of the car, or how it needs to be driven to be fast.

Another thing I was considering had we stayed with HS was going to the "C" stamped arms on the rear to remove some camber to help rotation.
 

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Discussion Starter #4
First outing yesterday went very well for me. The hours on alignment rack/maintenance seem to have paid off well.

I was able to pull off top pax against some fully prepped local cars.

I had no issues rotating the car when needed with the current setup, so I will be trying to run a slightly stiffer front bar to help with the transition response. I really think the rear bar will just make the car more unpredictable in quick transfers, as I have noticed with many other FWD cars.

The word of the day was patience.....I just had to get the car shut down, stay nice and tight on everything and allow the lsd to pull the car out of the tighter turns well. I don't think I would have anywhere close to the same results if I wasn't years into switching to left braking, I relied on it heavily to catch the car in rotation and trail brake very deep. I was able to get back to throttle earlier than pretty much any car out there.

I started at 35psi f/r. As the temps came up I notice a bit too much roll on the front tires, so I increased pressure to 36 f/r. To add slightly more rotation in high speed corners I eventually went up 37 in the rear, this added good transition oversteer in the fast sections.

Next weekend we will run in the rain, and I am doing the front wheel bearings and studs this week so I can use my newly made 12mm spacers in the front.

Thanks,
Zack
 

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Discussion Starter #6
Car is currently on Koni Adjustable front and rear.

I did two events of testing on the factory sway bars before making a decision about which way to go. With cameras we found the inside rear wheel to be unloaded almost all the time during cornering. Once the inside rear wheel is off there is no more weight transfer to occur, based on this we chose a front bar for the car.

We installed a 30mm solid Eibach bar on the front of the car halfway through our last outing. We had to change shock setting some to allow the car to rebound faster in low speed corners to help with acceleration. After this was done though the car showed considerable pace.

Solostorm data showed around 3.5mph and 3 tenths of a second improvement in slalom speed (5 cone, 50 foot). The car is MUCH faster in high speed transition with almost no loss in low speed. The other nice thing is front tire wear is much better controlled also. When pushed hard the car will still pull the inside rear, verifying this was the correct sway bar choice for higher grip levels. There is a chance in the rain we will need the stock bar to get good rotation.


We have 54 runs this year already, 3 top pax finished, 2 of them agains high level national drivers. Everything is looking good. We have one more day of testing before starting our national efforts for the year.

We will be switching to BFG Rival 1.5 for Crow's Landing National tour at the end of next month.

Thanks,
Zack
 

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Discussion Starter #7
I will add that someone suggested I run a front bar on mine for the same reason you mentioned. Once we went to Lincoln I'm glad we had the rear bar, even with the rear toed out as much as we could get, it still wouldn't rotate like we wanted. Also I don't think the RE71R match the characteristics of the car, or how it needs to be driven to be fast.

Another thing I was considering had we stayed with HS was going to the "C" stamped arms on the rear to remove some camber to help rotation.
I beleive rotation would be better with a front bar, as grip goes up camber mainenance becomes even more important for the grip.

As much camber as possible in the back is my thought on the rotation, because the mass is low and the car is stiff you end up not having enough roll to use the camber. I just jack the pressure up in back to adjust rotation levels, but I don't use the ouside 3/4 in of the tire at -2.5* which greatly helps rotation. It also saves the sidewall for the front of the car.

RE71r has been great for us so far, just have to be patient. We were showing 1.25 peak g's and 1g skidpad on a medium grip surface. Not too shabby.

Zack
 

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How are the 2 door cars performing? Any competition?

There is also argument in favor of the 4dr chassis due to the added rigidity. Definitely a fine line to balance though.
 

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Discussion Starter #9
Hey guys sorry for the late update on the Hoopty-street Civic.

I had my first major outing with the car last month at the Crow's Landing national tour in California. We switched to the new Rival 1.5s prior to this event expecting it to be warm and also very high wear.

We had around 8 runs on the practice course to get the car dialed in, and with the added grip the car was very locked in as expected. By stiffening the front shocks and changing the tire pressure stagger to 36/50 we were able to get the car to rotate well and make somewhere around 1.09g sustained grip in sweepers.

The courses are very fast at Crow's (we reached 74mph), because of this there are usually some high-risk/reward elements. On day one I managed to lead the field over my co-driver with a solid margin. I also managed to maintain 16th in pax overall on day one, out of 243 drivers. I was happy with this result as it is much higher in index than I have seen out of HS car at a national level event in a while. Plus we were among fast company on a very fast course.

Day 2 the course was much more suited to higher powered cars as the course had become much more acceleration based. I was able to extend the lead up to 2.3 seconds over my co-driver and around 6 seconds to next car back.

Needless to say I'm happy with the result, I would have trophied in DS and CS with my runs, and been mid pack in STX. We will be continuing to update the car getting read for nationals this year, but it is very good as-is.

Also, on this grip level there is no way the rear sway bar is an advantage. We got the car to rotate just fine without it, and the car was still tri-poding everywhere even with the stiff front bar. We would have just been losing valuable camber during cornering and putting even more hurt on our tires.

Ill try and get some pics and stuff going on here when I get enough responses in.

Thanks,
Zack
 
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