We are continuing to truck along with the Acura Integra Street / Track project and are onto our next step in the process. As you have previously seen we took a bone stock Acura Integra to the track in the first episode and then progressed to some mild suspension tuning and a limited slip differential installation. As the project rolls on we have been figuring out the next thing to tackle as we enjoy the car on the track.
After the first 3 test days at The Firm in Starke, FL we are still seeing a lot of outer tire wear and we have deemed this caused by excessive body roll and/or not enough negative camber. The logical choice is to put some track specific dampers with higher spring rates in place to flatten the chassis during cornering and at the same time we added some more front camber. Being able to plant the front tire better during cornering would hopefully help better our lap times. This is a setup that is going to be more track specific to The Firm than possibly other tracks but to give us the best shot at good, repeatable and reliable data we are tackling the issues at hand.
The Integra project is currently scheduled to be a double duty car in that we hope to enjoy it on the street as well as the track so picking pieces that will serve that theory best is always in the back of our mind. Based on past experience with higher end coilovers we had KW Variant 3’s in mind as to what we wanted to run on the car for their excellent double duty aspects but due to a manufacturer backorder we chose to ask our circle of friends if they had anything to offer. A local racing friend had recently picked up an Integra Type R with some very nice coilovers on it and as his plans didn’t include using them they were offered to us for the project. What we purchased are a set of Koni 3011 series double adjustable dampers with coilover sleeves and custom rate Eibach springs as well as Karcepts Spherical Top Hats. This is the same type of coilover that you will find on some of the most popular SCCA, NASA and Time Attack vehicles running at the top of their classes. With a huge adjustment range and the possibility to swap spring rates as needed this can technically be the last set of dampers you will ever purchase. The suspension was purchased with 700lb front springs and 600lb rear springs installed so we just stuck with those for initial testing. A pair of brand new OEM Honda Integra Type R Rear Lower control arms were purchased for installation. At the same time as installing the suspension we changed the front camber kit from the Revo Technica parts that were on the car to the SPC Ball Joints utilizing the OEM Front Upper Control arms as they are more capable of giving us a wide range of camber settings to dial in.
We ended up with -3 degrees of negative camber in the front with 1/16” toe out and -2 degrees of negative camber in the rear with 1/16” toe out. Getting use to how much stiffer the chassis was at the track was the first order of business. The car wanted to be driven differently to achieve the optimal lap times. With the softer Koni Orange and Eibach Pro Kit suspension you could almost manhandle the car, just throw it into the corner, let it slide around a bit and mat the throttle to pull you out. With the Koni 3011 setup it took a smoother style. Hard on the brakes and smooth entry allowed the car to settle better and get on the throttle as early possible to pull you out. After about 25 minutes on the track we were able to get back to our previous best lap times of mid 1:26 minutes running a 3 lap stretch of 1:26.4, 1:26.3 and 1:26.5. With the consistency in place and the lap times just undercutting the times from the last trip to the track it was time to start dialing in the new suspension.
The first change was disconnecting the front sway bar. The car was exhibiting a push characteristic so in order to free up the rear end of the car and knowing we had some stiff springs up front to help with the body roll the front sway bar was unbolted. The car immediately was looser to drive on initial entry and after some laps to get used to the change we were able to run another 1:26.4 lap time. So the result from the driver seat was the car was capable of similar lap times but took more effort to get there. After lunch we started making damper changes. First we added rebound in the front only to help neutralize the handling and it worked but not enough to gain any lap time. Giving the shocks even more rebound adjustment front and rear made the car easier to drive but again no gain in lap time. At this point in the day the thought was had that it was incredible how much we could make the handling characteristics change with damper adjustments and sway bar options but so far not much gain in lap time. The amount of effort to achieve similar lap times was all over the board depending on what damper and sway bar settings were used.
Ultimately we didn’t make any huge lap time gains over the mild street suspension we had on the car but depending on the setup we used it was less effort to achieve the same laps and the consistency was increased with the new parts on the car. The front left tire still had more outer edge wear than we wanted to see but looked much better across the entire tire and some quick tests with a tire pyrometer showed a good average from inside, middle and outside readings. From a racers perspective running 20 laps of 1:26.3-1:26.5 versus 10 at 1:26.4, 5 at 1:27.0, 3 at 1:27.3 and 1 at 1:26.8 makes the new suspension a clear cut winner in the battle to the front. But if every last tenth of a second on a track doesn’t matter to you and you enjoy a more comfortable ride on the street quality mild suspension components like the Koni Orange shocks and Eibach Pro Kit springs work wonders.
Current Lap Time Results (at The FIRM in Starke, FL):
Stock 2001 Acura Integra LS, Dunlop Direzza DZ102 Tires – 1:36.3
Stock 2001 Acura Integra LS, Bridgestone RE71r Tires – 1:30.2
2001 Acura Integra LS, Suspension Mods – 1:27.5 - (Eibach Pro-Kit Plus, Koni Orange Shocks, Camber Kits, Aligned, RE71r Tires)
2001 Acura Integra LS, Suspension Mods, MFactory Helical LSD – 1:26.4
2001 Acura Integra LS, high end dampers, MFactory LSD - 1:26.3 - (Koni 3011 Series Dampers, Eibach 700lb Front / 600lb Rear Springs, Eibach 25mm Front, 17mm Rear Sway Bar)