Making progress with the Racefix Parts Racecar!

We had a very successful sponsor ride night this week in the Racefix Parts Production Touring racecar which acted as a great opportunity to test the chassis changes we’ve made in the car in the past couple of weeks while taking some friends out in the passenger seat!

With the recent resurfacing of some sections of SMSP aswell as having a human ballast in the silly seat it’s difficult to gauge just how much of an improvement the recent updates have made but one thing is for sure - it felt a wholeeee lot better. Equaling my laptimes with the last time I drove the car, this time with a passenger in the car, 34 degree ambient temps, a less than desirable surface in some spots, motor thats lost some ponies and a gearbox with more crunches than a box of Coco Pops - more on that soon.

Chassis Updates.

A couple of weeks ago I got the car up on the hoist at the PVS where we removed the heavier sway bars and reset all of the shocks. I suspect the car may have been corner weighted in it’s previous life as the heights and pre loads of each shock and spring were all over the shop. The car was essentially tied up in a knot with some crazy pre loads in the chassis.

While the car was on the hoist I noticed some issues with the front brakes where an inner pad was wearing like a door stop. To avoid any future problems I figured the best course of action was to take the CP9200 calipers in to V-Sport to be rebuilt with fresh seals and replacement piston with some heavy scoring on one of the pistons.

What better time to swap out the front rotors for a 2 piece PFC direct drive unit that i’m testing in the race car before offering to our customers at Racefix Parts and a Ferodo front and rear brake pad package with DSUNO’s upfront and DS2500’s in the rear. It’s a familiar pad package will make it an easier baseline to develop the car from. These are all things we now sell on the store along side AP Racing, Brembo and Endless brake kits!

Just like a chocolate milkshake, only crunchy?

The very first lap I turned in the new car and felt a slight resistance and crunch into 4th and 5th gear. It’s fairly common in these cars particularly in race cars where the transmission gets quite hot and operators can sometimes rush between the gears. We chucked a heavier weight oil in the box to try and work with the gearbox cooler to reduce wear in the box at higher temps as a bit of a band-aid solution. Unfortunately it looks like i’ll be ordering a brand new gearbox and chucking it in before the season starts. Thankfully Racefix Parts has access to the entire OEM parts catalogue at affordable prices!

Have the horses bolted?

The car has always felt on the slow side but coming from 265kW in #project86 going back to 120kW was always going to feel a bit ordinary. The 3 times i’ve driven the car now it’s gone slower and slower to the point now where i’m pulling 5th gear at the grandstand - about 100m later than I should be and the cars going so slow that towards the end of the night I could keep the gas pedal pinned through T1 and be fairly comfortable with it which definitely isn’t right.

I’ll have to get the car on the PVS Tuning dyno and try and see exactly what's going on and see if there’s any power to be had in the way of some intake or exhaust mods.

As you can see from the AIM data below the poor old engine is hurting. The blue line is the race car from the ride night this week. The red line is from #project86 about 18 months ago on E85 (with a 132kW tune). Going off the figures from the last time the race car was tuned the 2 cars should be making very similar power but it’s pretty clear to see they’re not. Even with pretty woeful mid corner speeds 18 months ago the road car still claws back the same speed.

The circled section of data is the exit of the hairpin (Turn 8) on the run upto the last complex (turn 9). The road car starts 10kmh slower out of the hairpin but gains a HUGE 21kmh over a 500m run - don’t forget these cars SHOULD be making the same power. Something is very wrong with the tired old donk in the race car.

All things considered i’m pretty happy with the direction the car is going in, being in the lap time window while being dramatically down on power and still not quite happy with the point in the front end is a great sign. The car is still quite understeery as it rolls and transfers so much weight over the relatively softly sprung front axle which we predicted may happen. Thankfully it’s an easy fix so we should start yielding gains with even more drivability.

A huge shout out to the NSW Prod Touring board for organising an awesome night and to the JJM Motorsport team for helping me out through the night - the motorsport community is truly full of wonderful people!