Project Casper AU / G&D – A New Evolution

[Casper]

Well, the data is back from this first stage of the project and it’s looking good. In fact, if you drive the car, the changes are remarkable to say the least. In this story the dyno doesn’t tell all. Not even close. The change will only truly show on the track.

So what is the story?
The story is simple; I want to make my car the best it can be. That does not just mean fast ET’s alone, that is almost a side effect. What I wanted was to make it a reliable, drivable and a very quick “streeter”. Something I can take to the track, race all night with good ET’s and without it missing a beat. Something I can give to my wife and know she could easily drive to the shops and back safely and reliably while I could do the same trip destroying the rear tyres with the same reliability if I chose. Something that is beyond just another modified Falcon running good times. It has to run GREAT times (in the end) but at no cost to reliability or drivability. To do this you need a car that is done right from the beginning. No patchwork modifications. Shortcuts like dumping out weight, removing suspension components and basically making it a “track only” car is not an option. It’s a road car first and foremost and has to stay that way.
So what was done and why?

The first thing that was done was Glenn at G&D and I discussed exactly what I wanted and what was achievable. Before we even started I wanted a stage by stage buildup, from scratch, to get to what we wanted. The order of modifications by stage was Glenn’s job and I have, to a large extent, deferred the product and order of work to G&D’s control. This is not to say I don’t know or have a say in it, I simply am letting them follow the “roadmap” we first set out. Professional, planned and precise. This is what they do best and I am very happy to let them do it.

Anyhow, this stage of modifications was simply to create the base on which to build. All the “usual” modifications were looked at and discussed. The airbox (as everyone already knows) was the first thing to go. A smallish pod stuffed into a stock airbox with PVC pipe feeding it air is as far away from “intelligently engineered” as you could expect. It had to go, and did, within a few days it was tested, replaced and the results shown (and controversial to say the least). In doing so we also found potential to get even more power from it but that’s for another time.

The next modification was to do a full flash edit to replace the aging Chiptorque. While the Chiptorque did its job well (and will continue to work on in another car on the Forums) it was simply outdated. Off the shelf tune, difficult to get custom tuned and “visible” if looked for, it was outclassed in every way by the edit. Therefore we made the decision to edit the car and see what was there.
What we found was that the car didn’t really want to respond all that well (in fact hardly at all). It seemed to reach a limit and then go no further, like it was restricted. We took a guess it may be the exhaust.

So the exhaust came off next and was replaced by a set of the new design Pacemaker 4480’s. This new design certainly seems to have addressed the VCT issues of the past and, with the larger pipe size, higher rpms are not restricted.
Of course, with the removal of the headers the different lengths from the old headers to the new left a bit of a gap. A big gap actually. Initially we were just going to flange in a collector pipe but, in keeping with everything else (and knowing we were going to replace the muffler and cat anyhow) it was felt a “mix and match” exhaust wasn’t going to cut it. So we replaced the entire thing.. more times than I can remember. First set was a great set with all the right specs but, when fitted, didn’t quite line up to tolerances we wanted. Off it came, back it went and in went a different setup which was “almost but not quite” as well So the only option left was to get one fabricated to G&D’s own specifications and that’s exactly what we did. Basically the same sort of setup a the regular G&D cat back for I6’s but up a few notches in maximizing performance (I’ll let Glenn explain it, he’s better at that stuff) The whole exhaust from the collector back was designed to maximize the flow of exhaust gases at high rpm. The muffler and cat on this new G&D system is the same, maximized for high rpm flow of gasses.
So with a totally new exhaust system the edit was then totally retuned to suit the new setup and the gains were there again. The exhaust suited the application better, simple as that.

Final result was 136.2rwkw.

On the dyno I wanted as close to an unopened 145rwkw as possible. That’s right, it’s still unopened. No cam, no adjustments to cam timing, nothing. The rocker cover remained in place. In hind sight is probably was a little much to ask, as Glenn had pointed out from the start, and I am very happy with 136.2rwkw as a good base to continue with. Strangely enough if the car still had a standard converter or was a manual the 145+rwkw mark unopened was their for the taking as far as we can tell. The Histall absorbs major rwkw (probably close to 10rwkw over the stock converter) however that’s the price you pay for a great launch off the line.
So in the end the car rolled into the G&D workshop with 119rwkw (probably closer to 125rwkw if the Chiptorque chip had been left in) and left with 136.2rwkw. No NEW modifications were done, we simply updated the existing ones with newer, better performing items. Airbox to replace the “pod in a box”, Edit to replace the Chiptorque and Pacemaker 4480’s, hiflow metallic cat and full custom G&D 2.5”/3” exhaust to replace the race headers, hiflow ceramic cat and redback 2.5” exhaust. End result is a considerable 11.2rwkw improvement over the estimated 125rwkw it started with. 136.2rwkw on a stock cam with the histalled auto.. and a torque figure that is closer to what some V8’s have, really is a credit to G&D’s product and tuning.


This sort of improvement may not seem like all that much but as I said, the difference cant be shown on the dyno as well as it can be felt. While starting off at similar rwkw at around 3500rpm, the power now comes on VERY hard and fast all the way to 5800rpm where the auto is now changing. This immediately puts the car into the powerband for the next gear and it climbs at a fantastic rate as well. More importantly the torque figures are massively improved now. While peak torque in the old setup ah peaked and started a slide back down the new setup is still climbing to a much higher level, stabilizing and then dropping off at a similar rate but MUCH later in the power band. The difference is “feel” is poles apart. Where it used to feel like it was just losing all the power up top, it now just keeps wanting to power through to the 5800rpm change point with no loss of urgency .

Anyhow, as I have said, this is just stage 1 and is simply to get the car into a position to move forward again, a New Evolution so to speak. Soon enough we’ll go the next step and try to get stage 2 done before the end of winter. Stage 3? Well, that’s still a little way away but give it time, it will happen. Until then I’m just going to go have some fun with her.