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You can also shift pretty bloody quick; it seemed very stable and put down the power very well, what more for the suspension?
The tiny low inertia clutch makes fast shifting possible, and required actually as the revs drop almost instantly during shifts. The whole 5.5” clutch assembly weights just 13lbs vs near 60 lbs for a stock 9.5” street clutch/FW/PP combo.
The car accelerates very hard and there is a decent amount of weight transfer as a result which significantly unloads the front end both during straight line and turn exit. Chris wants to eliminate that. He has run the calculations based on studying the data a has decided to swap out the front tender springs with a pair that has a lower block load. We are also going to reduce the front shock Nitrogen pressure by 30psi to reduce the shock lifting force along with lowering the chassis another 5mm to lower the CG. All of this should address that deficiency. Beyond that we will be setting the car up for Michelins which may change the alignment requirements slightly. The car in its current alignment is set up really well for the Yokohamas but not so much so for the Pirellis which really need closer to -5 degrees front and -4.5 rear camber. The Yokos seem to be really happy at -4.5F and -3.8R camber.
Last edited by powdrhound; 08-16-2023 at 12:04 PM.
The car accelerates very hard and there is a decent amount of weight transfer as a result which significantly unloads the front end both during straight line and turn exit.
Yes, I could sort of see that in the video - I suppose that's a real issue with 900hp.
Makes sense - should be pretty flat when dialed in.
Kind of a techie post here. So the guys pulled the plugs out of the engine for a closer inspection to get an idea of the overall health of the tune and engine at this point prior to us running the 650, 700, and 750 torque maps. Johnny removed the plugs and put them under a microscope so Chris could take a close look. We've had these plus in the engine for 100+ dyno pulls and all the track work up to this point. As expected, the Bosch F08DDER racing plugs were in perfect condition across the board with nice even coloration. The engine seems very happy with these heat range 08 plugs. Details, details, details...Cheers...
Kind of a techie post here. So the guys pulled the plugs out of the engine for a closer inspection to get an idea of the overall health of the tune and engine at this point prior to us running the 650, 700, and 750 torque maps. Johnny removed the plugs and put them under a microscope so Chris could take a close look. We've had these plus in the engine for 100+ dyno pulls and all the track work up to this point. As expected, the Bosch F08DDER racing plugs were in perfect condition across the board with nice even coloration. The engine seems very happy with these heat range 08 plugs. Details, details, details...Cheers...
I would like to further this technical geek discussion and ask about how you have the handling of your car set up?
Do you favor a tad bit of understeer or oversteer, or completely balanced? Do you vary it from track to track?
We don't vary the set up from track to track. The car is set up to be very balanced. The idea is to have it turn in crisply and not exhibit mid turn understeer. It needs to power out of turns with a touch of induced oversteer if commanded. In the high speed sweepers we want the car neutral with maaaybe a touch of understeer. All of these characteristics change as the tires wear so it's a bit tricky to find the perfect balance. Handling also dramatically changes with different tire brands. While the car felt great on Yokos, it was pretty bad on Pirellis with much more understeer present. It's a bit of a black art to get it just right and that involves selecting the appropriate main spring rates and also they correct tender spring rates. The mains rates give you a good baseline (we run 400 lb stiffer rears than fronts: 2100 v. 1700) while the tenders allow you to fine tune how the car unloads in various situations. Shock tuning is split into high and low speed compression and rebound and that complete the package. I haven't mentioned sway bars, but we run the front 1 hole from full stiff and rear one from full soft.
Last edited by powdrhound; 08-19-2023 at 08:12 PM.
Meant to post this earlier but here is a cup and past from another forum regarding the dash along with some pics....
I had a few guys email me about this with some questions so I figured I'd post it up here as it may be of interest to some. During the course of a ground up rebuild on my car, Chris Cervelli and his gang installed the Motec C1812 dash logger. This replaced the C125 which was in the car before. Although the C1812 can be used with the car's factory ECU, Chris tied in the C1812 with the Motec M150 ECU and Motec PDM along with a huge array of sensors and other supporting bits and pieces like the Motec SLM (shift light module). We can monitor just about everything in the car from a systems standpoint including all the typical engine and gearbox parameters and on down to things like coolant pressure, steering rack pressure, exhaust pressure, airbox pressure, crankcase pressure, intake pressure and temp, fuel pressure and temp, etc, etc.. Chris wrote all the ECU mapping for this car and as such set up the car with anything and everything that he wanted in the process. We have not added shock pot sensors yet but have provisions for that when we get to it.
The C1812 with it's full with screen is a huge step up to the small C125 can essentially replaces the complete OEM dash. The screen is crisp and very bright making it easy to read even in bright sunlight. The close up pics of the dash taken below with my iPhone do not do it justice as they appear to be bluish while the background is actually black. Johnny at CTS used the Motec Display Creator software to design and configure the layout to our exact specifications. The layout is still evolving as we run the car and find things to modify or fine-tune on the layout from an ergonomic standpoint. We currently have the screen set up with 7 pages that one can scroll though with a push of a button on the steering wheel. This allows us to scroll though various diagnostic and set up pages including a page where we can switch between 10 different engine maps depending to torque requirements ranging from 300 to 750 ft.lbs. We also have a tire pressure / temperature page which is configured but not fully set up yet. This will allow us to see 16 temperature points along the whole tire carcass.
All in all, what you want to do or display with the C1812 is pretty much limitless and the amount of data the car collects if equally impressive. We pull approximately 150Mb of data from the car after every 30 minutes of track time. We typically pull the data with the Motec M1 software and open it up in Motec I2. The M1 software is more engine / systems oriented, the I2 software is more track data oriented although both largely overlap as the same/similar data is contained in both. In any case, I'm very impressed how the whole C1812/M150/PDM package integrates together and allows one to not only monitor the health of the car but also serves as an invaluable teaching tool with it's track data analysis.
For the gearbox, drive shafts or something else...?
Not from the standpoint of breaking anything. I just said I’m scared jokingly. Things happen awfully fast in a 2800 lb car putting 600 ft.lbs / 860 whp to the ground. At 750 ft.lbs / 1000 whp, they will happen that much faster.
Last edited by powdrhound; 08-21-2023 at 06:04 PM.
08-16-2023, 11:57 AM
