Displacement factors

[honda#72]

So I had a idea and wanted to know what the rule was pertaining to displacement factors and mods to vehicles. A 25% factor is assigned to any vehicle with variable valve timing. If variable valve timing was removed/disabled/bypassed, would the factor still have to be taken. Do these factors related to how the vehicle currently is or how it was produced. I guess it would be similar to a turbo car removing the turbo and running n/a. Would that vehicle still have to take a 25% factor for the turbo that it was produced with, even though it no longer has one. The reason I ask is if I run "Vtec Killer" camshafts which eliminate the variable valve timing and electronic lift control, the car will no longer have variable valve timing, and I feel that in that case the factor should not apply.

Chris

[Rabbit Farmer]

It is is not on the car, the car doesn't have it for SP and P.

Unsure if this would be allowed in U

[walterclark]

Of course you cant make any mods in U but if the variable valve timing is removed (in SP) it should no longer count. It would have to be really removed or disabled so it clear that it cannot be activated or someone in your class might protest.

[honda#72]

The car was ran in Sp in its only event last year, and will continue to run in Sp. If the system was disabled by the "Vtec killer" cams, then I would remove the spool valve and vtec pressure switch which sit on the side of the cylinder head, they would just be dead weight at that point. I am not going to take this on until next winter as I don't feel like rebuilding the cylinder head this year again, as I just did about 250 miles ago, (rebuilt it before fall Ascutney, drove it there, ran it , drove it home and parked it.) "Variable valve timing" doesn't really help me now anyways, as the switch to the big cam lobe happens at 6,000 rpm. I have to keep the motor between 6,000 and 9,200 rpms during my runs because if I fall below 6k rpm during my run I fall off the big cam, and lose all my power. Not much goes on below 6,000 rpm on the first generation motor. A 87.0 mm bore and 84.0 mm stroke means not a whole lot of low end grunt. Thanks for the answer Walter.

[walterclark]

No problem. Of course I am not on the technical committee but I play like I am one on this forum...

Its like Don T. says: Updating and backdating within a model is permitted. and of course so are changes - or modifications. So one must consider what is true now and not simply how it was produced. For instance my '86 A2 GTI came with a 1.8 8v and I have updated it to the 2.0 16V from the 91-92 A2 series GTI. I have to use the newer engines displacement, multi-cam and more than 2 valves/cylinder awards because that is what I have now.

[Rabbit Farmer]

6000 and 9200 RPMs for usable range. I hear some 1st gear downshifting in your future. (crunch)

I set my redline for 6200 right now... might up it to the stock 6500 or 6700 RPM.

[honda#72]

Yeah, it's hard to stay near peak power (8,300 rpm), thru the tight sections. To avoid the urge to throw it in first on the tightest turns I rebuilt my differential this weekend and installed a 4.8-1 final drive over the stock 4.1-1. Should help the low end, but also will bring even more wheel spin (which was a bit of an issue even with stock power levels and gearing) and increased number of shifts. Although some times the wheel spin helps keep the revs up. Not to mention I'll be over 5,000 rpm at highway speeds in 6th gear driving to events, a few trips like that should motivate me to fix up the truck and buy a trailer soon. If I get the time to transfer my pics of the build to Flikr or something to that effect I will post them at some point.

Chris

[KevinGale]

.. and increased number of shifts. ...Chris

How many times do you have to shift at Ascutney? I'm kinda on the opposite plan. I found out I can run under 3 mins shifting just once. But when I really worked at it and shifted twice I got a bit faster.

[Rabbit Farmer]

Kevin... that is because you have something called "tark".

[Number_5]

I ran in third gear. Trans stuck in 3rd. NO SHIFT just a bit of clutch slip at start.
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John Marsha