Bump for an update...Toda A/B/C or another brand + turbo?
Why don't more owners run cams?
- Thread starter L_RAO
- Start date
Hmmm might be adding to this later.
Full Toda C is going in my 3.6L now...
if it ever runs again... sigh
Measurements from Toda C cams can be found here: https://www.nsxprime.com/threads/camshaft-specs-and-measurements-toda-comptech.218245/
They're actually 252 degrees of duration on VTEC.
The web regrind profile is 235/230 advertised duration. Based on my limited knowledge the web profile is more suited to boost than N/A.
They're actually 252 degrees of duration on VTEC.
The web regrind profile is 235/230 advertised duration. Based on my limited knowledge the web profile is more suited to boost than N/A.
I might be doing a thing:
What would y
Very interesting! What would you do differently than the currently available options?
Custom cam blanks aren't limited by the dimensions of the OEM cams (which regrinds are) and the only company that really makes cams for the NSX is Toda, and their profiles are old and very modest/conservative by modern cam design standards. There is a lot of perfrmance to be had whether NA or forced induction with cams but the NSX market is too small for cam designers to consider, and there is not much info on cam timing since it's such a pain to adjust on the NSX outside of an engine Dyno.
Since my engine will be going on an engine Dyno, I am looking into having a modern cam profile made for the nsx and play with the cam timing on the C engine to see what kind of gains can be had... Depending on the pricing of these blanks that I will be quoting out. If it's too much then I will still get to test cam timing on an engine Dyno with the Toda Spec-As that I have.
Since my engine will be going on an engine Dyno, I am looking into having a modern cam profile made for the nsx and play with the cam timing on the C engine to see what kind of gains can be had... Depending on the pricing of these blanks that I will be quoting out. If it's too much then I will still get to test cam timing on an engine Dyno with the Toda Spec-As that I have.
Comptech cut their own cams (machined from billet stock), but I'm not sure if Shad can do that work anymore. ATR also cuts his own and currently offers several profiles that correspond to CT and Toda. You might want to talk to them, as they have a lot of data from ATR's race car and the Comptech/Acura Spice cars.
Comptech cams were hard welded weren’t they?. Hence the lobes cracking off the munched set I ended up with. Did they change to billets later?
Somewhat related, I don’t remember the company but there are VTEC killer roller rockers available for C30/H22 that could yield some interesting results.
Somewhat related, I don’t remember the company but there are VTEC killer roller rockers available for C30/H22 that could yield some interesting results.
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Cam design has changed and improved a lot in the past 20 years. I would be using a modern Honda-specific cam design.
Cams are far more complex than lift and duration alone. There is a lot to the rate the valve lifts off and sits back down into the seat, how hard it is on the springs, and the rate and when the valve opens and closes off of the seat. You can have a cam with a more conservative lift and duration be harder on valve springs and retainers and not have the durability or rev as high as a cam with a numerically more aggressive lift and duration. Since the majority of a cam is difficult to understand or quantify, it's often considered a "black-art".
Cams are far more complex than lift and duration alone. There is a lot to the rate the valve lifts off and sits back down into the seat, how hard it is on the springs, and the rate and when the valve opens and closes off of the seat. You can have a cam with a more conservative lift and duration be harder on valve springs and retainers and not have the durability or rev as high as a cam with a numerically more aggressive lift and duration. Since the majority of a cam is difficult to understand or quantify, it's often considered a "black-art".
The early ones definitely were hard welded. As part of the IEM package, you'd send your heads to CT and they would hard-weld and grind new VTEC lobes on the OEM MT cams as part of the service. Then, at some point between 1994 and 1999, they started cutting their own cams from billet stock. When discussing my engine plans for the Zero with Shad, he mentioned they would cut all the lobes first and then cut the keyway as the last step. It came up in the context of whether adjustable cam gears would make sense. Shad's point was that the keyways weren't always 100% exact and that slight variances occurred, making the cam gears a good solution. I stuck with the OEM gears since these cams made a proven 290 whp on docjohn's bumblebee, indicating to me that the keyway alignment was good on these particular units.
In addition, my CT cams are marked "6-99" and are clearly billet stock- there is none of the black nitride coating present on the OEM cams, which would still be there if just the VTEC lobes were being modified. So, they were making billet cams since at least June of 1999.
Here you can see the cams next to two of the OEM AT sticks- no nitride.
Also, they must have done some kind of surface hardening/treatment on the lobes because you can see here that despite lots of hard track miles on the Bee, the lobes show almost no signs of wear.
If Ken has your C engine dyno cradle done I might be able to bring mine out there. The tricky part will be the engine harness. Mine is currently stuck to on my car
I think there needs to be media on this! I (and the rest of NSX Prime I'm sure) would love to see a ITB NSX engine running on an engine dyno.
It should be going in pretty soon. How long are we talking about roughly?
There's a guy near me who I've been talking to about running my engine in on his engine dyno. Not sure if it'll pan out but playing with cam timing on it would be interesting for sure. Of course, last I talked to him was about a year ago due to various machining delays, so good chance he's either dead or closed up shop by now.
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I haven't looked into the actual step by step process of performing cam timing adjustments on an engine dyno but since i'm on the Toda C's, my fear is we screw up the timing enough where metal to metal contact can happen
