I don't really understand what we'd be doing.

I estimate 1 car-length for each 0.2-0.3 of a second in a 1/4 mile. That's the way it seems to be compared to stock. SC S2K = 4-5 lengths by 100 MPH. I would assume that Derryck would be 4-5 lengths in front of me if he's running 12.1. So that's about 7-8 lengths on a stock S in the 1/4.

 

>> I don't really understand what we'd be doing. <<

Basically, just going from one speed to another in a given gear while timing it. You might be at say 35 MPH in 4th gear and then floor it, timing between say 40 and 60 MPH. Gadgets can do this for you but a stopwatch is fine, especially in the slower accelerating higher gears.

>>I estimate 1 car-length for each 0.2-0.3 of a second in a 1/4 mile. That's the way it seems to be compared to stock. SC S2K = 4-5 lengths by 100 MPH. I would assume that Derryck would be 4-5 lengths in front of me if he's running 12.1. So that's about 7-8 lengths on a stock S in the 1/4.<<

I'm not suggesting doing a 1/4 mile. That basically occurs totally in VTEC, say 6000-9000 RPM. And skill, luck and a hard launch are required to do well.

I'm trying to suggest some easy repeatable tests to highlight the large differences between the two torque curves. The differences are great above the stock vtec RPM. But even GREATER below that point.

That's why I suggested doing the higher gears. Different rev ranges will be utilized in that case. No hard launches are involved, not even any shifting, unless you try to replicate SCC's 15-100 MPH test. This type of test highlights what some call elasticity or flexibility. It's up to you guys of course. I do these sorts of test all the time to test parts and see what is going on. It's very effective.

Stan

 

Forgive the ignorance, but what does the Apexi V-AFC do exactly? I've seen it mentioed quite a bit, the best I can assume is that is controls the VTEC to a certain degree. Does it make sense to have one on a N/A car too? What is the purpose of coupling it to a turbo or S/C equipped car?

Thanks y'all....

 

The V-AFC does or can control VTEC engagement point but it also allows to map fuel. Yes, there is a benefit for it's use on an NA car. Most have gained somewhere in the 5-6 hp neighborhood I believe by installing and tuning the V-AFC. With FI, it allows you to change VTEC and add or remove fuel where needed throughout the rev range.

 

Thanks! One more question if you don't mind. Are there pre-mapped sequences built into the machine or would the user have to program the right mix througout the engines powerband? I assume it works in 250 - 500 rpm increments? Seems kinda dangerous in the wrong hands if one would have to program it! It looks kinda cool too.

It seems like a useful tool, especially for N/A folks with larger throttle bodies, exhaust systems, filters, or other mods that affect an engine's breathability.

Thanks again.

 

[QUOTE]Originally posted by E30M3
[B]I'm not suggesting doing a 1/4 mile.

 

The two NA applications I know of gained 11 HP and 12 HP.

Hiro, in addition to peak HP, a smoother power curve is supposed to produce results if measured on the track. VAFC does a good job smoothing out the power curves.

 

I gained more as well, I was keeping the numbers modest so some of the 'nay-sayers' on this forum wouldn't jump all over it.

 

Yeah Derryck. I'm thinking that FI applications could get up to 20-25HP. I'm curious what you got?

 

We didn't do alot of tuning after turning up the boost but my original dyno at about 4 psi with no tuning was around 227 RWHP and after tuning we were at 260+ RWHP. So it obviously made a substantial difference.