My puny race
- AHTOXA
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My puny race
I don't street race much. Rabbits aren't fast and I generally have more sense than that.
Last night was a bit different.
I was standing at a light and this new Civic was revving at me. EX, V-tech.
We pulled from a light but he started a bit late. I had half the car on him when we left. I extended it to a car and a half by the time I let off. Wimpy but fun.
Last night was a bit different.
I was standing at a light and this new Civic was revving at me. EX, V-tech.
We pulled from a light but he started a bit late. I had half the car on him when we left. I extended it to a car and a half by the time I let off. Wimpy but fun.
'19 Toyota 4Runner TRD ORP
'12 Suzuki V-Strom 650
'12 Suzuki V-Strom 650
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- Senior Standardshifter
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Re: My puny race
AHTOXA wrote:I don't street race much. Rabbits aren't fast and I generally have more sense than that.
Last night was a bit different.
I was standing at a light and this new Civic was revving at me. EX, V-tech.
We pulled from a light but he started a bit late. I had half the car on him when we left. I extended it to a car and a half by the time I let off. Wimpy but fun.
V-tec not V-tech sorry lol...anyway nice killAHTOXA wrote:I don't street race much. Rabbits aren't fast and I generally have more sense than that.
Last night was a bit different.
I was standing at a light and this new Civic was revving at me. EX, V-tech.
We pulled from a light but he started a bit late. I had half the car on him when we left. I extended it to a car and a half by the time I let off. Wimpy but fun.
- VTECaddict
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Re: My puny race
VTEC not V-tec sorry lolNjSi wrote:V-tec not V-tech sorry lol...anyway nice kill
2006 BMW 330i 6MT
- potownrob
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Re: My puny race
he might as well have had a v-tech phone hooked up to his engine
ClutchFork wrote:...So I started carrying a stick of firewood with me and that became my parking brake.
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Re: My puny race
i guess his vtec never kicked in yo
- Bawked
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Re: My puny race
Yep guess he didn't hit the TEK or otherwise you'd be hearing that racing car fly past mang!
don't the newer cars ahve gay economy ivtec or sumthing tho? stupid they need to keep vtec aimed at ricers to dominate v8s...
don't the newer cars ahve gay economy ivtec or sumthing tho? stupid they need to keep vtec aimed at ricers to dominate v8s...
<3 fwd
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Re: My puny race
ivtec = vtec, only difference is ivtec can crossover at different rpms depending on what you want the car to do.
really tho, with how the 2 separate lobes vtec works, ivtec is sorta retarded. you gotta understand how they determine the best crossover point first before youll understand why
1. they set VTEC to some ridiculously high rpm, like 7 grand and make a non vtec dyno pull. they get the dynosheet from that
2. they set VTEC to some riduclouly low rpm, like 3 grand and make a VTEC cam pull. they get another dyno sheet from that.
small non vtec lobes are good for the bottom end, but up top they choke the engine down, so the power bleeds off as you get higher in the rpms.
contrary to that, high lift and duration VTEC lobes are good for the top end, but they are open too long and too high for the bottom end. think of a cammed V8 with an agressive cam. great top end and absolutely nothing down low and like 1500rpm idle just to stay running. therefore VTEC cam starts out shit weak and gains power fast as you climb the rpm range
you take the 2 dyno sheets that you got from the 2 pulls, lay them on top of each other, and then you can see where the non vtec cams start to lose power and where vtec cams start to gain power. where the 2 lines cross is your optimal VTEC crossover.
so you can see with this method, you will have 1 optimal vtec crossover point. if you set the crossover before that, you will engage the vtec cam at too low of an rpm and you will lose power in the midrange. if you set the crossover too high, youll be running on the non vtec lobe at too high rpms and choke the engine and lose midrange power.
so i vtec sounds like a great idea but its just another thing that doesnt really have to be there, regular VTEC will work just fine.
really tho, with how the 2 separate lobes vtec works, ivtec is sorta retarded. you gotta understand how they determine the best crossover point first before youll understand why
1. they set VTEC to some ridiculously high rpm, like 7 grand and make a non vtec dyno pull. they get the dynosheet from that
2. they set VTEC to some riduclouly low rpm, like 3 grand and make a VTEC cam pull. they get another dyno sheet from that.
small non vtec lobes are good for the bottom end, but up top they choke the engine down, so the power bleeds off as you get higher in the rpms.
contrary to that, high lift and duration VTEC lobes are good for the top end, but they are open too long and too high for the bottom end. think of a cammed V8 with an agressive cam. great top end and absolutely nothing down low and like 1500rpm idle just to stay running. therefore VTEC cam starts out shit weak and gains power fast as you climb the rpm range
you take the 2 dyno sheets that you got from the 2 pulls, lay them on top of each other, and then you can see where the non vtec cams start to lose power and where vtec cams start to gain power. where the 2 lines cross is your optimal VTEC crossover.
so you can see with this method, you will have 1 optimal vtec crossover point. if you set the crossover before that, you will engage the vtec cam at too low of an rpm and you will lose power in the midrange. if you set the crossover too high, youll be running on the non vtec lobe at too high rpms and choke the engine and lose midrange power.
so i vtec sounds like a great idea but its just another thing that doesnt really have to be there, regular VTEC will work just fine.
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- Master Standardshifter
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Re: My puny race
They also consider gas mileage as well. Even if you start gaining power at 3.3K with VTEC, if it's not much, the engineers will not want people losing fuel economy with VTEC cams. Also, VTEC has a different 'dis-engagement' point going down RPM than up RPM.
2007 BMW M240i 6MT
2006 Honda S2000 6MT (old)
2001 Honda Prelude SH 5MT (old)
2000 Toyota Camry V6 (old) auto
2006 Honda S2000 6MT (old)
2001 Honda Prelude SH 5MT (old)
2000 Toyota Camry V6 (old) auto
- VTECaddict
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Re: My puny race
VTEC school time. gather 'round, kids.
VTEC has a set VTEC crossover point. theres a "VTEC window" which can vary (raise) the VTEC point a little bit if you are not going WOT, and will delay switching back down so you're not constantly switching in and out of VTEC if you are sitting right at the crossover point, but other than that is a fixed value.
i-VTEC also has a set cam switchover point like old VTEC. the "i" is VTC (variable timing control), not variable VTEC crossover. VTC advances or retards the cam timing by rotating the camshaft with respect to the crank...like those adjustable cam gears tuners use, but electronically/hydraulically controlled and continuously variable with regards to throttle position and engine load (hence why they add on the "i" for "intelligent").
engines with a low crossover point (like my car at ~2300) do NOT have a high performance cam. under 2300 rpm, it runs in basically 3 valve mode with the 4th valve barely opening to create a "swirl" effect for more efficient cylinder filling/fuel atomization at low rpm, allowing for a leaner mixture and better economy. over 2300 rpm, VTEC switches cams to make it run fully in 4 valve mode in order to get adequate amounts of air into the cylinders at higher rpm. this is sometimes referred to as VTEC-E, but honda doesnt use that terminology anymore. my engine cover says i-VTEC just like engines with "real" i-VTEC.
and just to throw a curve ball into the mix, i-VTEC V6's do NOT have have VTC. the "i" in i-VTEC V6's refers to VCM (variable cylinder management), and is usually labeled as i-VTEC VCM on the engine. VCM shuts down 2 or 3 cylinders under low demand conditions to save gas. it uses the VTEC mechanism to switch to cam profiles that completely shut the valves (0 lift for the entire cam rotation) for the shut down cylinders, and is "intelligent" in that it can kick in at various rpm/throttle/speed.
VTEC has a set VTEC crossover point. theres a "VTEC window" which can vary (raise) the VTEC point a little bit if you are not going WOT, and will delay switching back down so you're not constantly switching in and out of VTEC if you are sitting right at the crossover point, but other than that is a fixed value.
i-VTEC also has a set cam switchover point like old VTEC. the "i" is VTC (variable timing control), not variable VTEC crossover. VTC advances or retards the cam timing by rotating the camshaft with respect to the crank...like those adjustable cam gears tuners use, but electronically/hydraulically controlled and continuously variable with regards to throttle position and engine load (hence why they add on the "i" for "intelligent").
engines with a low crossover point (like my car at ~2300) do NOT have a high performance cam. under 2300 rpm, it runs in basically 3 valve mode with the 4th valve barely opening to create a "swirl" effect for more efficient cylinder filling/fuel atomization at low rpm, allowing for a leaner mixture and better economy. over 2300 rpm, VTEC switches cams to make it run fully in 4 valve mode in order to get adequate amounts of air into the cylinders at higher rpm. this is sometimes referred to as VTEC-E, but honda doesnt use that terminology anymore. my engine cover says i-VTEC just like engines with "real" i-VTEC.
and just to throw a curve ball into the mix, i-VTEC V6's do NOT have have VTC. the "i" in i-VTEC V6's refers to VCM (variable cylinder management), and is usually labeled as i-VTEC VCM on the engine. VCM shuts down 2 or 3 cylinders under low demand conditions to save gas. it uses the VTEC mechanism to switch to cam profiles that completely shut the valves (0 lift for the entire cam rotation) for the shut down cylinders, and is "intelligent" in that it can kick in at various rpm/throttle/speed.
2006 BMW 330i 6MT
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- Master Standardshifter
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Re: My puny race
Ill stick with a turboed four, thanks.
- VTECaddict
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- Master Standardshifter
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Re: My puny race
No. Just a turbo for me.
And preferably an STi badge somewhere.
And preferably an STi badge somewhere.
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Re: My puny race
VTEC...Because every manufacturer has to come up with their special name for variable valve timing.