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Thread: VTEC vs SVTF variable valve timing Reply to Thread
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Topic Review (Newest First)
08-28-2004 10:36 PM
steedazx5 throw that motor out of the rsx type s into a hatch and ba, 12 sec rliable daily driver.


thats what i plan on doing soon.

ill find a front clip and get some rsx parts like seats lil stuff throw it on a 2000 hatch
07-20-2004 02:08 PM
007
Quote:
Originally posted by electric turd
007, I work for acura, I have a Q, why did you get rid of the rsx?
Because I wanted a smaller car payment, something more practical (a four door instead of a two door coupe with useless rear seats), and I hated the RSX. Initially I wanted an 04 ZX5 PZEV with a manual transmission but that was impossible to find, so the SVT ZX5 became the next logical choice. I'm happy I never got the PZEV because the SVTF is simply a better car, even with the premium gas requirement. And, it was cheap. I got the car for invoice minus the $2,500 rebate offered by Ford.

This SVTF is easily the best car I've ever owned. I love driving it every day more and more.
07-20-2004 06:40 AM
electric turd 007, I work for acura, I have a Q, why did you get rid of the rsx?
07-20-2004 03:02 AM
007 The VCT system for the SVTF provides for emissions control and better midrange throttle response, but it sure didn't do jack for gas milage. I don't miss anything about my RSX Type S except for the excellent gas milage. Consistantly no less than combined 24 mpg, and that is if I was flogging the car. Driving in a more sane manner I was getting between 26 and 27 mpg in mixed city/highway driving. Driveline thrash in that car was terrible though, but the gearing was spot on. The first two gears in the SVTF are all wrong, way to tall. If you don't give the SVTF enough throttle from a dead start this car behaves like a turbo charged car, it bogs initially and then once it hits about 3K rpm takes off. I know my clutch is going to die early in this car because I'm constantly having to slip the clutch at 3K rpms just to get the thing moving in traffic. A/C and a very tall first gear make the SVTF a complete dog in stop and go traffic.

I have to give it to Acura, the engine in the Type S is a thing of beauty. Amazing gas milage, bulletproof reliability, 8100 rpm redline, and 200 hp/142 tq out of two liters. I think the folks at SVT did a great job with what they had to work with. Another 30 hp and better first and second gearing and the SVTF would have been a real hit, I'm sure it would have sold much, much better than it did. It would have been more expensive, but I'm sure people would have paid.
07-19-2004 08:48 PM
03Z_ex_Three Anything electrical is not reliable.
The zetec has no adjustable cam timing, only the svt (intake) and the zx2 (exhaust).
07-19-2004 08:24 PM
Sonic04SVT Best description of the SVT's VCT I have seen is here: http://www.myfordfocus.com/svt/

Summary:

Quote:
The intake camshaft is equipped with an electro-mechanical control mechanism, which allows the camís maximum opening point, relative to crankshaft degrees, to be varied between 85 and 145 degrees after top-dead-center on the intake stroke. The variability is dependent on engine speed and load, and is accomplished by changing oil pressure on either side of a piston in a helix between the cam and its drive pulley. This is the first application of variable intake cam timing at Ford in North America, and is a significant contributor to the engineís remarkable low-end torque.
It's totally different then the VTEC, think of VCT more like adjusting cam gears to retard/advance the cam timing, rather then the VTEC's seperate camshaft lobes for differing RPM ranges.

I have to give it to Honda, the VTEC is actually a great idea because you can have the low RPM cam profile and the high RPM cam profile so you essentially have 2 motors in one. The SVTF's VCT is also a good idea, however your just altering the cam timing more then anything else, benefitual but not as significant.

The REALLY COOL THING though will be when there are e-valves (electronically actuated valvetrain) where you forego a camshaft entirely. You can then have as many different cam profiles as you want, meaning every load, RPM, throttle position, weather condition, air temperature, whatever you can think of..you could have a perfectly matching cam profile for it. Probably will make tuning a pain...but you could have added power, economy, driveability, with lower emissions. Rumor is Ford has worked on such things for some time now show very significant gains, but were having difficulty making it reliable.

Keep in mind camshaft selection only plays part of the role in determining the engine's performance, intake runner length and exhaust style/runner length also determines where an engine makes power, but imagine a e-valve engine with a variable runner length intake...it could be a crazy engine combo.
07-19-2004 12:48 PM
Beantown Focus http://auto.howstuffworks.com/question229.htm
07-19-2004 11:07 AM
SVTF'nGR8 VTEC is actually quite an ingenious thing from what I have learned about it. Indeed it is a sort of trick to get the best of both worlds: a smooth idle with high lift/duration at RPM. It is controlled by the engines speed and throttle position sensors which tell it's computer which of (3) cam lobes (PER VALVE MIND YOU) to initiate. As RPM's climb, the sensor will activate an electronic spool valve which directs oil pressure to a mechanical pin which slides & actuates the valve to the follower on that RPM lobe. (again 1 of 3 intake and exhaust) A crutch, hardly. It is a very real, simple function to almost instantly change the valve timing and thus the engines powerband.
The true VTEC is only found on the DOHC motors, the SOHC civics with VTEC do not have extra 2 exhaust lobes because of the lack of a 2nd cam.
07-19-2004 10:27 AM
CivicHatch+SVT-F All i know is that when Ron hits vtec in 1st and 2nd and can bark his tires mid-way through his RPMs then that would seem to me to be a nice lil power increase

"Zetec doesn't have an "h" in it either..."

oops! blonde moment
07-18-2004 07:39 PM
DeltaT
Quote:
Originally posted by CivicHatch+SVT-F


please research before you post. Theres a big difference between the two. Ever been in an H22 hatch with all the bolt-ons? No? Ride in one of those and tell me Vtec doesnt give you more power after the crossover.

Vtec (no H) = Variable Valve Timing and Electronic Lift Control
Zetech = thats just the name of the engine itself
The Vtec is a crutch. It allows the car to run with a valve timing at high rpms that would barely allow the car to idle. So Vtec doesnt really give you power, it more gives you a smoother ride at lower engine speeds. If that makes any sense.

Kurt
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