To V-tec or not to V-tec That is the Question"

xboost

New Member
Im getting ready to build a new engine and I wanted to turbo it, I've heard that v-tec and turbos work aginst each other, so my question is which would work better a B18 non v-tec turbo or a b18 gsr turbo??
i don't know that much about turbos what do you guys think
 

DownShift96GSR

New Member
People say that and it may be true, but if it is, why do so many people turbo VTEC engines? Rumor on the street is that the GSR engine is real friendly to boost. But you can go ahead and believe that a non-vtec turbo is better, but tell that to the people on the HONDATA website. There is a 647 wheel HP LS/VTEC on there. Or talk to HONDA TUNING who had a 10 second daily driver Teggy on the cover, GSR motor with TYPE R crank and head, 600 HP. Oh yeah and almost forgot, FULL-RACE.com who has a Civic Si turbo'd witth 616 WHP. Personally, I'd be pretty damn happy with those numbers.

Ok, sorry about the smart ass part. Now for the more technical part. Basically, the turbo cancels out the VTEC, they don't work against each other. The VTEC and the turbo are both made for top end, hence the reason the turbo cancels out the VTEC. Others argue that the VTEC helps the turbo spool by the fact it opens the exhaust valves for a longer period of time while the non-vtec does not have this feature.

That's the explanation as to how I understand your question when I asked about it.

edit: Yeah forgot something. Another advantage that the LS has over the GSR is the lower compression. But after you build your engine enough your gonna end up getting new pistons anyway. I say go GSR w/ turbo.
 
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Chuckie Finster

New Member
Stock VTEC cams are generally good for turbocharged applications. However, if you put in a set of hi-overlap, N/A VTEC cams the boost made by the turbo gets blown out the exhaust valves. The reason is because during overlap, both the intake and the exhaust valves are open at the same time. This is great for a hi RPM natural engine where it needs the "scavenging effect" (that is when the exhaust leaving the combustion chamber creates a vacuum) to aid in filling the cylinders with a fresh air/fuel charge. On a boosted engine, where there is positive pressure, the overlap causes the positive pressure to blow out the exhuast end. That said, turbo's love lift. That is--how "wide" the valves are opened. And because of that there are special VTEC turbo cams made with a lot of lift and only slightly more duration (how long the valves stay open). If you want to turbo a VTEC motor, stick to the stock cam or use a turbo cam and don't get an N/A cam.

As for which engine to get, it depends on how much you want to spend. The GSR/TR motors will cost a lot more in upgrading the valvetrain (uh, 'cause of VTEC) but they do make rediculous power. Personally I'd stick to the LS; it has slightly more displacment (more torque=more power) and can make just as much power. Whichever route both are great for boost and good luck. Keep us posted. 8)
 
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