Thread: VE and Log Manifolds

so coheed it is ok to use a log type manifold once u are staying in the 400 to 450 whp range with the stock vvl head swap would this also be the same if the car is awd ?

You can make decent power with the log manifolds, as I proved with my setup. However, I did use the VET cams, as they made a LOT more power over the stock cams that experienced reversion. I have documented my experiences very well.

I now have my 20V cams switching at 4500rpm. It makes a slight audible difference, but the power delivery seems to be seamless.

VE head flows too well to have a flow disaster of a log manifold. Listen to Coheed he had a lot of first hand experience with this.

i cant wait to prove this theory wrong just so you guys can be like

It isn't the head design, it's the cam design. the stock VE cams I had caused reversion. Who knows... maybe I had SR16 cams in the stock motor...

But my experience left me scratching my head. If anyone can get a log design to work well with stock cams and a T3 turbo I would like to see it. If there is something I did wrong that can shed some light on all the issues I had, then it would def be worth documenting. But again... Vad had similar issues. Perhaps our builds were too similar?

Please do, and document it well, side by side dyno's and all.



What I meant about the head design is, by putting such a restrictive manifold, your negating the benefits of a VE head flow. But that is not nearly as bad as the cam overlap. Reversion seems to be the real issue, activating the cams made the car feel the same/worse. While I'm NA I can see what kind of difference I should have saw when cams activated.

Coheed you also had the newer revised version of the log manifold too. Yours should have flown the best out of all of the other logs we have for our motors. As for the cams, don't every cam have different colors?

Already been proven, even video of timeslips and mph to back it up. With what are considered to be sub-standar parts too, nothing expensive. Biggest single difference was a tuner.

Which is why I very highly suggest Lynch to get himself a tuner, prefferably one who is very versatile and does not tune one make only.

I still believe 100% in the reversion issues. A simple cam swap made ~110whp increase in power on the same boost level. I can't say others will see that kind of increase with VET cams and a log manifold. But you can see how bad the reversion was on my engine. My engine would bog bad.

Now Coheed both of us where running Protech log, I talked to Bruce and he did mention he uses SCH 80 piping for pretty much a bullet proof manifold. Perhaps other logs use sch10/40 and thus have a TON more space inside the manifold itself. SCH80 is the same size as the exhaust ports pretty much, so we do loose the anti-reversion effects that bigger ID piping would have against the exhaust runners.



Now when you guys do end up running logs, do you actually activate the cams below 5k rpm and make power? See a significant difference when the cams activate?

Perhaps the reversion issues we had are due to the power level we are operating at. For instance, reversion may not be an issue for 300whp. But what about 400whp?

Also, turbine size, compressor size, etc... all play a role in that.