Ive seen a lot of info from you guys about log manifolds and tubular ones.
The car originally came with a tubular manifold, then i put a log manifold on. My vtec is set to 4500 rpms. Keep in mind my redline is only 7500rpms.


Question is
Is Vtec set to low?
Pro's and cons of logs?


Specs:
Log Manifold
gt2860rs
2.4l oem stroker

 

LOG = not efficient...I want to sell my log cause I maxed it out

 

what turbo did you make 478 with?

 

can u elaborate a little more?

 

VTEC and redline are both too low. I've never seen a log with a lower than stock VTEC point that didn't lose power. Sounds like your tune is still setup for the tubular manifold. That's not a good idea. The fuel curve can change significantly and log manifolds are typically a bit more knock happy...

Tim

 

Well Equal length tubular manifolds are effectively just that! Each runner is the same length reaching the turbo which means for each stroke of the piston, the exhaust gases have an equal volume or length to escape into. It is said that the runner length is often desired to be about the volume or length of the stroke of the motor to allow exhaust gases to easily escape.

With a log manifold, this area is generally much smaller, and more often than not, the turbo is placed in closer proximity to some cylinders than others which in "theory" causes some cylinders to be "driving" the turbo more than others. The log also allows exhaust cases to in a sense just "crash" into eachother without any guidance or flow into the turbo

With all this scavenging and inefficient exhaust gases on a log leading to the turbo, it usually creates alot more heat (leading to earlier detonation) and takes more boost to reach a power goal when compared to an identical setup than a equal length tubular manifold.

 

The redline is low because its a 2.4 oem stoker kit. These bearings cant take more then 8k..The turbo is extremely small for what im running right now so the rev limit was lowered so the turbo would stop dumping off power at 7000+rpms. The problem is, i dont have this motor in an s2k, and dont see how i could manage to fit the tubular manifolds you guys run, w/out having numerous types to fit and play with.

The redline has only been dropped 1k from when the tubular manifold was on.

 

Put whatever tubular manifold you had back on.

I went from a greddy kit to a mase kit.

I made 130hp more on a 100 degree day vs the 52 degree day i tuned my greddy kit on the same dyno. Also 11psi on greddy vs 13psi on mase. Tu ular makes way better power

 

No question that tubular makes better power but, your not going to say you made positive gains in power because of the temperature and the type of manifold when comparing a greddy kit and a mase kit. The mase kit is like double the price of the greddy kit and has a standalone ems

"it ain't the same game, it ain't the same ballpark it ain't even the same facking sport"

IMO whether you go tubular or log is entirely up to what your trying to do. LOG's are cheaper and yea they probably max out, but people run inlinepro stage1 kit's to like 500whp and thats with a log manifold.

If it's a question of space logs are smaller and fit into tight spaces. Tubular one's can be crafted to fit where ever you want really but it's gonna cost you.

In summation LOG manifolds aren't bad they just serve a specific purpose. If you dropped some power when you put the LOG manifold on then change it back again you said you had a space issue because it isn't in a S2K

Inlinepro's log manifold is solid.

 

My manifold is just like the inline pro one. Its an off brand but havent had fitment issues, and the design seems to be pretty sufficient.
The manifold that it came with was a DC Ram horn manifold. Yes it was DC. Its been welded and cracked, and track side welded, and cracked, so on and so on, so many times its useless now. If you look at my build thread on the first page or two you'll see the manifold.
I plan on running a gt3071 in the future and dont plan on making anymore then 450-500hp one day. Im only shooting for 300 now.
Im having a very reputable tuner on this soon, im sure he will be able to crank this out.