i have a few questions regrading my bulid up on an ls vtec in my 93 ls integra. this is my first ls vtec build and i want everything done right the first time so any info would be great. my questions are as followed:

1. i am using my stock ecu so i know i need a knock sensor but my question is this. what is the knock sensor wired into after it is threaded into the block?

2. what needs to be done (if anything) to my ecu for vtec to work and is there anything i need, electrical wise to successfully complete this.

3. with a stock internal block and a basically stock head with bolt ons, (header, intake and manifold, throttle body, cat back exhaust, fuel rail and regulator) should i have it tuned or have people seen optimum performance right out of the box with this, i figure this is a pretty common setup so thats why i ask. i know if i need a tune i will need a chipped ecu at the least or a piggy back style ecu.

 

You should always tune an LSVTEC.

It is not a stock Honda motor no matter how many stock parts you make use. A factory ECU will run it but will not do a good job. Spend some time getting it dyno tuned.

 

You should not use a stock non-VTEC ECU to control a VTEC engine. There are many sensors that come into play when VTEC is concerned, and it's best to run a VTEC ECU along with some kind of provision to tune and dial in the fuel maps. P28 SOHC Civic ECU's are popular to start with, since it has provisions for VTEC, and doesn't have the crazy IAB stuff like GS-R intake manifold do.

I would read up on this how-to if you want it done right.

https://honda-tech.com/forums/all-motor-naturally-aspirated-44/how-build-%22reliable%22-lsvtec-b20vtec-1676914/