Mark Johnson

iTrader: (1)

RySmDPT14

With VVt cams the low med high and WOT base angle are changed. Often 0-4000 RPm is 0’d and from 4x to 6x it climbs 1-6 or 1-8 degrees through entire cylinder pressure range. With turbo applications I have found 0 all of the tables yields best results.

smokeshow

iTrader: (16)

That just means the cam isn't right for a turbo application. There are also gains to be had in spool time by adjusting the cam angles.

RySmDPT14

Ok what do you suggest for cam angles then? TSP spec’d the Cam and New Era Performance dyno’d the cam for best results. We ended up 0’ing the tables as the cam angles didn’t allow for boost to get over 5 psi at WOT. Spooling was horrible with anything but 0 in 2k rpm and up in 100kpa and up

randeez

would be interested in hearing any tuning techniques for spool time with the vvt, i search around a little to try and get an idea of what to do. searched on some import sites as well , i figured they've been playing with their own version of vvt for 20 years now but didnt find much

mine is prob considered a little lazy, it works in my truck just fine with the stall and gears though but theres always improvements that can be made

RySmDPT14

Totally spaced on the fact the cam was switched out for TSP VVt spec’d cam and I did keep VVt tables. From 4K to 6k it goes from 2 degrees to 6 degrees. Down low in cruise we 0’d the tables to maintain cam advancement

randeez

the tsp tables work good for NA and its pretty much what i had run for the past year, i just brought in the retard a little sooner and left the cells for cruising retarded/spark it just seemed to cruise smoother and tip in was better

what ive been looking for, and trying to understand about the import tunes - pretty much throws the tsp tables out the window. it looks like retarding the intake cam and leaving the exhaust cam alone or advancing it in the area you want to spool the turbo. we dont have that luxury with a single cam, so im not sure throwing abunch of retard at the cam in the area you want to spool the cam is going to accomplish much. also retarding the spark well into the combustion stroke, aiming for a 13:1 afr (to rich would cool the charge to turbo.) and this is all to be done while trying to spool the turbo, afterwards back off spark, richen mixture, etc. ive also seen where bringing the cam retard back to park position in the higher rpm. the thinking is - for an NA application the the retard should help with scavenging as you get closer to 100% VE, for boosted you dont need/want much overlap in the upper rpm. so you may be right as far as max power 0'ing the table in the upper rpm may yeild the highest numbers. but the cam retard tables somewhat like a plateau may yield a fatter curve

also have a cam from TSP, its 218/228 113lsa 109icl i recently swapped out the comp limiting block for the later style (smaller , allows more travel)

RySmDPT14

Retarding the cam in higher RPM allowed for the max power band to be carried past 5400 RPM, If I remember correctly when we tried going higher than 6 degrees there was too much overlap and we couldn’t get the boost to build past 4 or 5 pounds. It was like hitting a dead spot in the rpm band. At 4000rpm I start at 2 and at 8000rpm it stops at 6 degrees (have to look at tune to be sure)in my WOT vvt table (e78 ecu). On my ECU I don’t have the luxury of boost enrichment, so when tuning VVE table I maintain a leaner AFR in areas where I want to try and build boost and after I hit 3psi it richens up (per vve table). 1800rpm at 88 (map/baro) I keep it 14.0 and increase to my PE values that are set at the desired RPM-and throttle position . Yes there are times that I cruise on the freeway and it holds 3 psi at 14:1 at 25% throttle, but no detonation.

Jonblarc7

I’m putting the TSP stage2 218/226 in my L86.

I can’t get a straight answer on what the 0 out degree block does. Does it remove all the VVT timing. If it still does move how much.

randeez

i would imagine it doesnt allow the cam to move at all from the sounds of it? got a link to the block ?