hey guys.............
some issues i encountered while boosting my dc2r using avo stage 2 turbo kit...............
once it was all installed and ready for tune, i drove it to the workshop, had the injectors installed and ecu and onto the dyno she went..............
3 hours of tuning went buy and we had sorted out the low cam, with boost (8psi) the car made a healthy 145kw at 5000rpm..........
so next was for VTEC and boost...............
we found that once the car was on vtec and at around 6500rpm onwards it was making a wierd ticking noise from the head.....................so we stopped tuning, we couldnt figure out what it was and why, after another 2 hours of playing with the fuel and timing map......(we pulled timing out and gave it more fuel same sh#t)................the car eventually made 180kw at 7000rpm.............(we thought it was a spark issue)
so i was cruzing the car around for a week or so (to work and back, keeping it under 4000rpm) and decided to change a few things...............new dizzy cap, rotor button, spark plugs, new leads..........new vtec solenoid filter and fresh oil and filter............
so back for tuning and hopefully make some power..............
back on the dyno and a more precise map of tuning and away we went........same sh#t.................so i left the car there for them to figure it out.................
next day, the tuner and mechanics had a look at the car and discovered that:
it seemed as though on 8psi once the car got into the vtec range with only 20degrees timing and the correct fuel map, the car detonates its head off.................
the guys at the shop decided to trial and error........
so...............
by disconnecting the internal wastgate sirclip (that holds the flap closed unless the gate is opened by boost pressure) they gave it a run with the flap being held open fully...............the car managed to make a max of 2psi but no detonation at all............
then they gave the car 28degrees timing or so re-did the fuel map, and it again managed 2psi and made a healthy 170kw or so @ 7000rpm with everything going right...........
so the conclusion we have come to............
it seems as though the turbo's rear housing (garrett t28 roller with 0.86 rear exhaust housing) is too small, and is creating too much back pressure as it has a tiny rear exhaust wheel (not enough flow), which causes the exhaust fumes back into the head, which causes the detonation
now please dont get me wrong..........
im NOT slagging on AVO, as the guys there are great and helpfull........just giving you guys some info and a heads up if you own a b18c7..........and want to use AVO's turbo kit
from here, we are now presently about to strip the turbo and get a new bigger rear exhaust wheel put into it (high flow exhaust housing) and put it back together and see what happenes...............
i'll keep you posted.........
if anyone has any questions about the kit or anything related i will do my best to answer to the best of my knowledge/experience, otherwise i will not answer at all.
cheers
Tom
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