rentonone

iTrader: (1)

ive noticed my boost is going upto 24psi in this cold weather, its been mapped to 1.25bar, should it be doing this? i was also told at a recent rooling road that the boost was spiking to 1.3. car is a my00

Trap2Terrorist

iTrader: (3)

Mine's mapped to 1.25bar but spikes to 1.33bar.

Neilo

yeah but 24psi is just under 1.6bar.....which is a little concerning.

rentonone

iTrader: (1)

what happens when the boost spikes? is fuel added to suit?

Neilo

nope. Its not something you want on a regular basis id say.

miltski

i was going to ask this, i've got an electronic boost controller and i thought ti should regulate the boost all year round, when i had it on the dyno i got knock at 1.2 bar, so had it set to 1.1 bar, but my max boost display is currently 1.19, so should i put the boost controller to a lower setting? sorry to hijack the thread rentonone. btw trap2terroist what power have you got running at that boost?

KenS55STI

Is the gauge accurate ? Have you hit fuel cut yet ?

Tidgy

if its a single spike it's not a major issue, mine has spiked at 1.7 bar on the defi (uk turbo my00) last winter, norm hits 1.4 max spike on the defi even in sub zero temps. its mapped to 1.2 ish bar (not sure what exacly)

however defi's are know to read slightly high, when i asked if it was an issue at the place that looks after mine, they said if its a single odd spike to 1.7 then wouldn't worry unless it starts spikng at that often.

miltski

the guage is the digital one on the boost controller. and fuel cut out has been adjusted, so haven't hit it yet.
i've checked today it has spiked to more than i want but the boost controller is pretty good at holding the boost exactly where it was set at, but to be safe i've set it a bit lower and tbh it still feels as quick so it'l probably sta that way

Tidgy

it will be boosting strong at the min cos of dense cold air. aka the air temps fairly constant rather than heat rising up from where sun has been on it, causing the car to take gulps of hotter there for less dense air in

LG John

1.7 car on a TDO4 Even as a once off I'd be ****ting myself at that. I remember I took a meaty spike to 1.45bar once in mines (normally 1.2) and I backed right off. I'm pretty sure a single spike to 1.7 could cause damage. Tidgy if you are regularly spiking to 1.4 bar I'd suggest you fit a dawes as IME it's better at holding your target boost. Better yet fit a 3-port solenoid.

Tidgy

i did, new pants please lol, athough it truth cos of high reading it wasn't hitting that anyway, but first thing i did was ask about it cos i was concerned and was told single spike will be ok. it hasn't done it since and survived so don't think its an issue.

tbh have been thinking about aboost controller like that just in case, know how much they are to have and fitted?

rentonone

iTrader: (1)

mine has already got a 3port boost solanoid and my boost guage is pritty accurate because it usually boosts to a tad over 18psi, its mapped to 1.25 bar which i think is roughly 18psi. the turbo is a vf35 with a ported wastgate to stop boost creep, its only started to overboost in this cold weather. So do cars still overboost a little even when mapped properly?

Tidgy

yeah can do, they have intelegant ecu's aka they slightly adjust themselves to the driver/weather conditions, a ecu reset should take it back to exactly how it was mapped

LG John

You'd pick up a dawes for £30 and fitting you could do yourself as there are plenty of instructions kicking around and it is easy

Tidgy

ahh righto, shall have a gander, tar

KenS55STI

ecus tend to have compensation tables for atmospheric pressure and temperature. How effective they are depends on how they have been set up.

miltski

i went out last night and got a peak boost of 1.3 bar, i'm sure i could hear/feel pinking on full chat in 5th(for about a second until i shat myself and slowed right down!), on checking the boost controller it was managing to hold the boost at 1 bar although it was overboosting initially, so i turned the controller down so the car would only boost to 0.9 bar, and although it peaks at 1.09 now i feel safer. should i turn the gain down on the controller as i think with the cold air the boost is coming in too quick for the controller to shut the wastegate and therfore i'm getting overboost?
any help would be appreaciated, also would fitting a front mount or larger top mount reduce the risk of knock?

miltski

anyone?

easyrider

Sounds like youre waste gate duty cycle needs tweeking down-Just lowering the boost level wont allways stop spiking-if the WGDC is too high(which will show up in the colder weather) it'll be bringing the boost in too quickly for the ecu to control the target boost.
You could also try changing the restrictor in the small boost pipe(the pipe on the turbo outlet nipple) to one with a slightly bigger hole-youve probably got a 1.1mm restrictor-try a 1.15mm.Sometimes that extra .05mm hole can make the difference, but you will sacrifice the spoolup a bit.

Gary.

miltski

cheers for that i was anticipating this problem when I went full decat but never ad the problem in the summer, will perhaps give that a try, i wont really miss the spool up if i loose a little, its VERY sudden when it does happen, if i full throttle in 1st or second i'll hit the rev limiter almost straight away, so perhaps the car will be a bit more driveable
cheers again!