Boost Control

[Turbo 33]

do u think it will make any difference if i run my boost controller line from the cold side of the intercooler rather then the hot side ?

like it on the pipe that come straight from the turbo now but the car feels laggy

will it be better if it is on the cold side of the intercooler

like the boost doesnt come on strong just feels shit tho it still says it boosting just doesnt feel like it

btw only mods are full exhaust fmic pod filter

EDIT HOPE THAT MAKES SENSE!!!!

Edited September 30, 2009 by Turbo 33

[gotRICE?]

There will be a marginal pressure drop over the Intercooler core, so having the Boost controller after the intercooler, should in theory be more accurate to what the engine is receiving.

For example (example only, if there was a 2psi drop over the Intercooler)

You set your boost at 14psi, and take that reading via the hot pipe, plumbed BEFORE the intercooler.

2psi Drop through the core,

Engine receives 12psi.

Compared to:

Controller set to 14psi, plumbed AFTER the intercooler.

The turbo would spin up a sneaky 16psi to create 14psi after the core, as the vac line to the actuator wouldnt see the full 16psi because of the pressure drop.

Engine therefore recieves 14psi, so would feel quicker.

Make sence? I could be totally wrong, but thats how i perceive it!

[Benzino33]

makes sense to me

[geraus]

yep yep

[Turbo 33]

so it will be better to have it on the cold side ??

and why does my stock turbo feel laggy??

and with that pressure drop will it be more if my intercooler is a bit bent at the top and bottom (that happened when my car got towed) bent the like have the bottom row so it now like have the size it would normally be and the same at the top

[paulr33]

as close to the compressor outlet as possible is the preferred method

this minimisses losses across the core and pipework etc

if its laggy it could be a million things

has it always been laggy, whats changed recently

has it had a service? what tune? what mods?

blah blah etc

[Turbo 33]

full exhaust fmic pod filter

stock computer

yes it has had a service every 5000

its been laggy since about 2 days after i fitted the intercooler

tho it was great for the first 2 days now shit and its been nearly a year there is no boost leaks nothin

its like laggy but just feel like the power is there but like lack of it and it doesnt have that boost feel tho it says its boosting

[gotRICE?]

Could be RnR too?

[Turbo 33]

Could be RnR too?

would that make the boost feel really flat sorta like its not coming but it really is

[mad082]

There will be a marginal pressure drop over the Intercooler core, so having the Boost controller after the intercooler, should in theory be more accurate to what the engine is receiving.

For example (example only, if there was a 2psi drop over the Intercooler)

You set your boost at 14psi, and take that reading via the hot pipe, plumbed BEFORE the intercooler.

2psi Drop through the core,

Engine receives 12psi.

Compared to:

Controller set to 14psi, plumbed AFTER the intercooler.

The turbo would spin up a sneaky 16psi to create 14psi after the core, as the vac line to the actuator wouldnt see the full 16psi because of the pressure drop.

Engine therefore recieves 14psi, so would feel quicker.

Make sence? I could be totally wrong, but thats how i perceive it!

the theory make sense in 1 respect, however it completely ignores something more important. the pressure that the turbo is actually running at, especially on a stock turbo. if you happen to have a restrictive cooler and have the boost gauge and controller after the intercooler then you might think you are only running 10psi but the turbo is actually running at 13 or 14psi and shortening its lifespan. also if the intercooler happens to get a leak of becomes blocked somehow, you are going to be increasing the load as the turbo isn't taking into account this problem and has to overcome this as the pressure is controlled by the pressure after this problem.

ideally you should have both the boost gauge and controller before the intercooler as this way you know what the turbo is running at. the engine isn't going to be recieving pressure any higher than this so you don't have to worry about anything there. however having the boost gauge anywhere before the throttle body will not show vaccum, which can often be good for diagnosing problems.

if i got another turbo car i would be running 2 boost gauges. 1 before the cooler, and 1 in the plenum. that way you can see what sort of pressure drop the cooler has and also vaccum.

Could be RnR too?

it wouldn't be affecting spool up though.

might be worth checking your timing. if it is a bit retarded from what it should be then you can get later spool up and it can feel a bit sluggish.

[Turbo 33]

the theory make sense in 1 respect, however it completely ignores something more important. the pressure that the turbo is actually running at, especially on a stock turbo. if you happen to have a restrictive cooler and have the boost gauge and controller after the intercooler then you might think you are only running 10psi but the turbo is actually running at 13 or 14psi and shortening its lifespan. also if the intercooler happens to get a leak of becomes blocked somehow, you are going to be increasing the load as the turbo isn't taking into account this problem and has to overcome this as the pressure is controlled by the pressure after this problem.

ideally you should have both the boost gauge and controller before the intercooler as this way you know what the turbo is running at. the engine isn't going to be recieving pressure any higher than this so you don't have to worry about anything there. however having the boost gauge anywhere before the throttle body will not show vaccum, which can often be good for diagnosing problems.

if i got another turbo car i would be running 2 boost gauges. 1 before the cooler, and 1 in the plenum. that way you can see what sort of pressure drop the cooler has and also vaccum.

it wouldn't be affecting spool up though.

might be worth checking your timing. if it is a bit retarded from what it should be then you can get later spool up and it can feel a bit sluggish.

ok what i should have said is it feels laggy like it spools quick and early tho doesnt feel like there is any power there i had the timing belt cover off like a couple of months ago and harmonic balancer was lined up with the right mark and the exhaust side was lined up as well but the intake side was off like its ment to be facing 10 oclock but it was alot closer to 11 but the other 2 were perfectly lined up could that affect power ??

[mad082]

when i was talking about timing, i wasn't talking about the cam timing but the ignition timing (although the cam timing being out could also affect things if it is out). if the CAS (crank angle sensor) isn't in the right spot then the ecu will be firing the cylinders too late and not making as much power.

with the intake side being out a little bit, would it be out by enough to be equivilant to 1 tooth on the belt?

[Turbo 33]

when i was talking about timing, i wasn't talking about the cam timing but the ignition timing (although the cam timing being out could also affect things if it is out). if the CAS (crank angle sensor) isn't in the right spot then the ecu will be firing the cylinders too late and not making as much power.

with the intake side being out a little bit, would it be out by enough to be equivilant to 1 tooth on the belt?

i dare say so maybe even a little bit more

could that stuff it up much ??

and what i ment by laggy it more feels NA rather then turbo like it still has power but lack the push back in ur seat feeling lol

but i can still hear the turbo spool and everything and there is no boost leaks

[mad082]

if the intake timing is out by a tooth on the belt, then that could certainly have an effect on things. it could mean that it isn't getting as much air/fuel into the cylinder as it should, so will be making less power.

[Turbo 33]

if the intake timing is out by a tooth on the belt, then that could certainly have an effect on things. it could mean that it isn't getting as much air/fuel into the cylinder as it should, so will be making less power.

also how did that happen then could it of jumped a tooth or something ?

is it a simple as just sliding the belt off then lining it back to the right stop and putting the belt back on ???

[paulr33]

i cant believe you put up with it for a year haha

[Turbo 33]

ok the intake side is not 10 oclock its more 9 oclock one tooth on the belt how do i fix that do i have to take the whole timing belt off

EDIT ITS 2 TEETH

Edited October 2, 2009 by Turbo 33

[mad082]

i don't know if you will have to take the belt the whole way off. i would assume that you would only have to slip it off the intake, turn it to the right spot then slide it back on. so you may just need to loosen a tensioner or something like that (not all that up to speed on the actual installation of timing belts)

being 2 teeth out, that's a decent amount, so you should notice some definate improvement in how it drives when you get it sorted, LOL.