possible boost leak?

[gtir bean]

is it normal after fitting a front mount to loose some boost if nothing else is changed?i was running 1bar with the top mount using a bleed valve and not going thru the standard boost solenoid but now with front mount i get about 0.7 to 0.8 bar.i cant see anywhere it will be leaking but is this just normal or do i need to keep looking?

 

[jpward]

Different coolers have different amounts of pressure drop due to design but longer runs and a bigger cooler in the system would create a slight drop though FMIC will have cooler charge temps just reset up to 1Bar again on bleed valve.

 

[gtir bean]

thats what i was going to do but just wanted to check if others had the same sort of thing after fitting a front mount.

 

[deslynam]

Yes it does happen, there's an interview in this month's J-Tuner magazine with the owner of Forge and he mentions it.

 

[Fast Guy]

I didn't notice any loss of boost after fitting my forge front mount. It is quite normal for it to happen tho.

Does the car feel slower than before/faster or the same?

 

[gtir bean]

feels a little slower but it is running less boost than before.

 

[jpward]

just out off interest did you remove the small pipe that runs from the plenium to the bottom of the IC bracket?

IT has a small restricter in it and will lower boost when removed!

best for you to connect into it with a straight connector to the bleed valve some guys on here have lost power on here just by removing it!

 

[Stoned]

I lost 3psi from fitting a front mount on mine, but not 0.3 bar!

I didnt really notice the power less as the extra power from the FMIC helped bridge the gap, and the rest I made up with the boost controller.

 

[gtir bean]

i just took the metal bit off the ic bracket as i dont have a bit of pipe long enough to remove it so everything is the same as it was other than the cooler.

 

[jpward]

Humm still a fair wee drop you could try looking up the spasific pressure loss on your cooler usually thats listed on tech info

 

[gtir bean]

its an r33 gtr one.im changing one of the reducers for a better one in a couple of days so hopefully that will cure it.

 

[ram5ay]

Your cooler could just be working well (gtr coolers are pretty efficient)!
When the air is cooled better it contracts more so you get a pressure drop, so when you up the boost back to 1 bar you get a denser charge at the same pressure, so more air into the engine .
You could also get a bit of a pressure drop caused by restrictions in your pipe run, sharp corners etc. I found when I fitted a frontmount I got a small pressure drop and a bit of lag as the boost came in later because of the longer pipe run, but the motor pulled alot better on boost.

 

[gtir bean]

there never was any leak,it was my little bleed valve thing.i think the spring in it got stuck or something.i set it at 1.1 bar now and it does feel better than before.it pulls like a mo-fo in 3rd compared to what it used to and there aint much lag still.