Intercooled 2L-T/3L question

[malteser]

Just finished charge cooling my turboed 3L, and now have a little bit of lag (before it was non-existent). I understand this is normal and can live with it, my question is from where should the fuel pump boost compensator signal feed from ? At the moment its feeding from the intake manifold (post intercooler) so I'm assuming the lag is retarding the fuel compensation. Would it be better if I t-eed into the compressor/wastegate line ?

Also, I can now see a boost spike of 0.6/0.7 bar before it settles to 0.5bar (reading from same pressure line as boost compensator - post intercooler). I'm assuming this is normal since the volume of air to be pressurised has increased significantly now, is it ?

Thanks!

 

[GTSSportCoupe]

Just finished charge cooling my turboed 3L, and now have a little bit of lag (before it was non-existent). I understand this is normal and can live with it, my question is from where should the fuel pump boost compensator signal feed from ? At the moment its feeding from the intake manifold (post intercooler) so I'm assuming the lag is retarding the fuel compensation. Would it be better if I t-eed into the compressor/wastegate line ?

Also, I can now see a boost spike of 0.6/0.7 bar before it settles to 0.5bar (reading from same pressure line as boost compensator - post intercooler). I'm assuming this is normal since the volume of air to be pressurised has increased significantly now, is it ?

Thanks!

I think the intake manifold is the best place to get the boost comp pressure from. You should not have to live with the lag. There is actually more oxygen (denser cooler air) in your intake manifold now than before. It might just be a matter of adjusting your boost compensator it's self now that you have an intercooler. Probably need to add a little more fuel low down? Maybe try turning the cam on top of the boost comp to increase your initial fueling? Or turn the pin to a more aggressive fuel curve (assuming it's eccentric). It's a bit of an art to tune these. Worth reading up on before you do it.

Not sure about the boost spike. Is it a factory turbo and waste gate? Do you have a manual boost controller? Maybe there is something wrong with it?

 

[malteser]

Yes that is also what i thought about adjusting the boost compensator to have more fuel down low. I'll try that first then. Half a turn to start with ?

Yep all factory turbo and waste gate and no mbc yet. Where do you read your boost pressure from ? This morning someone told me the spike is due to reading pressure post intercooler.

 

[GTSSportCoupe]

Yes that is also what i thought about adjusting the boost compensator to have more fuel down low. I'll try that first then. Half a turn to start with ?

Yep all factory turbo and waste gate and no mbc yet. Where do you read your boost pressure from ? This morning someone told me the spike is due to reading pressure post intercooler.

I have a stock turbo also and basically the same intercooler as you, and I don't see any boost spike. Only difference is I run a boost controller. I read the boost post intercooler also.

Read up on boost compensator adjustments before doing it. Mine is electronic, so I can't give you direct experience from the 2LT/3LT. However I have helped a friend tune his 1HDT boost comp.

Biggest thing is just make small changes at a time.

There is a cam on top which can be turned to change the start of the fueling (start position on the fuel pin).

The pin can be turned to change the fueling curve (more or less aggressive fueling). I'm pretty sure the factory pin is eccentric....

A star wheel can be turned to increase or decrease the spring tension. This spring resists movement of the pin/diaphram. Usually the spring tension is increased to counter an increase in boost. Or it can be loosened off to get into the higher fueling faster.

Best if you read up on it as much as possible. The boost comp has a huge impact on the way your motor runs, and is well worth learning how to adjust.