I've bought a '94 Ra a few months back as a bit of a project car.
Fitted a knocklink and boost gauge right away to see if it was running properly. Boosting to 11.5 psi which is correct for this model, and very little movement on the knocklink.

Now I've got a ScoobyEcu ready to be fitted, but wanted to swap the standard slanty intercooler to a better STi 4 one as a safety measure. This was an awkward job but got it finished last week using new samco hoses and it's original BOV.

Gave the car it's first run in a couple of weeks this morning, and I noticed it was pulling better in 3rd and 4th. Then it started to hit the fuel cut off, as it was boosting to about 14psi.

Is this normal after just an intercooler swap, turbo spooling up quicker?
Or have I done something wrong with the swap?
The car has a full H&S decat.

I know the ScoobyEcu will lift the fuel cut, but don't want to fit it until I've got some answers.

Thanks

 

The intercooler will help with charge temps, add to this the lower temperatures that we have been having recently and that can lead to an overboost situation. I would fit the scooby ecu and see how it is then. You may need a dawes type device to turn down the boost a bit

 

Thanks M8,

I knew I'd see some improvements, but wasn't expecting to see a 3psi increase in boost. It was very cold yesterday morning - about 4deg.

I do have a dawes device and could use that to hold the boost level, I'll see how it drives after fitting the Scooby ECU next week.

DCR

 

There will be less pressure drop accros the bigger intercooler. This can lead to extra boost of about 1-2psi (which is what I saw when a friend swapped a slanty for a My99 TMIC) which may cause you to breach the fuel cut limit.