Exhaust under boost

[Hevis]

Ok, its turning out that it is impossible to get the needed document for the emission test free Garrett T25 4g63 n/a conversion. Visited TÜV Nordic today with the papers I got from this forum earlier but they were useless since they weren't official enough. Thanks for the help tho. The guy at TÜV promised to search if the part number is correct, its the last hope we have here . ..no wait there is one more....it is also possible to buy a 4g63 and put it under the hood with no tests...

So I was wondering if I after all pay the damn emission test. But how possible it is that I dont pass them? Im about to change the injectors with bigger ones maybe stock 450cc and go with the T25, stock exhaust manifold , downpipe, gs-t MAF and a 95 eprom gs-t ecu. Shouldn't it burn cleaner/quite similar compared with the earlier since the reaction has more oxygen and pressure...

 

[tenn-gsx]

Is your test a dyno test or just an idle and free rev test? If its not a dyno test then It should be pretty similar I would think as long as everything is operating correctly.

 

[Hevis]

the car will be wired all over and sensored for exhaust particles, co2 etc while reving on a up to 60mp/h

 

[tenn-gsx]

I guess it would all depend on the load. Under boost the car must be much richer than a n/a car would.

 

[Hevis]

But does this automatically mean higher emission and particles since the burning temperature and pressure is boosted. the ecu adds more fuel but the higher amount of oxygen burns it away

 

[tenn-gsx]

The air to fuel ratio is different under boost. Which means there are less parts o2 per 1 part of fuel at any given time under boost. How much this will affect your specific situation im not sure. But in order to get a reasonable idea then just look at U.S model 1g turbo VS. non turbo models emissions from the factory. This will give you a relative comparison since in both 1g models the engine was still a 4g63.

 

[knochgoon24]

If the guys in California can pass emissions with a modded car, I bet you can too. Do a search and read up on some of their tips.