I just got tuned on speed density with my 6262 turbo but ordered the wrong coupler bend for my setup so I had to use my 3inch pipe with filter till the end of the week..My question is changing the 3 inch pipe to 4 inch pipe with a bigger filter will it change my tune..afr etc..and will it pick up some any hp for changing the piped with the bigger filter??

 

What turbo are you using? You want the smoothest transaction possible. If your turbo has a 2.5 inlet, then going from a 4" to a 2.5" will cause turbulance by that coupler.

I use a 3" pipe to my stock turbo. What a recently found, the biggest difference that will make is the filter.

 

I agree. You really don't need a massive 4" intake for a smaller 64mm inlet. If you have a larger 84mm or higher inlet then that is when you start to get into the realm of needing a 4" intake.

 

b.b 6262 turbo with 4 inch ported shrud cover

 

?? anyone??

 

MAF or SD?

 

s.d

 

Yes 100% the tune will change.. You need a 4" intake for that turbo setup to breathe properly anyway.. You will pickup hp going from 3" to 4" with the large filter..

 

You shouldn't need a retune.

EDIT: LOL well I suppose AWD knows better and is faster on the response!

 

I agree. With a turbo and that large of an intake you will be bottle-necking the airflow coming into the induction inlet on the turbo. Swapping to a 4" intake will increase that a good bit and could lean you out, best bet is to get a retune or at least log your AFRs and adjust the fuel tables accordingly (if you are a knowledgeable tuner).

 

Talked to a very good tuner today and said that the tune will hardly change maybe the afr's might change about 1 point if that..The 6262 trubo had a 4 inch cover but if you look in the middle of the cover and wheel it's self it's only 3 inch's in size..

 

Well actually if you want to be accurate the inside of the 4" cover is ~62mm and 3" is 75mm.. And whichever tuner you spoke with who told you it will be off by 1 point i am going to assume you mean by .1 which is ridiculous for someone to think changing to a larger 4" filter and pipe can only change AFR by .1. I know for a fact its going to change the tune by much more than .1 as we have done this probably 20x and logged the difference..

How about adding a velocity stack to a turbo and picking up 20hp?? Do you think the car wont be leaner by .1 and pick up 20hp.. Thats adding a velocity stack to a car that already has a 4" pipe.. Imagine now 3" pipe going to 4" then adding a 7" filter or velocity stack..

 

Anyone agree with this??

 

The guys at AWD probably have more time and experience testing different setups with SD conversions then any of the internet jockeys that are self proclaimed experts. I would trust what they are saying almost as confidently as if I had done the testing myself and saw the same results. Feel free to PM me if you have any other questions or concerns.

Josh

 

We remembered just last week we did a filter swap only on an FP Black car that the customer had some small filter on.. I swapped it for a larger 7" big KN and derek had to add fuel to the car.. Swapping to 4" pipe + filter needs adjustment.. Will your car blow up?? probably not.. If it was tuned in right before the pipe and filter that is.. But will it need retune to be right and make the safest power, yes it will..

Thanks josh for props..

Mike