Is there a different dv that can accomadate for this flaw after the ecu being chipped (as not to worry about surges and having to change the spring)? I came across another good brand recommended on here named Bailey.

 

stratmosphere, evo, bailey's, forge, etc... are all piston based designs and practically the same thing

there's a diapraghm dv from APR called the R1 which doesn't use springs.

read through this thread- https://www.audiforums.com/m_671411/tm.htm

 

Ok, so I think I have the set up correct. It is just as you explained.

1) Go with the forge 007 (my choice) using the green spring

2) After it is chipped, get a n75h valve (I will purchase this anyways as I am reading many posts with people having surging problems after chip and would rather avoid the problem before it arises)

3) Boost gauge to moniter my boost (not needed but recommended)

Now the only thing that remains is I have no idea what a n75h valveis. What is that? And can you link a page if you know one that sells them at reasonable price you would use yourself? Thanks.

 

Pardon for wasting your time with the last inquiry. I should have searched harder. I found one on ecstuning.com. But now for a different question(like I said, I have no idea about mechanics and would not want to purchase wrong item). Is the n75h the same thing as the n75?

http://www.ecstuning.com/stage/edpd/...;productID=122

 

It is, just that one will increase boost by 2-3psi. Little costly for such a small increase, no adjustments,and risk of not working with your chip. If you want to mess with boost levels, a stock n75 w/ a mbc or mbc alone will be better. But thats just me

 

if i remember correctly, there are a couple different kinds, there's a j, h, c, and i think even a n. The h valve is supposed to hold the most boost. i got mine from audizine's classifieds section, so i dunno about the ECS one, but it says "race n75 valve" and the only one i've heard of referred to as the race valve is the H, so im pretty sure its the n75h, but i would contact ECS just to make sure

here's a chart on a completely stock a4. H is the h valve, C is the c valve, and X is no n75, and the numbers are what the boost reading was at that RPM in 1st and 2nd gear.

rpm.....C.....H.....X
3000....6.....8......4
3500....6.....7......4
4000....6.....7......4
4500....5.....6......4
5000....5.....5......3
5500....4.....5......3

and under WOT the h valve gives 9psi, c valve gives 7psi, and bypassing the stock n75 gives 4psi


this is on a pre 01 a4 so the boost is slightly less than what you would be seeing

 

yeah you could do that too, but my n75h cost me 35 bucks so it was a cheaper option than a mbc. if you want to get a mbc


or you can just bypass the n75 and do this

 

The wastegate is set to 5psi. Shows atleast 1psi drop @ 5psi on the stock ic setup [:'(] With i chip, its more like 2 or 3 according to boostfactory.