hey there i just intalled my boost gauge today and the highest reading i am getting is 6psi in all gears, no higher at all
now i have 95 psi compression on both rotors, have a fcd, and a full 2.5 inch exhaust and downpipe with no cats on the car
but i am told that with a full exhaust i should be seeing about 8-9 psi... what could be wrong ? any ideas?
thanks

 

try adding a boost controller of sorts...

 

Your dynomax exhaust is probably a restriction.. I have a full 3" exhaust, but only run 9PSI. But that's at 7K ft above sea level.. Try getting a cone filter and making a custom TID..

 

S4? Your wastegate only is set for 5.5psi, you need a boost controller.

 

yeah..must be the restrictive exhaust..with my 3 inch turbo back i was constantly seeing 9-10psi...woulda seen higher if i didnt let off the throttle.....any idea whats the OD on the pipe before the Y?....

 

even with the stock WG i was seeing 9-10 with the boost creep....also...what rpm does the boost kick in?....i noticed a faster boost kickin also...so that might help u in determining the cause of ur problem

 

well the only thing that is dynomax on the car is the muffler, the rest is all custom piping
what do u mean by what is the "OD" on the pipe before the Y?
i should be seeing higher psi u are all saying.. i wonder why so low.

 

it suppose it could be possible that the wastegate could have been ported... not likely but possible, the shop may have done it when they did the install? or when they took off the turbo before.. im not sure but could that affect it

 

That is a possibility, but i doubt it myself.. I'm not a big fan of Dynomax products myself, and the boost will rise after the packing in the muffler is destroyed.

 

iv had the muffler on the car for about 2 years so the packing should be long gone...

 

I would say it's the 2.5" exhaust. As you see, most get the higher numbers with the 3" exhaust. (s5) I run the 2.5" with DP and Bonez hi flow cat and factory mufflers and only saw @ 7lbs before the ecu upgrade which jumped it to 10/11 psi.

 

I run an S4 TII motor and ported wastegate with HKS downpipe, no cats and an apexi dual N1 and i still creep to 13 lbs hehe The HKS downpipe is a 2.5 inch piece and the dual N1 starts @ 2.5 then flares out.

 

Just a question-How can you get that kind of PSI from a stock engine by just removing cats. I find that incredible. With the RB 3" exhaust you'll only see 10/11. What's you secret?
Thanks

 

maybe really cold nights?

 

with RB turbo back exhaust, ported wastegate and cone filter I see about 6-7 psi and it will creep higher on cold nights.

 

I see about the same w/ my RB 3". Creep to 9 or 10.

 

I really doubt its the 2.5" exhaust. Mine is 2.5" all the way back and I hit 7 lbs by the top of 1st. The boost creeps like hell in all other gears...I need to port my wastegate. Also, how does an ECU upgrade increase your boost?

-Joe

 

i'm running 3" TID and for a while i ran with 2.5" open downpipe. It was loud as allz hell but all I could manage was 400mmHG on my stock gauge and .51 bar on my aftermarket gauge. I'm running no FCD, so my assumption is that my WG has been ported before i got the car. Maybe yours is ported also.

 

i cant really think of any other explanation... my exhaust is as free flowing as u can get without having to muffler.... so it should be non restrictive
maybe ill install a MBC and just turn it up to 8 or 9
solve the problem... hopefully
today im installing a TID and my walbro and hopefully the MBC ill let u know what i see
thanks for all your replies guys

 

I had the same exact problem...

So I took my wastegate line off AND the DP. I ran with an open DP and it still didn't make more then 6psi. Turned out it was a bum turbo. Replaced the turbo and voila - instant 10psi

David

 

dam... if its the turbo thats gonna SUCK cause i cant afford a new one
well i just installed a walbro 255 and in 3rd gear i saw about 7 or 8psi... so its a bit better.. maybe with a TID and boost controller i will see more?