[Slickrat]

Heres my Mods and My video...

2009 335i
Dinan S2 Flash
Rpi exhaust cat back
Catless DP's
Stett Charge pipe HKS bov
Injen Intake
Riss Racing Catch Can
Clutch Delay valve
Kw V2 suspension
BBS LM 19''
TWM STS

Heres my concern...The graph is showing compressor surge between 4-6k RPM...When we looked at the surge more closely we were seeing losses between 20-25 hp mid range..It was jumping back and fourth between 365-345 hp. If you pause the vid you can see it...Now..my reasoning for this is that the RPM is calling for boost and the turbos are not big enough for the demand..is this correct..also when I get on the car from around 4k it seems to not surge at all and pull harder..Is this a Tuning issue? or is it because we started at 3k Rpm in 4th gear on the dyno? And help/info would be great..I was going to contact DINAN and see if they can look at my dyno info and modify the Map or something... Overall good numbers 360whp 400tq

[Never-Enough]

How much boost?

[boom]

That's most likely the dyno. It looks like an inertial dyno (dynojet) and those sometimes don't load properly. A lot if the early giac dynos looked like that.

It could also be because the dinan tune is not set up properly for the catless downpipes.

[Doug007]

That is NOT compressor surge. People have gone up to over 20 psig on these turbos (on race gas and methanol) without serious issues. Even then, the holdup to more boost was the limitations of the fuel system and the limit of the stock manifold air pressure sensor (~22 psig)

Compressor surge is when the compressor reaches it's pressure ratio limit and high pressure air begins surging back to the inlet. From experience on this platform, this limit is beyond 20 psig. Dinan S2 is not anywhere near there.

This looks like a dyno issue to me. How does it feel on the street? Losing 25whp will be noticeable on the street.

[Slickrat]

Originally Posted by Doug007

That is NOT compressor surge. People have gone up to over 20 psig on these turbos (on race gas and methanol) without serious issues. Even then, the holdup to more boost was the limitations of the fuel system and the limit of the stock manifold air pressure sensor (~22 psig)

Compressor surge is when the compressor reaches it's pressure ratio limit and high pressure air begins surging back to the inlet. From experience on this platform, this limit is beyond 20 psig. Dinan S2 is not anywhere near there.

This looks like a dyno issue to me. How does it feel on the street? Losing 25whp will be noticeable on the street.

even on the street you feel it and hear it almost resonating going wom wom wom wom when punching it from a lower rpm, but accelerating well...there def is a issue with something

[Slickrat]

Originally Posted by boom

That's most likely the dyno. It looks like an inertial dyno (dynojet) and those sometimes don't load properly. A lot if the early giac dynos looked like that.

It could also be because the dinan tune is not set up properly for the catless downpipes.

Can DINAN reflash the computer to resolve this?

[Slickrat]

Originally Posted by Never-Enough

How much boost?

15-16 lbs of boost

[Jeff@TopGearSolutions]

It's either hardware related like boost leak or HPFP, spark plugs, Coilpacks ETC

Or its in the tune. Unfortunately with Dinan you cant log to see what is actually going on.

[Slickrat]

Originally Posted by Jeff@topgearsolutions

It's either hardware related like boost leak or HPFP, spark plugs, Coilpacks ETC

Or its in the tune. Unfortunately with Dinan you cant log to see what is actually going on.

I had the hpfp replaced about 5 months ago.....i guess i can do a boost leak check.....in going to say the catch can may be the issue if its a boost leak...any advice on the bov? I was told to get rid of the HKS...I had a tial but it was sooo quiet...any suggestions?

[vasillalov]

Originally Posted by Jeff@topgearsolutions

It's either hardware related like boost leak or HPFP, spark plugs, Coilpacks ETC

Or its in the tune. Unfortunately with Dinan you cant log to see what is actually going on.

Ummm, of course you can! Any CAN bus based logging device will be able to log what's happening with the engine.

The Bavarian Technic tool is one example where you can log the engine. Also, you can see what's happening live with the Rixter boost gauge.

So yeah, there are a few options out there for logging.

[Jeff@TopGearSolutions]

Originally Posted by Slickrat

I had the hpfp replaced about 5 months ago.....i guess i can do a boost leak check.....in going to say the catch can may be the issue if its a boost leak...any advice on the bov? I was told to get rid of the HKS...I had a tial but it was sooo quiet...any suggestions?

I thought about mentioning the RR OCC but I have one and my car runs seamlessly so there are mixed reviews to say the least.

I run a Tial but HKS isnt a bad BOV.

Originally Posted by vasillalov

Ummm, of course you can! Any CAN bus based logging device will be able to log what's happening with the engine.

The Bavarian Technic tool is one example where you can log the engine. Also, you can see what's happening live with the Rixter boost gauge.

So yeah, there are a few options out there for logging.

Sure he can but not through Dinan logging capabilities (which are non existent was my point), so yes he would have to purchase something like a Bav Tool.

[boom]

If it's on the street, then it's the tune not being set up for the downpipes. The turbos are spooling faster than expected and the corresponding overshoot and the subsequent opening of the wastegates/throttle closure is causing this. I'll bet if you swapped your stock dps in the oscillation would go away. Get a cobb or a giac.

[Turkeybaster115]

Originally Posted by Slickrat

I had the hpfp replaced about 5 months ago.....i guess i can do a boost leak check.....in going to say the catch can may be the issue if its a boost leak...any advice on the bov? I was told to get rid of the HKS...I had a tial but it was sooo quiet...any suggestions?

That could be your problem. The latest software they install after replacing the fuel pump: ista 2.0? has not been very compatible with Dinan. People have had a lot of problems combining the two, including severe engine damage: http://www.e90post.com/forums/showth...ighlight=Dinan
Just food or thought.

[Slickrat]

hmmm....well with the mods i have warranty is not an option correct?

[Turkeybaster115]

Originally Posted by Slickrat

hmmm....well with the mods i have warranty is not an option correct?

Dinan I assume, picked up your warranty. If there is engine damage they should cover it. Let them know right away about this issue.

[boom]

Originally Posted by Slickrat

hmmm....well with the mods i have warranty is not an option correct?

You have a bunch of stuff that isn't Dinan and that they would use to void your warranty.

[JAXT88]

I have Dinan S2 as well and I think I know exactly the" bog vroom bog vroom" feeling you are describing, it happens quickly only when you punch it in low RPMs. It only happens to me once in a while, I just got the warranty work done and they put the dinan flash on right afterwards so I am not sure if there is a difference driving stock.

Let me know what you find, I was curious as well but it happens so infrequently and I am not sure its weather related. Our mods are quite similar too (I have DVs though).

I would note that this usually occurs when I am in 2nd gear and punch it around 2K RPMs.

[Litos]

here's a stupid question: did you let your car warm up to 180 degrees ???

what you are describing sounds similar to when you try to WOT the car when it hasn't reached 180 degrees.

food for thought.....

[Slickrat]

Originally Posted by Litos

here's a stupid question: did you let your car warm up to 180 degrees ???

what you are describing sounds similar to when you try to WOT the car when it hasn't reached 180 degrees.

food for thought.....

car was warm....did 3 pulls...it was 104 degrees in the shop that day

[cgeorge]

max boost on stage 2 is not 15-16. it's more like 13.2 I think.

[boom]

Originally Posted by cgeorge

max boost on stage 2 is not 15-16. it's more like 13.2 I think.

Exactly. The target is 13.8 but the car is spiking because the dps are letting spool much faster then closing throttle, opening wastegates. Wash, rinse, repeat.

[nitehawk]

OP, please see if you can log some data...
I have Dinan stage 2 as well and am about to install the AR catless DPs. So, I'm really curious to know the root cause of this.