[chiefsotos]

When i installed the forge dvs valve, although they made the clack sound for locking, the front one played a little up and down (about 2-3mm). Forge ensured me that this is normal so i made some datalogs.
The first one is with stock Dv and the second with Forge Dv.

I think there is similar boost behavior so everythink is ok, right?

But i have a question:

When i am cruising and suddenly press the gas pedal deep i saw in the boost gauge some oscillation which take place only for half second or so.
(Example 1: in idle the boost gauge saw vacuum -19, when i step the gas it immediately rises at 0 psi but stays there for some fraction of a second and then continues up
Example2: When i am cruising at 3 psi and put the gas pedal deep the boost rise at 10 psi but oscillate a bit there and then continuing up)

Is it possible that this oscillation occured to the yellow springs i use in forge dv?
Or it is just my idea and that boost oscillation was there with the stock bv also?

[jcarlucci1]

Looks like stock holds boost better than the Forge valves

[bulldog_yyc]

are these connected to the stock charge pipe? if so then the play you described is probably causing a poor seal. Pick up the Riss or Stett charge pipe instead and you will get a better seal.

[john boxter]

Originally Posted by jcarlucci1

Looks like stock holds boost better than the Forge valves

wow that sucks if its true

[luca335i]

I have the same problem. Gonna put the stock ones on soon.

[Panoz]

Hmm...if the second graph is the graph using Forge DVs , then you have an issue of poor installation.

Turkish 335: Can the forge DVs get fitted to the Stett & RR chargepipe? Have you did it yourself?

[Alpina_B3_Lux]

Originally Posted by Panoz

Turkish 335: Can the forge DVs get fitted to the Stett & RR chargepipe? Have you did it yourself?

STETT delivers adapters for the OEM replacement Forge DVs, in order for them to fit on their charge pipe. I'll get these within short - just drop STETT a line and they'll provide you with these.

Alpina_B3_Lux

[enrita]

Your DVs might be leaking at the connection itself to the OEM charge pipe. this is known to happen if the installation is not done properly. mine have never leaked and i have had them on more than 6 months with the yellow spring. I did as well a smoke test to be sure. My boost is very steady.
I am getting my STETT pipe next week for Meth installation and i got the adapters from the forge dvs.

[chiefsotos]

Guys why do you think the stock dv hold boost better than forge?
If you look the Iat in the first graph is near 70c and in second with forge is only 55c. I think that is the reason the the boost in forge's graphs is a liitle lower.
I upload a third graph with forge dv and wot in 4th gear. It seems really stable to me.

P.s.: I think that scoops really work with dual cones intake. The iats lowered about 15-20 degrees only with the scoops in the same ambient temperature 11c. (The first graph is without scoops)

[Panoz]

Originally Posted by chiefsotos

Guys why do you think the stock dv hold boost better than forge?
If you look the Iat in the first graph is near 70c and in second with forge is only 55c. I think that is the reason the the boost in forge's graphs is a liitle lower.
I upload a third graph with forge dv and wot in 4th gear. It seems really stable to me.

P.s.: I think that scoops really work with dual cones intake. The iats lowered about 15-20 degrees only with the scoops in the same ambient temperature 11c. (The first graph is without scoops)

Commented 5 differrent things in just one post...

The boost graph looks stable but the boost level is pretty low (under what settings is this log taken ?). If you had lowered the torque settings in purpose its seems that the boost is stable.

In higher boost (your graphs above) it seems that you either have boost leak or the Forge DVs are unable to hold boost (unlikely to be this case).
I proposed you NOT to change spings...and you did. So make sure the DVs are sealed well and has not gone loose due to the hoses bending into the engine bay.

By the way ,your IATs are extremely high for the given period...with your FMIC i never see more than 42 to 45degrees. Anyway the reason of the boost drop is definately NOT the IATs i was running 55-60degrees too with stock intercooler but never seen boost drop to 11-10 psi at these temps. It must be a leak

[chiefsotos]

Originally Posted by Panoz

The boost graph looks stable but the boost level is pretty low (under what settings is this log taken ?). If you had lowered the torque settings in purpose its seems that the boost is stable.
By the way ,your IATs are extremely high for the given period...with your FMIC i never see more than 42 to 45degrees. Anyway the reason of the boost drop is definately NOT the IATs i was running 55-60degrees too with stock intercooler but never seen boost drop to 11-10 psi at these temps. It must be a leak

I run stage1 with catless dps and i don't have lower the user torque settings. If you see the 3d graph the boost is about 13,5 psi all the time. Mine FMIC is the stock one and the only think that i added from the first graph is forge dv and scoops. So i supposed that the temperatures been lower just by the scoops.
What i don't know is if the boost drop (from 14,5 to 13,5) is occured to the lower iat (about 15-20c degrees)?

Any way to test the dv for leak?
If they leak then shouldn't i hear a whistle sound all the time while accelarating? Or the procede, in order to achieve the target boost spool the turbos harder and show that boost in datalog?

[cn555ic]

Originally Posted by chiefsotos

I run stage1 with catless dps and i don't have lower the user torque settings. If you see the 3d graph the boost is about 13,5 psi all the time. Mine FMIC is the stock one and the only think that i added from the first graph is forge dv and scoops. So i supposed that the temperatures been lower just by the scoops.
What i don't know is if the boost drop (from 14,5 to 13,5) is occured to the lower iat (about 15-20c degrees)?

Any way to test the dv for leak?
If they leak then shouldn't i hear a whistle sound all the time while accelarating? Or the procede, in order to achieve the target boost spool the turbos harder and show that boost in datalog?

It could also leak at the couplings of the FMIC beside the forge...

[Panoz]

Question: as the springs into DV gets stiffer the less responsive the throttle becomes?
In principle this should be happening...is that a fact though?

[bulldog_yyc]

Originally Posted by Panoz

Hmm...if the second graph is the graph using Forge DVs , then you have an issue of poor installation.

Turkish 335: Can the forge DVs get fitted to the Stett & RR chargepipe? Have you did it yourself?

yes both charge pipes allow for installation of the forge DV's. I have fitted them to the RR charge pipe on my car.

[chiefsotos]

Originally Posted by Panoz

Question: as the springs into DV gets stiffer the less responsive the throttle becomes?
In principle this should be happening...is that a fact though?

When you mean less responsive you mean more turbo lag?
My story: After i made the first datalogs with yellow springs (you know the results allready turbo lag of about 1-2 second when step on the gas) i put on the green springs. I didn't manage to made some datalogs because in the first 2-3 wots the car went to limp mode with code 30ff(just exactly when the boost exceeds the 13psi).
Furthermore when i stepped on the gas from any rev there was a lot of turbo lag.The car behaved like an old school turbo car (The first 2-3 seconds like an atmospheric car and after that a big kick)
2 hours ago i put back the stock dv and the problems solved No more turbo lag and very quick response.
The New forge Dv definetly leaks in the stock charge pipe and i am very disappointed with them! (I installed them 4 times all with the manual directions)
Tomorrow i will see the logs with stock dv to see if everything is still ok...

[bulldog_yyc]

Originally Posted by chiefsotos

When you mean less responsive you mean more turbo lag?
My story: After i made the first datalogs with yellow springs (you know the results allready turbo lag of about 1-2 second when step on the gas) i put on the green springs. I didn't manage to made some datalogs because in the first 2-3 wots the car went to limp mode with code 30ff(just exactly when the boost exceeds the 13psi).
Furthermore when i stepped on the gas from any rev there was a lot of turbo lag.The car behaved like an old school turbo car (The first 2-3 seconds like an atmospheric car and after that a big kick)
2 hours ago i put back the stock dv and the problems solved No more turbo lag and very quick response.
The New forge Dv definetly leaks in the stock charge pipe and i am very disappointed with them! (I installed them 4 times all with the manual directions)
Tomorrow i will see the logs with stock dv to see if everything is still ok...

get the Stett charge pipe and then put the forge DV's on!!

[luca335i]

I'm oscillating like crazy at around 3-4000 rpm. In DS
I can't feel it though cuz it shoots through the gears faster I guess. I can hear the motor accelerate and deccelerate as the boost moves up and down. Pisses me off.

[chiefsotos]

Here are the two more datalogs with stock Dv inserted again. The first one is 2-3-4th gear and second 4-5th wot. I noticed that the boost after 5500 starts falling in the first graph. The funny think is that the stock valves sealed very well in the stock charge pipe(don't play even a bit) and i don't think that they leak. The boost response came back to normal again (no turbo lag).

Now the weird think:
In the boost gauge i was seeing boost around 14,5-15 psi until the shift points although the procede after 5500 reads a falling boost!

How is this possible?
Is it a boost leak the the boost gauge can't read it while procede, which reads boost from the other side of manifold, cathes that leak?

Another strange think:
In the first of the next graphs when i wot 3d gear the boost is very stable, after the first gear change the boost starts falling from 5500rpm and up.
In the second of the next graphs when i wot on 4th gear the boost is stable, after the gear change the boost starts falling from 5500rpm and up.
Now, if you see in the above graph of 4th gear wot the boost remains stable in all the rpm range?
In all these situations the boost in boost gauge remain stable and more than 13psi.
If there was a leak shouldn't be there all the time in all gears?
Is it possible to be a procede reader error?