Cup mod boost query

[wolvo]

Hey guys just checked my carb jets and i've got 135 main and 100 ac which im advised is a good start for the 16 psi boost im running (with alloy intercooler), my query is now i have the cup mod done the turbo spools up very quick and when it starts boosting it shoots upto nearly 20 before settling down to 16. I have used an in car boost to set it upto 16, what i want to know is will this momentay "spike" cause any damage or is this normal ?.
Was thinking maybee i should fit the spider i have to limit it to 16 psi dead or even remove the in car boost and fit bleed valve, or adjust actuator to 16 (if theres enough thread). But maybee this is the norm and im worrying about nothing......can anyone please advise ?

[HULK]

No it's not normal and shouldn't do that. Keep ya incar controller but plumb it up to ya spider under the bonnet to set ya maximum boost at 16psi. Either that or put in a restrictor in the pipe from ya incar to the carb.

You connected the pipe to the carb top or carb base/passenger side of the carb??

[SCHWARTZ]

get a few pix up of the pipe runs or explain how you have done it maby its something to with the way its plumbed up.

[Markey Mark (BD)]

I'd remove the in car controller and just set the actuator to 16psi, for the spiking sounds like there's too much preload on the actuator and its become weak so the wastegate is being pushed open.

Having these spikes can be a poss prob as it can result it lean spots in the rev range which can cause future damage.

[wolvo]

Straight from actuator into T piece one end of T piece to controller and other end straight to carb basehttp://i756.photobucket.com/albums/xx205/mwolvo/Current%20Ride%20R5%20GT%20T/actpiping.jpg

[HULK]

Do you have a spider valve handy? If so I will put up a photo in the next hour of how to plumb it all up.

[wolvo]

yes mate brank new spidey valve sitting on shelf ere

[HULK]

heres how it all goes together

http://i224.photobucket.com/albums/dd152/007impreza/incarboostcontroller.jpg

Below is how to do it with a spidervalve, note how the other 2 ports are left open to air, also put the pipe to the carb top not to the carb base like you have at the moment and block the unused carb nipples off


http://www.rtoc.org/boards/attachment.php?attachmentid=6302&d=1273945206

[wolvo]

thx for input guys, have removed the dodgy T piece which came with in car boost controller and have run the controller from spider which has stopped the spikes .I set spider at half a turn and its 17 psi (made me smile) but i've turned it down to 16 on controller as i dont wanna pop anything and its fueled for 16.
How much boost pressure you guys running on standard turbo's ?, or better still how much were you running before standard turbo went pop !

[Markey Mark (BD)]

16psi is limit for the T2 to run efficently

[wolvo]

Hey all , is there any difference between running 16psi at the carb body like the cup mod suggests or running 16 psi from the lobster side of things ?

[IANMM]

there is a 4 psi difference between the two

[wolvo]

cool so i understand the pressure difference, but is there a running difference between having it set to 16 psi whether its connected to the carb or the lobster (understanding adjustments will be different according to which point i connect too)

[IANMM]

well if you got 16 psi at carb top you will have 12ish going through the carb bottom so a true representation is through the carb base

[Jimmy_GTT]

I have a similar problem what I have posted in the 'MAP courve' thread.
I also have a boost spike but around 5500rpm. I'm running on the cup mod, but I have a Hallmans boost controller installed which is not bleeding the actuator. It has a ball against a spring. ( http://www.hallmanboostcontroller.com/index.html )
It is connected in the line from carb base to actuator.
I also have this spike if the boost controller is not installed.
Shall I try to connect it between carb top and actuator?
THX

[THE MASTER]

keep it simple . put aLL THE CONTROLERS IN THE BIN set every thing up to hold the boost :burnrubber:

[Jimmy_GTT]

keep it simple . put aLL THE CONTROLERS IN THE BIN set every thing up to hold the boost :burnrubber:

As I have already written I also have this boost spike if there is no boost controller in the system.
http://www.renaultclub.hu/courve.JPG
The courve of the MAP changes paralelly to this if I increase/decrease the boost.