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-   -   Boost falling off (https://rotarycarclub.com/showthread.php?t=15480)

vrracing 05-08-2012 11:28 AM

Yup. Car runs fine as 12psi of boost. The helper spring was the key piece. Havent messed with it since.

Last week the top plastic radiator endcap cracked and was leaking so he installed a Godspeed aluminum rad with a GM shrouded electric fan. Really opened up the engine bay and the polished rad looks really good. It was in the 90s and muggy as Houston here and it cooled very nicely using a Flex-A-Lite thermoswitch to control the fan.

At the same time the kid put a Corksport turbo intake duct as a purely prophylactic measure. Nice piece.

88turboii 05-08-2012 04:56 PM

i have an extra spring on my S5 hybrid too. another problem ive discovered, if you are running the factory turbine wheel, it can cause so much back pressure that it will open the wastegate by itself. the extra spring helps keep it closed until the actuator wants it open. that could have been happening, especially at high rpm. and ive never heard of running too rich that it limits boost, unless its actually misfiring

vrracing 05-08-2012 05:25 PM

Yeah, Bryan @ BNR said the adjustable w/g rod didnt really do much.

Sharingan 19 05-08-2012 08:48 PM

Quote:

Originally Posted by vrracing (Post 193180)
Yeah, Bryan @ BNR said the adjustable w/g rod didnt really do much.

In your particular case, or as a general rule? Seems kinda of silly to offer an "upgrade" that doesn't work... :dunno:

10thanniv 05-08-2012 09:45 PM

I had same issue, lacking boost (6psi) with BNR stage3. I have the adjustable wastegate, which I had to pay for and was set to 12 psi from BNR. I looked for boost leaks for a couple of weeks and couldn't find any. I adjusted the wastegate rod and the boost went up to 7 psi. I finally installed my MBC and got it up to 11psi. Running good now, but wasted money on the adjustable wastegate.

vrracing 05-09-2012 10:58 AM

Quote:

Originally Posted by Sharingan 19 (Post 193236)
In your particular case, or as a general rule? Seems kinda of silly to offer an "upgrade" that doesn't work... :dunno:

Bryan forgot to do the adjustable rod on mine (it is supposed to be part of a Stage1 so I didnt pay extra for it) and I asked him how he made the mod. He told me "I cut the rod, weld a coupling nut on it. Then thread the rod end and adjust it that way. Only around a 2-3 additional psi is all you can get out of it"

So he may be doing it as a bonus so someone can get a couple extra psi over stock. I think it might be better to fit an adjustable helper spring mechanism that would better match to typical goals instead.

Quote:

Originally Posted by 10thanniv (Post 193253)
I finally installed my MBC and got it up to 11psi. Running good now, but wasted money on the adjustable wastegate.

Our HKS EBC and the unaided WG actuator couldn't keep the WG closed so we had to add the helper spring.

Sharingan 19 05-10-2012 02:11 PM

Interesting...

I too have an HKS ECV (EVC 1 actually) and it seemed to have no problem keeping the wg closed to the tune of 15+ psi, however I very rarely (if ever) took the car to redline, so perhaps thats why I never noticed a problem?

vrracing 05-11-2012 10:44 AM

Before the helper spring we would peak at 9.9 @ 4600 and then drop to 7 by 6000 as can be seen in my first post with the graph.

I assume BNR doesnt replace the WG so boost is controlled by a 20 year old spring that has gone thru many heat cycles. It seems reasonable to assume that different springs will degrade at different rates.

I doubt that the version of EVC matters. This one is a Black Edition but I've never been able to figure out which normal edition that maps to. It only displays in kpa but since we use the Zeitronix for monitoring boost it doesnt matter.


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