Low boost issue solved on a tune sled

[kennyspec]

What is the purpose of the blow off valve being run through a solenoid? I have my blowoff valve solenoid bypassed and the blow off hooked direct to a vacuum source. Now I can actually hear the blow off valve. Almost seems like when it was connected to the solenoid it wasn’t working at all.

 

[Firedawg1998]

I never hear my bov either, If I dropped the throttle quickly I hear some turbo flutter. From what I could come up with, the abv sensor monitors pressure at the bov and intake manifold and is supposed to reduce any turbo lag by watching things more closely and I read abv sensor works in conjunction with the watse gate operations. Also supposed to reduce backfires.. hard to find sidewinder info on stuff one rarely has to deal with but on automotive applications, this is some of the stuff i read.. maybe its worth 2 cents? Lol

 

[kennyspec]

All I heard before bypassing it was surge as well . There is no way it can reduce lag. If the wastegate is closed and the bov is closed there is no way it can help reduce lag. I also think bypassing the bov solenoid fixed my random sd26 codes.

 

[snowbeast]

This is my sled , 19srx that this happened to. I only ran it last year after purchasing for 140km in stock form. I thought it was a rocketing. I did get an sd26 code both days out but found some loose clamps on my turbo to change tube. Felt that was my issue.. spent the summer tearing it apart and doing multiple cat fixes and felt she was tune ready. Yamamarc help me stay on the straight and narrow path to success and installed the pm multi tune. With this tune I was finally able to see boost pressures.. As the smaller lakes froze over myself and 2 cat turbos began to play. As much as it seems to go and ran without hesitating or codes, my sled would hold its own but never in first, only showing 11.9psi and 8500rpm. The boost leak hunt was on after adjisting secondary wraps and clutching up and down trying to find a sweet spot. First large leak was found at the midpipe right at the turbo clamp. Next outing showed 12.2 and 8500rpm.. leak tested system upto 23psi and everything seemed tight. Then I notice my air filter. It is a td cai kit with an oiled k&n with pre-filter. Well it was all twisted and showed signs if heavy collapsing. The photo i have of it is too large but it looked like I crushed it as hard as I can with my hands, bending all the pleats. I really thought this was my issue but next outing it ran 13.2psi and 8600rpm.. slowly and painfully getting there but fresh out of ideas. Last advice I received before loading it up was to check ever tiny hose around the sensors for blockages or damage and then to start swapping sensors at the lake with friends.. so I started at the p sensor, no hose on it, all good visibly. Next is map sensor, hose dips down and goes to abv... all hoses in good shape and no blockages.. now the abv and wastegate sensors are tucked underneath abit but labelled very well if u know what your looking at. Upon first inspection the wires didn't look right.. appeared stretched to their location, actually crossing each other.. my first thought was poor design but wasn't shocked. Started to trace hoses and I started to questions things. Yes its ridiculous that those 2 plugs are identical but they are labeled well so there is still no excuse.. shocking that the sled ran so well like this. I burnt a tank of 93 and the only issues were low boost and the odd knock light that happened twice.

Now the rewarding part. swapped the plugs and headed to the lake. 8700rpm and 17.3 psi on 270. 8900rpm and I've seen 18.9psi on 300.. no knock lights
Truly sounds better and hauls the mail now.
There was a few minds at work here diagnosing my issues and I thank-you all
U know.who you are, lol !!!

Now that is great news,so now do you peddle by those sleds you may have had a problem with before?

 

[Firedawg1998]

So hard to tell when your trying to find 300hp of traction on regular lake conditions but I def hold my own and have them worried.. I have 5000 miles on my studs. I bought the sled used with a not so great pattern and only leave 4 really good scratch lines so i will always be struggling with that. 5000 miles on studs as well compared to the other 2 boosted cats I run with who have new longer studs, patterned inside and out where mine are all up the center.. Had a good test the other day, with my 22t gear against one of em with a newly studded stock geared cat, I get a 3 sled jump on a rolling start..we stay like that until over 100 and then I start to creep away. The other cat has gears and 144 new, long studs inside and out. . I can't take him but doesn't leave me either. They both have o2 sensors and at -15c, on 270hp, I had the most fuel left over after a 100 mile ride.. they don't think they have any boost leaks and I know i dont have any so maybe thats the difference. Either way, I've been bragging about that around the lunch table, hehe
We really need more snow around these parts to do some more hard pack testing. On a side note, as much as I love the doo 850's, all they could say at the end of the day, was "man are those sleds fast", hahaha. Biggest compliment i could expect...