Need Advice on Supercharging

[rocket 5979]

Hold on everyone! It seems I may have stirred the pot a lttle bit here. That was not my intention.

First and foremost I want to eliminate any reference to turbo's. Take that out of the equation. My application is a centifugal supercharger.

The MAF is attached to my air filter. So the air is drawn thru the meter well before it reaches the supercharger. So a recirculating sytem is required since the air charge has already been metered. Correct? And for 6 to 8 or so lbs of boost, a simple non-adjustable bypass valve should be sufficient. Yes they are cheap, made of plastic, not the most effiecient, and so on.

I originally brought up the blow off/pop off/bypass, whatever you want to call it valve, because I have not seen it addressed on this forum. And if running the limited boost I stated above wouldnt be beneficial then I wouldnt even of brought it up.

I know everthing you read is going to have errors and inconsistencies. The quotes I post I cant guarantee their accuracy, but before I post I research and then pick what I think seems the most logical to me in laymens terms since I'm no expert.

Not doing this to get peoples blood boiling. Just asking questions about certain things I dont fully understand. And if I say or qoute something that is way off base, please call me on it.

Thanks to eveyone for your help and support. Just remember the title of the thread (Advice on supercharging) bcause I get confused easily when things start drifting off topic.

There is no problem at all. I know that you are trying to learn. That is why I am ensuring that all information that you gather, whether it be from in this forum or from outside, is correct. Sometimes what starts out as a simple misunderstanding can grow into a person having to buy parts they didn't originally plan for. Just trying to ensure that doesn't happen to you is all. Good luck with the build.

 

[rocket 5979]

I have a tial 50 MM BOV and it does flutter when the pressure is low (2-3LBS). If the boost is on up there, it will vent great; when the boost is low and I get off the throttle, I get a flutter sound.

tffff tfffff tffff tffff tfffffffffffffffffffffffffffffffffffff (Kind of like that)

Are you sure you aren't hearing your wastegate and resulting compressor surge? If the BOV is adjusted correctly there should be more or less zero fluttering sound coming from either the BOV or the WG. I know when I adjusted my BOV a little too tight that I went back to having compressor/wastegate surge. Loosened the screw just a little on the BOV and got it back where I wanted it.

 

[zachow3]

I have a tial 50 MM BOV and it does flutter when the pressure is low (2-3LBS). If the boost is on up there, it will vent great; when the boost is low and I get off the throttle, I get a flutter sound.

tffff tfffff tffff tffff tfffffffffffffffffffffffffffffffffffff (Kind of like that)

Great to hear you got your truck up and running. Now you can just enjoy all the hard work you put in. I saw a burn out video you posted but unfortunately I couldnt hear it because I think I have a sound card issue with my computer. Still, very impressive! Even without sound.
How you guys get so much power out of 6 cylinders is really amazing.
I know you were having some issues with the tuning. Is that all straightened out? And, correct me if I'm wrong, you tuned it remotely with James?

I hope when I get to the tuning stage that being on a dyno I can get any bugs worked out in one visit.

I felt since the weather was nice that I needed to attack the front yard today. I let it go to long. My asthma was acting up more than usual so I had to take frequent breaks to catch my breath and that gave me a chance to check the forums thoughout the day.

I saw you post here 2 or 3 times. I appreciate that. Not many people follow these long threads. Which is understandable.

Nothing new to report with the truck. Ordered a few more parts. Including the bypass valve I was interested in. It wont make noise like your BOV since the air will dump back into the inlet port of the S/C. Thats OK, because if this thing is to loud, my wife might refuse to drive or even ride in it. That would spell doom for our camping trips.

 

[justin146]

Found this at Summit Racing. Same price on e-bay. $19

Just go to autozone and buy an IAT sensor for a 99+ Lightning. They will have two listed, get the threaded one. Then you can drill a hole and JBWeld on a threaded insert (look in plumbing section at Home Depot)

 

[Jakee]

I tried tuning the thing myself and actually got pretty far. I started noticing the knock sensor was activating and I figured it was time to let a pro take it from there. That's when James did the remote tune for me. It took about a week or so. What I did was make a run at night, send him the logs. He'd have the next tune ready for me when I got home the next day. I'd make another log for him and so on and so forth.

The process will start with a part throttle log. Once that’s good, you’ll start on full throttle pulls. This is the MAF curve tuning to get the air/fuel just right. Once that’s done, you start adding timing in a little at a time. It’s actually not all that bad. The hardest part is getting everything hooked up for the first time and ready to log.

 

[Jakee]

Are you sure you aren't hearing your wastegate and resulting compressor surge? If the BOV is adjusted correctly there should be more or less zero fluttering sound coming from either the BOV or the WG. I know when I adjusted my BOV a little too tight that I went back to having compressor/wastegate surge. Loosened the screw just a little on the BOV and got it back where I wanted it.

I didn't know you could adjust the tial BOV. I thought the only way was with springs.

 

[rocket 5979]

I didn't know you could adjust the tial BOV. I thought the only way was with springs.

Whether you have an adjustment screw depends on the make/model of BOV you go with. Regardless if you set the preload with a spring and setscrew or just go with higher and lower springrates to achieve what I mentioned before it still turns out to be the same thing in the end. Your Tial BOV just uses different stiffness of springs rated at different vacuum levels based upon what your particular engine pulls at idle. I usually prefer to have a BOV where I can not only swap springs but also adjust a setscrew so I can really finetune my BOV response. After my last turbo system revision I have my BOV set pretty well. No fluttering whatsoever in the system. If I had it set just a little too tight then it would cause compressor surge. If I had it adjusted a little too loose then the BOV would come open under normal vacuum conditions rather then vacuum+boost release conditions. Tweaking it just right allowed the best of both worlds.

 

[Jakee]

Well, the spring in mine is barely enough to hold it close at idle. The fix would be to get a stiffer spring, then worsen the "flutter". In my eyes, it works and that's all that matters to me. The flutter happens at low boost and that’s not enough for me to worry about. The spring in the BOV matches the suggested stiffness for the vacuum I pull at idle.

What type of BOV to you have?

 

[rocket 5979]

Well, the spring in mine is barely enough to hold it close at idle. The fix would be to get a stiffer spring, then worsen the "flutter". In my eyes, it works and that's all that matters to me. The flutter happens at low boost and that’s not enough for me to worry about. The spring in the BOV matches the suggested stiffness for the vacuum I pull at idle.

What type of BOV to you have?

It sounds like you have the correct spring if it barely holds it closed at idle. As long as it holds it closed at idle then that is what is the benchmark you should shoot for.

I have a Greddy S BOV. I think I have it in the sig for the LS.

 

[zachow3]

So I got my Bosch bypass valve and was tinkering with it. Decided to give it a little test to see how it would perform. Hooked it up to an intake manifold vacuum source on the truck, and at idle the bypass valve was wide open, as it should be. Reving the engine closed the valve, again as it should. But at a sustained RPM the valve would open again. My assumption is this valve will bypass at all times unless the engine is under increasing load. I can see the benefit to this in reduced load on the engine during normal driving, and a no boost indication since the air charge would be bypassing all the time. I guess I was wondering if without this valve I would have some boost as RPM increased, again under normal acceleration and not WOT. This seems to be an all or nothing setup. Boost will only build under WOT or increased engine load. There is no adjustment. It's either full open or full closed.
Of course this was done N/A since I'm not running boost yet. Please chime in if my thinking is basakwards.

Here's a pic. Sorry it's not that clear. My camera is old by digital standards and doesnt have much of a macro mode.

 

[Jakee]

That looks sort-of like a hairdryer?

I'm not sure. What RPM is it coming open at?

 

[zachow3]

That looks sort-of like a hairdryer?

I'm not sure. What RPM is it coming open at?

I'll bet that the air that does come out will dry your hair.

Actually, When I hooked it up it was full open at idle. Revving the engine by hand at the T/B the valve closes for an instance, whether I release the throttle or maintain a constant RPM. Then it opens again. I dont know what RPM I'm at because I'm not inside the truck. And it gets pretty loud, not to mention scary when I rev it very high by hand. Like I said it seems to be closed at WOT due to low vacuum, or open during normal acceleration or driving. This sounds normal to me. It bypasses the air until you put your foot into it. So I assume I wouldnt see any boost just driving down the road. But when I floor it, It should close and remain closed while under a load. Thats when boost would build.

 

[reserved50]

thats the same piddly bypass I have I think, the upgraded porsche/audi version whatever, for 6psi under I think those pathetic powerdynes still dont need one especially on an auto trans. I looked at how to hook it up and bought all the fittings and decided against it because it was starting to look like a rats nest under there. Id rather just snap a belt(pretty rare with low psi) and replace it than bother with it, but thats just me. I think i went to home depot and bought some plumbing fittings to tap into the blower lines, looked like a mess when I mocked it up.

 

[zachow3]

thats the same piddly bypass I have I think, the upgraded porsche/audi version whatever, for 6psi under I think those pathetic powerdynes still dont need one especially on an auto trans. I looked at how to hook it up and bought all the fittings and decided against it because it was starting to look like a rats nest under there. Id rather just snap a belt(pretty rare with low psi) and replace it than bother with it, but thats just me. I think i went to home depot and bought some plumbing fittings to tap into the blower lines, looked like a mess when I mocked it up.

It doesnt sound like your overly thrilled with the Powerdyne. After all the expense of building your engine, why would you settle on a budget S/C? For me, in the beginning it was about cost, since my engine is all stock and fairly high mileage. It hasnt turned out that way as I keep dumping money into parts but other then abandoning the whole project, I have to play with the cards Im dealt. The bypass valve seemed like a good idea from a reliability standpoint, but if your running your setup without any issues, then perhaps thats one less thing I need to worry about.

 

[reserved50]

I just wanted a bolt on, I almost went with a vortech sn95 setup and modify that with the use of the stock sn95 brackets with modified A/C lines, crank pulley etc whatever. I actually dont have a problem with the blower so far, been maintenance free for the 10,000 miles its been on there, revved to redline many times with an overdrive pulley. Only thing that worries me is when I upgrade the impeller to hit a whopping 8-9psi, then I might need to upgrade the belt and maybe install the by-pass if the belt happens to snap shortly after. After all boost is boost, especially good since I dont have hot engine oil heating up the internals and needing an intercooler. It'll hit mid 13s and sub 5 sec 0-60 I think it was,and at 4600lbs at the scale, so its not too shabby . I'll probably split the block running over 12psi anyways, its pretty close to 500hp now I'm guessing.

What i have a problem with is that PD kit is worth about 1500-2K for what its worth. out of a 10 I give it a 2, looks home made.

The only time I see you having any real reliability issues without running a bypass is if you like to hit WOT often and "snap" the throttle shut continuosly not allowing the boost to flow thru the TB. So basically driving normally isnt going to give you any problems.

 

[zachow3]

I just wanted a bolt on, I almost went with a vortech sn95 setup and modify that with the use of the stock sn95 brackets with modified A/C lines, crank pulley etc whatever. I actually dont have a problem with the blower so far, been maintenance free for the 10,000 miles its been on there, revved to redline many times with an overdrive pulley. Only thing that worries me is when I upgrade the impeller to hit a whopping 8-9psi, then I might need to upgrade the belt and maybe install the by-pass if the belt happens to snap shortly after. After all boost is boost, especially good since I dont have hot engine oil heating up the internals and needing an intercooler. It'll hit mid 13s and sub 5 sec 0-60 I think it was,and at 4600lbs at the scale, so its not too shabby . I'll probably split the block running over 12psi anyways, its pretty close to 500hp now I'm guessing.

What i have a problem with is that PD kit is worth about 1500-2K for what its worth. out of a 10 I give it a 2, looks home made.

The only time I see you having any real reliability issues without running a bypass is if you like to hit WOT often and "snap" the throttle shut continuosly not allowing the boost to flow thru the TB. So basically driving normally isnt going to give you any problems.

Reserved, I need a favor.

My kit is missing a pulley and I have no idea what size it should be. It's a six rib idler pulley mounted above the water pump that replaces the stock smooth pulley that was there. If you have your installation manual, it is step 15. Or it can be viewed on Powerdynes site. If you could measure yours and let me know what size it is ( just diameter would be fine) I would really appreciate it.
Thanks, Brett

 

[reserved50]

good luck, PD had no consistency, they gave me a smooth pulley . I swapped out all my pulleys anyways and played a game of charades and now I have a various assortment of pulleys all over the engine compartment. If you really want to use the ribbed pulley for that idler best bet is do what I did (I have all smooth pulleys), go to a local parts store armed with a list of pulleys off the dayco site (whatever brand your automotive store carries) and take them home and try each one and return the ones you dont need, you might have to add a washer behind the ribbed pulley since alignment is critical, with the smooth pulleys its of less imortance and Im sure thats why I had one in my kit.

On mine I re-used the stock large flat steel OEM Exploder pulley along with a GM auto spring tensioner and ditched PDs method of manually setting the accessory tension since my belts squeeled every other week or so.

 

[Jakee]

It sounds like you have the correct spring if it barely holds it closed at idle. As long as it holds it closed at idle then that is what is the benchmark you should shoot for.

I have a Greddy S BOV. I think I have it in the sig for the LS.

I hate to keep hi-jacking this thread but I just noticed something.

My BOV is NOT completely closing at idle. I finally sat there and watched it for a couple of minutes while idling and this thread is what prompted me to do it. It appears I need another spring and this maybe why I'm hearing a flutter. Evidently, the spring I thought I had is not the one I have.

Sorry, just had to clear this up.

 

[CDW6212R]

...

On mine I re-used the stock large flat steel OEM Exploder pulley along with a GM auto spring tensioner and ditched PDs method of manually setting the accessory tension since my belts squeeled every other week or so.

Very good tip/mod, belt tension is very important for reliability.

 

[turbo cat]

you woulnt see more power with higher octane gasoline. Octane numbers are the resistance to detonation...as in the higher the number the more resistance to actane. In fact if you can get away with it 87 octane will provide more power and performance than 92 oct (87 fuel is said to burn quicker)

As for ethanol you live in vancouver theres a e85 station in longview I belive you may want to look into what it would take to convert to e85

E85 is currently cheaper and has a octane of 105+. It also has intercooling abilities for if your going boosted. The fuel is cold to the touch and colder fuel being injected helps cool the air charge. You lose gas milage when running e85 but its worth it being a cheap race fuel. It is also more emissions friendly and cleaner burning. parts and internals stay cleaner like fuel pumps, rails, valves...

depending on the setup you can research on w2hat has to be done to convert as you already are working with tuning devices (also may need bigger injectors more e85 is neeeded per burn thatn gasoline. Change of the fuel filter very very frequently when first making the switch ( e85 cleans the fuel tank of any debris and varnish and sends it through