Hello guys,

I have a few questions i would like to ask the turbo crowd. Do you guys use boost controlers , boost timers ??? I know some are designed to plug into a harness to show all of it's possible functions ( blitz and greddy come to mind ) and im wondering if anyone has anything like this on a 3rd gen... or is it mostly a stock turbo car thing??? I know BOV are needed, but are the boost controlers and such needed or possible for one of us to use?

What BOV do you guys perfer also?

Thanks alot guys,
Opha

( soon to become a more intelligant on the art of turbos )

 

I stuck 2X 1st gen DSM (eclipse) Bov's onto my twin turbo's intake. They are cheap on ebay ($30-$40) and they are effective to 18PSI when crushed.

 

You can, it’s not really necessary.

BOV’s are needed? Why?

“A more intelligent” (sic) what?

You may want to start using a spell/grammar check or something before making statements like that.

 

Good thing the original poster stated he/she wanted to become more 'intelligant' in the art of turbos and not the art of being 100% grammatically correct. English is not the native language of everyone in the US, let's show a bit of leniency before we start with the internet e-thug grammar police attitudes, especially since the original poster seemed quite nice and cordial in his/her request for information.

 

First, I dealt with his question (well, basically didn’t really see why he was stating what he was) before the “internet e-thug grammar police attitude” which was mostly joking (as in “that’s a funny thing to say considering your typos while saying it”) and no worse then the first line in your post.

As far as the native English speaker bit, I am not and I still learned to properly express myself so others can understand me. My parents and grandparents were naturalized citizens and they did also.

 

ehh, give me a break it was early in the morning when i wrote that. and i type and forget to proof read alot .

I was generally asking what accessories do the turbo users have on their cars, or have expeirence in dealing with. I can see the add effect and use of some of the boost controllers. From what i understand they allow you to change boost levels, monitor boost fluctuations and some of them have the ability to tune a boost curve or have a different boost setting for each gear. Im sure much of this would be over kill, but im sure it would be nice to change the boost setting from a lower to higher psi with out getting under the hood really.

Correct me if im wrong but BoV or a Recruitlating BoV should be used in turbo set ups to protect the turbo from compressor surge while shifting or revving up to show off the BoV it self. It's a safety feature non the less, but i would think it's important to protect your turbo.

Just curious as how much boost you guys are running also?

Thanks again,
Opha

 

ive noted today that even when the turbo is NOT building boost, when you let off the gas the blow-offs still open to release the built up pressure in the intake pipes. crossfire knows alot about that sort of thing, he will tell you so long as you speel chek ure stuf.

I plan on running about 12PSI maybe more if it handles it decent enough.

 

Turbos are spinning even at idle, and moving a decent amount of air (just remove the TB connection, and put your hand in the way), so the BOV will at least give the air a path to go. It's not an option - you need one. At least a small one. Too small, and you pop off intake plumbing, but cross that bridge when you get to it. I still don't have an electronic boost controller, and am just relying on the wastegates for boost control. The electronic controller gives you better wastegate control, but isn't necessary. The 5 psi springs are in there now as I dial in the fuel/timing maps, and then I'll add the electronic boost controller to control the wastegates. Boost level will be set just under the point of where I run out of fuel, first with these 30 lb SVO's & Walbro pump, then with the 72 lb low imp injectors sitting here, and then the limit of the pump. Eventually, I plan on baffling the tank, and fabbing a bracket to run double intank pumps. Max boost would depend on your engine internals (compression, strength of parts, tolerances) and your airflow parts (heads/cam/intake/exhaust). Max boost on this engine should be around 15 psi on pump gas, and who knows with leaded race gas.

 

Huh, if you need one then why don’t many OEM setups have them? How many even built up GNs/TTAs run them at all? My 2.3 turbo ford (Cougar XR7, 5 speed) didn’t have one, I never broke anything, had problems with it spooling on the shifts, never blew off any hoses and didn’t see any evidence of compressor surge (“clean” compressor wheel tips…).

Has anyone ever seen any documented proof of damage/wear from not having one? You know that the GM setups had to at least pass their 100K mile durability tests… similar deal with the fords…

They do sound cool, they also cover up when you throw a bad, high speed shift, they also add complexity and one more point for things to leak/break.

Belt driven blowers, are a different story, they need a blowoff or bypass or you _will_ break things (or at least have the hoses shoot off after every high speed run)

My current setup is being built without one, and probably won’t have one unless I stumble on one for cheap/free.

 

wow, i didnt realize that alot of the factory set ups did not include one. Thank you for bringing that to my attention . Now with out the boost being released while you shift, will that cause the turbo to " stumble " ? or take a little longer to spool up at all? Or will the pressurized air stay in the intake trake and force itself into the engine when the Primaries and secondaires open up again?

Thanks alot for the info...

and i cant find a spell check, so sorry.

Opha

 

In a higher performance level than most factory turbo setups we are usually trying to create a more efficient power source. As far as we have found, when you don't have a BOV is that yes, you create compressor surge, and create (as noted above) a lag on the spool for the next time you wanna get on the throttle. hence why most race setups have a BOV, the faster you can get the air out and less stress on the shaft the better (dirty or clean side). As far as damage... I've heard of bent shafts, but on set-ups that were of 25+ psi.

 

You lift your foot when you shift? I think we just found your problem…

 

You control boost (during WOT) with a wastegate. The wastegase senses boost with a vacuum/boost hose. The wastegate will release some of the exhaust pressure when you reach enough boost to overcome the spring force keeping the valve closed.

With a stronger spring more boost is needed to open the valve.

An electronic boost controller uses a valve on the vacuum/boost hose to feed less boost to the wastegaste. By doing that the wastegate will stay closed at higher boost.

You can also use a 'needle valve' and a restrictor on the vacuum/boost hose to raise boost in a similar way as the electronig boost controller.

If you have a strong enough spring in the wastegate you don't need any other boost controller to get the boost you want.

One benefit with a good electronic boost controller is that you can have different boost at lower gears to keep the traction.

When you release the throttle it is good to have a BOV. The more boost you have the more important it is. A piston type is better than a membrane type. If you have a MAP sensor you can vent the boost to open air. In that case it is best to have a dual piston BOV to make sure that the engine does not use unfilterd air.

If you have MAF you should recirculate the air from before the trottle to after the MAF.

A turbo timer will feed oil to the turbo for a while after you shut the engine off. It is not needed if you let the turbo cool with the engine on idle for a while before shutting it off.

 

This is a dual piston BOV.
http://jobyteknik.homeip.net/fredrik...1/MOV02977.MPG

 

If you plan on racing with a manual trans car, and having the transmission last (i.e. - not doing WOT power shifts), I would recommend even getting the plastic $30 Bosch from the Volvos (or other euro cars). For a drag only car w/ an automatic - who cares... I've had my intake pipes blow off the TB, which could be fixed by bolting them together. If the turbos are spinning at 100k, and all of a sudden get stalled, that creates tremendous loads on the bearings. On ball bearing turbos, I'm sure it doesn't matter as much, but for the bushing bearings that rely on a thin layer of oil, if that gets squeezed out often enough, the bushing & shaft would wear prematurely. To each his own, I guess...

 

I run an innovative multi stage boost controller operating an innovative pro-gate wastegate. I like the controller because it is closed loop, with it's own map sensor monitoring boost and making sure you have only the amount of boost you dial in - no more or less.

As for blow off valves I think they are pretty much a waste of time and money, unless you like the way it sounds(which I dont). I also think turbo timers are a waste of money and are for lazy people who dont want to sit in their car and lket it idle down for a few minutes before shutting it off.

HTH,
Steve

 

On a manual car you gain performance with a BOV because you can keep the turbo spooling during shifts.

With an automatic transmission you don't gain any performance.

Aside from performance the BOV still does good. It minimizes the stress on the turbo bearings and you are less likley to blow hoses apart.


Some people say that a BOV is not needed because they ran for years without one and they did not have any turbo bearings that failed.

That is like saying that it is better to use cheap oil because I did and the engine did not blow up.

If you don't like the sound then you can make them quiet too. It is not a reson for not using them.

 

huh, transmissions, clutches, rear gears, axles… aren’t wear items? Aren’t you supposed to replace them at least as often as you replace brakes? Don’t tell my wife about these strange ideas, or I’ll have to start explaining the 2 broken rears in the basement, the half dozen sets of gears missing assorted teeth… and the couple of clutches (can you throw 40# of clutch/flywheel in the trash and have the garbage dudes take it?)

I’m pretty sure that the Volvos used a metal can assembly… the one you’re thinking of is from the saabs (used to come with the vortec blower kits). If you’re going to spend the duckets on one get the Porsche/Audi part number instead… costs about the same but has a stiffer spring and is better built. FWIW, my brother blew 2 of those apart before we gave up on them and welded up a butterfly linked right off the throttle linkage for a bypass, of course, he’s using an eaton blower).

That’s the argument for it, but I don’t know that I’m buying it since I’ve never had a turbo that didn’t outlast the engine that it was bolted to, and rebuilds are cheap (bearings for my Holset are $11 from the Cummins Power Systems dealer, just walk in and walk out with the parts). Doesn’t get much easier then that, not much else that I can fix/rebuild on the car for cheaper, faster or get easier, and these things were designed to go 200-500K miles without a rebuild.

 

I run an automatic, and have run various blow off valves from time to time(HKS, Greddy, Turbonetics, ect...)but prefer to keep the block off plate on there. I've never blown the hoses apart even with boost up as high as 29psi, and with regards to turbo longivity I've seen way too many turbo buicks last for 100K miles and more without problems. Not that I'm saying mine will last that long, but I figure I'm gonna upgrade way before the turbo ever lets go.

It's not so much that I dont like the sound of a BOV but rather I like the sound of not having one. It's just my opinion, lots of people run them but I feel there are better places to spend time and money. I've owned and raced 8 turbo cars so far and currently own 4, none of which had BOV's and none of which ever had a problem with turbo failure.

If you are going to run one I'd suggest the dual port aftermarket ones rather than some of the stock units mentioned in this thread, especially if you plan on running any real boost. The dual port ones seem to seal better under boost and open faster(and stay open longer)when you come off the throttle.

HTH,
Steve

 

No i dont lift off when i shift. I was kind of thinking if the boost would just force it self into the carb, but of course it would... it's compressed air. And after seeing so many people not use BoV's really has suprised me. Too me i think the whole thing about BoV's is the sound they create, i like the sound so i will use one once i get my turbo system set up ( maybe in a few months or so )

Now what are the best books on forced induction and turbos that you guys recomend me reading?

One more thing, i know of one intercooler set up using 2 small cores. Has anyone used this besides the person who designed it, or do you guys have any intercooler set ups?

Thanks very much guys, sorry for being a newb

Opha

( looking for a spell check program to make the big dog happy haha )

 

For the most part, I don’t care one way or the other… form follows function, and function is often the simplest reliable setup that gets it done. I’ve run high teens boost in my little ford turbo without one and never saw a problem…

McInnes. There’s other more technical books but get a handle on this one and you’ll be able to discuss this topic with most people and not sound like a moron.

Lots of people have done that. The biggest reason to do it is packaging.

my $.02… just don’t make comments that would attract attention to typos. FWIW, I type enough all day that I rarely bother proofreading anything, don’t have time, so I type most forum responses in word, let it do it’s autocorrect thing, drag it into the response box and don’t worry about the rest.

 

I checked out turbomustangs.com and they have a cool video section. One thing that i noticed is that alot of the set ups are very very loud. Im wondering if it's turbo compressor wheel design or just the size of the turbo that make the difference in sound from a mostly stock and quiet set up to a high boost and loud loud whine sound? I personally would rather to keep the whine down to a minimum on the lower end just so i can cruise the town with out making a show of itself. I probably wont be going with alot of boost, but just curious if some turbos are just louder then other turbos?

generally what would a stock 350 be able to handle in boost? and if the same engine was built up with forged internals and had a intercooler?

Sorry for all the questions, im ordering the book you recomended.

Thanks guys,
Opha

 

https://www.thirdgen.org/techbb2/sho...hreadid=217973

This is a 1987 IROC 350 and the engine is stock exept for larger injectors.

We are now using 10psi boost. With the Holset HX50 it starts to build boost at 2000 RPM and we have 10 psi at 2500 RPM and up.

We will probably find out how much it can take.
As long as it get's enough fuel don't knock it can probably take a lot. We have a 2-bar map sensor and will probably get there. ( 15 psi boost )

I think foged crank is needed for higher RPM, not for boost.

 

That's kind of a loaded question. It's not really a matter of how much boost it will take, it's how much boost will it take for how long?

My old worn out stock shortblock with cast crank/pistons survived running 16psi and spinning ~7000 rpm. . .for a while. I believe it lasted about 20 1/4 mile passes to be exact, a number of which were in the high 9's. Of course, soon thereafter, it spun two rod bearings, bent the crank .020" and bent all the wristpins.

 

Books:

In addition to McInnes 'Turbochargers' book, I would also recommend Maximum Boost by Corky Bell. I know there are some guys who have some issues with the fact that he tries to promote his Aerochargers in that book, but the book is more current than McInnes' and has a lot of good info and excellent pictures. I believe McInnes' book is from the early eighties, and as you all know turbo systems have come a long way since then.

 

My recently finished dual exhaust on my twin turbo camaro is (DEATHLY) quiet. its quieter than my 305 with just a cat-back, except for under boost of course. its quieter than my friends Sr20DET (turbo 4 cylinder) and he has a cat-back too, (but its no 350 under the hood...)

Im thinking the mustang guys just all tend to run 40 series flowmasters because everyone and their sister likes the "cool sound". They just want the attention.....

 

awesome info guys, thanks sooo much. I never figured a stock block and bottom end could take some much . haha, this is going to be a fun project.

Time for sleep now,
thanks again.
Opha

 

What was it a stock short block out of? What the hell are you doing over here anyway, are you following me around?

Most people that have a problem with Mr. Bell’s book have a problem with made up facts and a lot of opinion stated as being fact to make it a good advertisement, not just the fact that it is an advertisement for his products.

A lot of the mustang guys run open exhausts or just a bullet or something simlar to get the exhaust volume back up. You know the difference between a car having a cat in the exhaust and not? You get about that difference to 2x that difference with installing a turbo.

 

I really don't know to tell you the truth. All I can tell you is it was a cast piston, stock rods w/stock bolts, cast crank, 2-bolt main monster. I did run a Summit cam with refaced stock lifters in it, so maybe it wasn't [i]bone stock[/]. It was in the car when I bought it 12 years ago.

That's right. I had a couple more points to discuss regarding the kolkhoz system, as well as 19th century naval warfare.