Aftermarket BOV, performance or wank factor

[Steve]

psybic, some more food for thought:

"You have to remember there were the best minds in the world work on these systems in F1 for over 10 years and in that time no one ever though to fit the BOV for all of its performance and reliability benefits."

here is another one from Garrett

"Garrett do not necessarily have a stand on BOVs, personally I have not seen an issue with a turbo due to not having a blow off valve but they seem to be a good device"

Pretty vague, no evidence of failure - and that is from the manufacturer of the turbos - when they have to give warranty, wouldnt they add ANY clause they could to give them an excuse not to have to pay a claim? make it conditional that if a turbo fails without bov fitted that its not their responsibility - big company, specialise in turbos and spend many millions on developement. Just doesnt add up.

I had a friend who fitted a turbosmart bov, it started lifting under boost, had to be shimmed up, still kept lifting, he just counldnt stop it from lifting under boost. This causes turbo overspeeding, how long does for example the R33 stock turbo last when you start overpeeding it? It would hardly add to its reliability.

So who is it that is pushing the great virtues of a BOV? The manufacturers of the bovs think they are important, yet where is their conclusive testing or evidence - they dont have any.

To me, it seems like the arguement for bovs is greatly comprised of urban legend or myth, perpetuated by the manufacturers of bovs and the likes of hot 4s magazine - with very little supporting evidence.

[Steve]

oh, just had to add this one:

For those that think long term reliability is a non issue in a race car (as they replace turbos all the time) show me any car that does more work than a LeMans 24hr racer and I will show you a chimp that Michael Jackson has not slept with.

[Cefiro_PWA]

oh, just had to add this one:

Bahahaha!!!

now THAT is GOLD! :xmas:

[Roy]

With regards to the LeMans 24 hr cars though. Thats a good point, but what boost level does the GT Class (name the year...they change so often) have to run, remembering that they have to run with a restrictor in place.

Does this change things???...i dont know, hang on i posted a bunch of crap about GT cars a few years ago...off i go to see if i can find it:)

[inissane]

umm Garret would sell/rebuild more turbos if their reliability was slightly compromised by people not running BOVs at all........lol

its seriously not their problem and they know it

in terms of le mans, reliability is compromised in racing for speed untill it influences a cars ability to finish as quickly as it can

[Steve]

yes, they do, its called a warranty

Lemans, a compromise of reliability? a 24 hour race designed to push cars to their limits of reliability isnt about reliability? Where is the reliability being compromised? Its only compromised when they dont finish.

[inissane]

oh sorry, pls continue on your wordy path to BOV enlightenment Steve :confused:

no offence intended dude but im out

[Sydneykid]

yes, they do, its called a warranty  

Lemans, a compromise of reliability?  a 24 hour race designed to push cars to their limits of reliability isnt about reliability?  Where is the reliability being compromised? Its only compromised when they dont finish.

I have been hanging off posting on the relevancy of a purpose built race engine, purpose built exhaust, inlet, restrictor limited, boost constrained, 900 kg car that has a 6 speed pneumatic gearbox. The chassis itself was designed to fit around the engine, so there were no installation compromises either. For heavens sake, they change the turbo specifications and gearbox ratios depending on whether they are running at LeMans or Daytona.

If I had their budget I could probably afford to have everything exactly matched and wouldn't need a BOV either. But I don't, I have a production based engine with an off the shelf manifold that has to fit inside a production engine bay, with production gear ratios and it has to be driven to work everyday and live on the circuit occasionally. Not one ciruit, but 5 different circuits.

It makes about as much sense as the 1980's F1 comparison, which is not farkin much. I was there in Adelaide and saw Senna drive the Lotus, it had heaps of lag and piss poor throttle response compared to the the N/A cars that were all over it in the corners. I will always remember Colin Chapman's philosophy, "an F1 car is over engineered if it lasts the slow down lap after the end of the race". The concept was EVERYTHING on the car should fail the instant it cross the finish line. Otherwise it was too heavy and excessively engineered. :chairshot

I have seen an ex F1 turbo, a friend of mine owns one, the thing is huge, weighs about 30 kgs and has all sorts of exotic materials used in its construction, all the 'ums, titanium, magnesium, berilium etc. I am not suprised it didn't need a BOV to make it through 2 hours of racing, the thing would survive an atomic bomb.

Time marches on, F1 cars have power steering, imagine what CC would have said to an engineer who suggested putting power steering on a Lotus F1 car in the 80's. :werd:

I have had enough of the purpose built race car stuff:cheers:

[Steve]

oh sorry, pls continue on your wordy path to BOV enlightenment Steve :confused:  

no offence intended dude but im out

your weak

[Steve]

For those that think long term reliability is a non issue in a race car (as they replace turbos all the time) show me any car that does more work than a LeMans 24hr racer and I will show you a chimp that Michael Jackson has not slept with.

Why would they use a 30 kg turbo, if one half the wieght with a bov would do the job?

I dont see how its relevant to what works best.

[runn3r]

Try speeding your car which has a 800 HP like the drag racers that stress their turbo(which is much bigger) and see what happens to it. I've seen one that got his turbine turbo cracked.

Racers get to service almost every race. Whether or not it improves the performance that im not sure. But they definitely get to change their turbo from time to time.

I realize one thing that wasnt mention in this thread. Do you possibly think a turbo wouldnt wear off? Why wasnt temperature involved in this issue?

Here's a classic test for the doubtful. Grab an electric fan (the turbine) block the outlet and see what happens.....you'll hear the fan actually speed up, NOT slow down.

I think this is ridiculous.

Why not try using a blower and let high temp intake blow it in while you cover it.

From what i know, most "street" racers gets a Bov and their comments was that it improved their performance.

If you didnt mod your car too high, then the standard bov is just good enough but i certainly disagree that Bov is a wank if you are planning to push your car to the limits in an economical way.

[Roy]

Off topic but this is a funny discussion:)

A Le Mans / Daytona car would not be running the maximum allowable boost pressure for the whole race.

My guess is this would be for fuel economy as well as reliability. Many of the cars still have turbo failures in the race, thing is they are a 2-5 mintue fix on these purpose built race cars...where competitors are bouncing off one another, running out of fuel, breaking gearboxes, getting flats around the back of the track etc.

Sure they dont design them to fail, but with the manner in which they are mounted a turbo failure would be seen as almost an acceptable failure, probably more so then a flat tyre.

So if the category rules allow them to run 2.0 bar, then its possible they could be running as little as 14-16psi for much of the race, only using more boost when strategy dictates. The GT1 cars would have only been allowed tp run a max of 1.0bar certain years

To simply say hey, GT cars etc at Le Mans is perhaps forgetting the bigger picture, that is if they dont run BOVs. And from memory of footage i have of a Le Mans winning GT1, it doesnt sound as though it runs BOVs, but cant be sure. I know the EB110S did:)

Other thing is many of the Le Mans cars ran plain bearing turbos with no water cooling, hello IHI and KKK turbos. They did the job, but yeh there are just so many variables when trying to compare race cars to road cars.

http://www.skylinesaustralia.com/forums/sh...ead.php?t=31650

From the above thread you can see that depending on class they competed in some Le Mans cars didnt run all that much boost

LOL...this aint a BOV thread anymore:)

[Roy]

And sorry one more thing, these cars running expensive specialty turbos with thicker shafts, titanium wheels, sometimes anti-lag etc. They are typically twin configurations running on modest capacity engines with close ratio boxes so always have the right gear etc etc.

So not saying anyones wrong or right, just sasying these things all play a part and perhaps take away from the Le Mans /F1 cars dont use BOVs, as perhaps there is more to it:confused:..........

Its like saying that an ex Indycar Holset/Allied Signal turbo is the same as on a generic truck/road cars.

[Steve]

I think this is ridiculous.

Why not try using a blower and let high temp intake blow it in while you cover it.

From what i know, most "street" racers gets a Bov and their comments was that it improved their performance.

If you didnt mod your car too high, then the standard bov is just good enough but i certainly disagree that Bov is a wank if you are planning to push your car to the limits in an economical way.

rediculous? it proves a point, but maybe you cant see that, fair enough.

So you base your performance beliefes on 'street racers', nice, enjoy your bov, and your neons.

So how many performance build ups have you done? hmm, fark all I guess. And you will probably never have one if you base your theories on 'street racers' nice move.

Roy, its interesting, some do use bovs, some dont - perhaps sponsorship has something to do with it? Proven perfromance, NO, there is no proof - but many examples where turbos, and performance dont seem to suffer witout one. Many examples of manufacturers that remove bovs on their performance, dedicated track cars.

[Steve]

Holset/Allied Signal, aka Garrett, did you see the garrett comment on bovs posted earlier? obviously (understandably) they are at the cutting edge of turbo technology.

interesting, seen photos of indi cars, using what 'looks' like standard tial wastegates - they do have pop off valves, to limit boost, but not bovs.

I just cant get passed the fact that cutting edge, such as indi cars, where technology is tested and refined, yet no bov, and they (garrett) cant say there is a need for one - vs ( as runn3r points out ) 'street racers' and bov companies who swear they are essential for optimum performance and reliability.

Where, for gods sake is the evidence?

[Cefiro_PWA]

rediculous? it proves a point, but maybe you cant see that, fair enough.

So you base your performance beliefes on 'street racers', nice, enjoy your bov, and your neons.

So how many performance build ups have you done?  hmm, fark all I guess.  And you will probably never have one if you base your theories on 'street racers' nice move.

Roy, its interesting, some do use bovs, some dont - perhaps sponsorship has something to do with it?  Proven perfromance, NO, there is no proof - but many examples where turbos, and performance dont seem to suffer witout one.  Many examples of manufacturers that remove bovs on their performance, dedicated track cars.

I run a cheap ass BOV on my SIL80 , but ill be removing it soon..

Ill test it how it differs from running one, and i even use a std AFM ...

Should go the same, if not better :elaugh:

[runn3r]

LOL, Why do F1's need BOV? Man they arent even allowed for turbo.

[Cefiro_PWA]

Check out this porsche Lemans engine..

Where is the BOV?

Oh shit , i forgot.. they dont use one. :whip:

[runn3r]

Where, for gods sake is the evidence?

Mod your car up, tune it till its gets 800hp. Don need any fancy stuff, just ya standard bov. Try boosting your turbo to the limits for a couple of weeks.

We will be happy to hear the test and ill be happy to hear it from you.

Or maybe if you arent about to ruin your turbo yet, try an after market bov and see the performance.

Take a video and you will be the first tester and we all would be very thankful.

-end-

Information about F1 Engines go to

http://f1technical.net/article4.html

[Cefiro_PWA]

Where, for gods sake is the evidence?

Mod your car up,  tune it till its gets 800hp. Don need any fancy stuff, just ya standard bov. Try boosting your turbo to the limits for a couple of weeks.  

We will be happy to hear the test and ill be happy to hear it from you.

Or maybe if you arent about to ruin your turbo yet, try an after market bov and see the performance.  

Take a video and you will be the first tester and we all would be very thankful.

-end-

Information about F1 Engines go to

http://f1technical.net/article4.html

Too bad its already been done by RICE RACING, but not with 800bhp unfortunetly..

This time Twin GT3540R's where used on a Highly ported and tuned 13B engine.

Making over 1000BHP with minimal lag for a big circuit.

NO BOV's where used.. heh.. who give's a crap.. if you spent your money on a BOV or what not, thats your fault.