Jump to content
SAU Community

Recommended Posts

A turbo go bang as as Denton R33 put it, after constant abuse by lifting off full throttle at full boost often and overboosting. Both ways will vary between turbos in how long or when it will make the turbo go bang. It want happen because yours makes a flutter sound which normal and will be heard better when you remove the stock airbox and filter set up. Adding a front mount will change the sound in terms of duration, frequeancy and volume, but no the fact it happens or not.

My brother had a stock black top rb20 in his 31 4 door and a APEX GT Spec front mount. It had the most awsome and loud flutter. He ran 14psi with the stock ceramic turbo and never hurt it.

My 32 has a blitz BOV and because of the spring tension being higher than a stock silver top blow off valve, it doesn't open unless there is a substantial pressure increase caused by a sudden lift off under high boost. Which is when you won't it to go PERCHEW not flutter.

If you drive around normally and change gears during the spool up phase and not on boost, it makes a nice tight flutter unlike my brothers one which was loud, long and slow sounding.

A weak setting in any BOV will cause the BOV to open under moderate pressure levels giving you a single PERCHEW not the flutter maybe before you are on boost. No good for spooling up which will make the car feel laggy.

just set up your bov fairly tight so it only opens when your backing off over say 8psi, then you get the flutter when your taking it easy and the benefits of the bov when hard at it.

to change the sound just back of the throttle at different speeds, too easy

  R31Nismoid said:
Keep it the way it is.

They come plumb-back for a reason  :rofl:

Your car will probably stall and play up if you remove the bov.

Well last night I did what sky-rkt said and took off the bov and just placed an alluminium cut out over the hole and then put the bov back over the top and screwed it all back together, and now... It flutters! : ) It hasn't effected the way the car drives at all! Still boosts the same, revs the same! everythings the same - just a nice flutter now - that's all!

Cheers

  R31Nismoid said:
it'll be slower on the gear changes as the pressure aint going out where its meant too = hinderance in performance

Yeh maybe so - but it's not that bad that I can even feel the difference - still pulls the same through the gear changes, maybe cause it's not boosted there isn't that much pressure to get out? I dunno feels the same to me

  moo_r32 said:
do you think it would make a diff if you cover up half or more of the hole? it would couse a bit more back pressure yet still make use of the bov???

I reckon you'll get a bit of both! but I cant imagine the flutter being all that loud?

Only one way to find out I guess..

i have dabbled in this area a little bit... how to get the 'sickest cooler dose'. There is a constant debate as to whether removing all bovs will damage/reduce the life of your turbo... but basically its up to the owner whether they think its wise or not...

Anyway, on all of my cars that were turbo charged, it became obvious to me the piping/cooler size/turbo/air filter would depend on the sound of the 'flutter'.

Decent sized cooler piping, aftermarket fmic and a pod filter will amplify the sound.... but the ONE mod to me that made the sound very loud, was removing the standard plastic piping from the turbo to the airfilter/pod to a steel pipe...

I usually have bovs on my car, but they are tightened up to the sh1thouse. So 10psi and under it will flutter, and then when you release the throttle on full boost, it will flutter and bov simultaneously... sounds great =)

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Any difference in induction noise?
    • If I got a dollar for every flipped commuter missile I've driven past I'd have two dollars   Some people get into wild adventures on the road and I doubt it's gender or ethnicity specific. I'm just glad I don't usually drive during peak times.
    • Just got the car back and gave it a good run back home Power wise, whilst it only made a extra 5 killerwasps up top at 7200 rpm, it made more power everywhere from 2500 rpm and kept pulling much harder all the way, to the point of me relearning when to shift so I don't hit the 7200 limiter, with the old intake it seemed to take alot more time to rev out, and, throttle response is also much improved  As I didn't want to remove the bumper every time I serviced the air filter (basically every aftermarket and fabricated CAI has the filter behind the bumper) it currently has a hektic exposed pod in the engine bay sucking in hot air, this will be rectified shortly after some some of my CAD (cardboard assisted design) for a alloy heat shield feed by the OEM intake tube behind the bumper, this will cop some wrinkle black paint, as well as the intake pipe for that totally OEM look... The only fly in the ointment was that the OEM "strut" brace doesn't fit over the rear runner of the new intake with the 2.5 engine is in the engine bay, as the 2.5 raises the engine up by 20mm, it's not a war stopper, and I didn't notice any difference without it in some twisties, but....... MX5 Mania is bringing in some GWR "fancy pants" braces that apparently do fit, if it bolts up I'll grab it, it is also stiffer than the OEM one, which is a bonus All in all I'm happy with the outcome      Fancy pants "strut" brace that gives the required clearance      This is where the clearance issue was, the GWR extends out past this
    • Well, I'm back from the dyno today. Some things do partially make sense. The pod filter/airbox delete picked up between 6-10rwkw on 98 - because heat soak does kind of affect things and there was playing with tune/timing/AFR. Oddly enough, the car was running much leaner than before. So lean it was audibly pinging on the dyno which I got video of:   70de0dd5-2099-4a71-8b10-6fc833fb9d59.mp4   We're talking going from ~12.7 in the past to the first run being at like ~14.0. It is now tuned to ~12.5 on the Dyno, which correlates to about ~12.1 on my wideband in the car. These matched last time, which is very odd. The dyno plots only show the dyno's reported AFR - should be last time, yet now it no longer agrees and was way leaner. Nobody has an explanation for how a pod can make the car run notably leaner, yet not really give any more power when you add fuel in. A few different types of intake design were tested:   94c22c34-7991-4902-af85-314b5f5bf352.mp4   There was no difference other than IAT with the pod sticking out of the bay. The pod sticking out of the bay (but connected) is actually still warmer than what I usually see on the road. Removing the pod entirely lost about ~2kw. But to be fair, all of the runs could be argued to vary by that amount when temperatures climb etc etc. It's safe to say that the filter isn't causing any restrictions of any note that can be reasonably altered in any way. This is in line with what I'd expect given the Engine Masters testing. 323KW on 98 and ~335KW on E85 is actually a pretty solid result, up about ~45kw from 99% of LS1 cammed combos, with generally much larger cams/exhaust etc as well. It is after all up 42KW (98) and 54KW (E85) from before. +10KW from a pod and removing the box is cheap as chips compared to what the head work cost per kw No, I did not get to drop the exhaust and test. When it comes to exhaust... it all just seems to change frequencies and cost or gain 2hp here or there. I don't realistically think I'll drop this to test it - because there's not much else I can really do about it/route it any other way/make it bigger/just bought mufflers. Engine masters beat the hell out of headers with a hammer to deliberately kink them and didn't lose power at all, I sincerely doubt that going larger primaries would help. If it were even possible for clearance/conversion reasons... which it's not... I may throw the E85 in there at some point and do a drag run to see what MPH it traps for science. It isn't lost on me that ~320kw Skylines do trap about the same MPH that ~370kw F-Body/Corvettes do in the USA for the same  or similar weight. (122-125mph). Of course, if I go there and trap 104mph or something then I'll just 'accidentally' have an accident on the way home from the drag strip and buy a M4.
×
×
  • Create New...