TBDevelopments

see i'm not a huge fan of this either because raising the fuel pressure means the injectors will be flowing slightly more fuel when ever there operating, so even in the midrange map when you don't actually need any more flow, but it will increase fuel flow at topend where its needed when running 1 bar. ideally you want to run some kind of fueling computer when you do this, raise the fuel pressure to effectivly increase the size of the injectors, then use the fueling computer to pull the extra fuel back from the midrange where its not needed. yes you'll get more peak power with raising the fuel pressure to let you run 1 bar but you'll also kill the torque in the low down and midrange revs by running rich in a back to back comparison of running a correct fueling midrange and not. Tim TB Developments

the correct way to set fuel pressure on an adjustable regulator is to do it at atmospheric pressure, so turn the ignition on and birdge FP and +B on the diagnostic port. this means you can set the base fuel pressure without having the engine running. Tim TB Developments

ok cool i must have misunderstood your reply, i to was just trying to have an informative debate with you not to get pissy. the point i was trying to make is that "stall" is commonly thrown around like "wastegate chatter" and yes it happens because of 2 different things (off throttle to engine bottlenecking) in terms to what the turbocharger is seeing i'm say that its both the same kind of surge just of a different degree, and the term "stall" and also "wastegate chatter" for that matter aren't technical descriptions used and are most of a buzz word. I was just trying to enlighten the thread to show that just because they sound different, and happen at different times they are infact the same thing just of different degree's ie lift off surge (stall) isn't as damaging as full throttle surge, etc etc. Glanza-love, i don't feel we've killed the thread at all, gone a bit off topic yes but debates like this is what expands the knowledge base of a forum Tim TB Developments

very mature rick, just showing your childish nature in this subject, not once have i try to degrade you. Look at what happens in each event in relation to the compressor map of the turbocharger and see which area the airflow sits, left of the surge line. there for both are SURGE! Tim TB Developments

not trying to make myself look anything just doing as you were and correcting a mistake. I've not said i was wrong i'm just saying that there is technically no such thing as stall its all verious degree's of surge. where you were making out its 2 different things and 2 difference causes. Tim TB Developments

i do this for a living so if i wrong i'll admit it, but doesn't give a very good advertisement to loose a debate on such simple engine conditions ;) Tim TB Developments

i've shot an email over to a contact at mine, hes one of the chief designers at garrett who i work with when doing custom specifactions turbochargers, i'll post this reply on the matter. it'll hopefully clear this up so you can understand what i'm trying to say. On everyforum there seems to be a lack of understanding into what, compressor stall/surge, wastegate chatter really is Tim TB Developments

i'm sorry ecksjay but its you who haven't seemed to have grasped the basic facts here, being in the motorsport industy over 13 years i think i can grasp the basic concepts of turbocharger design and behavour. ;) But again we'll go into this really simple for people like yourself. On either term as you put it, there is basically an inability to maintain a set pressure, either through pumping into a closed container (lift off surge) or forcing at full power into a container that can't consume anymore (in the case of an engine with insificiant VE's at the time of surge) now in both case this back pressure generated simply pushes the turbocharger flow characteristics into the surge area of the compressor map. This is why its called surge. because its in the "surge" area of the compressor map. Only difference is that on lift off surge the turbine, is basically spining down on momentum and lower exhaust energy as the throttle body is closed, so is much less aggressive, and full throttle surge which is full exhaust flow and energy, this is why its alot more aggressive and damaging. Like i said in both if you have a boost gauge connected to the compressor housing on both cases you can visually see the pressure build and fall when this occurs. Tim TB Developments

what i meant was high boost levels buddy, you simply don't generate the load on idle to create full boost pressure, so only do this test on the road where you can generate the boost levels needed. Tim TB Developments

basically if your getting the surge (stall ;) ) at full boost then the bov isn't working correctly, if your getting a litter surge, ie fluttering sound from low boost but it vents when lifting off from full boost then its ok Tim TB Developments

ok buddy even though there the same thing, cause and same effect ;) :( but like you say we'll leave it there, your a knowledgable person not knocking that Tim TB Developments

just read that back, didn't mean it to sound so condisending lol Tim TB Developments

oooo so close, you are spot on regarding compressor surge, its basically a back pressure on the turbocharger as the engine can't consume anymore air being provided, so load increases. and yes this is very bad for the turbocharger. It sounds so aggressive because the engine is at full power and gas flow. Now this is where your slightly incorrect, the stall is actually exactly the same thing. Think about what you've said in your own description, even on lift off the turbocharger is still being powered by the exhaust as that will never stop spinning and driving the compressor, so with the throttle body butterfly closed its basically pumping into a closed container, very similar to an engine that can't consume anymore air flow. So again this pushes the gas flow into the surge part of the compressor map. This back pressure is what causes the flutter or chatter you hear upon lift off, but because the engine is basically returning to an idle state when you close the throttle body its much less damaging as the gases driving the turbocharger is dropping off so force spinning the compressor against this back pressure is also falling away. if you connect a boost gauge to the actual compressor housing you can see these pressure spikes exactly the same way as you can see the boost gauge jump around when you see surge at full throttle, its just much less aggressive, but still damaging all the same to the thrust bearings on the turbochager The holes your talking about is called an anti-surge housing, its basically a pressure releace from halfway down the compressor blades to allow the pressure to escape the inducer parts of the compressor blades. Tim TB Developments

i'm open to listen to others so please explain what the differences are and why they happen. Tim TB Developments

i design and build my own turbochargers and i'm a garrett agent, i know what i'm talking about ;) stall and surge are the same thing. Surge is normally refered to as full throttle surge, which is the most damaging but when you lift off this is also surge, it does the same thing its just less destructive, all its doing is adding an increasing load on the turbocharger that mores the flow point into the right sector of the compressor map (the surge area) this is sometimes wrongly refered to as stall or wastegate chatter, when in fact there all the same thing. but i do aggree with what your saying about most bov's, like you said it has to seal on high pressure so needs a spring + boost pressure to do this, and the spring load stops it being very effective at low pressures. now with the hks the boost comes up behind the piston and forces it down onto the seals, instead of hte old style where it trys to lift the piston off the seals. because of this you don't need the high spring pressure to hold it down, so you can use a very soft inital piston for very low pressures. the hks will actually open and very when you've only taken it to atmospheric equalisation pressures inside the engine. Tim TB Developments

he decribed it as chatter through the airfilter. So if this isn't compressor surge upon lift off what is it? also the new generation hks bov's are none adjustable, so it can't be "to loose" the idea of bov preload is only just to compensate for the older type design where the boost is constantly trying to open the bov on boost, the hks design means this doesn't happen as the boost is trying to seal the bov instead of making it leak so you don't need to run such a strong spring. but i do agree with you that a "normal" style bov you will get a little surge below 4-5psi which is normal. Tim TB Developments

why will the car always chatter? (surge) i have a blitz filter on my car and a HKS bov and i get no compressor surge at all. Tim TB Developments

are you comparing this to when you had the airbox fitted? as if the bov wasn't venting properly and causing lift off compressor surge then it wouldn't be auidable with the airbox in place but would be now with the filter fitting instead Tim TB Developments

you'd do better to juse remove the actuator bracket from its position, clock the turbo and then make a new bracet that mounts from the compressor housing clamp ring like the larger GT28's do Tim TB Developments

and who do you think hks gets all its parts from for there turbochargers? the chra's are all garrett on hks turbo's its normally the combination of garrett parts and exhaust housings that make up the HKS turbos I only use garrett turbochargers in my 3sgte turbocharger kits, and wouldn't use anything else now. Like someone said they've got a good collection of broken garretts, all i can say is i've got the same collection of TD turbo's that have fallen apart. for reliability and performance i've not found anything that comes close to the garrett GT kits, but also it depends which models your purchasing. This is a dealer only option that isn't usually avalible to the public but you can sellect which country there made, the usa and japanese versions are much better albeit more exspensive than the ones made in mexico and peru. The only reason i'd say most people on here don't use them is the price, as it all seems to be about money with these small cars over putting the money in for a better part (no offence intended) for an example i use the GT3071r alot in my work, and this is a comparable turbo to the TD06, yes the garrett spools 500rpm sooner and i've had 80bhp more from it with greater torque. But the TD06 is cheaper. Tim TB Developments

the best place for a EGT probe is in the turbocharger collector. there prietty much useless after the turbo. and your looking for no more than 850-875 degree's when at full throttle/boost. Anymore is a sure sign your running lean. Tim TB Developments

well your always welcome to come with us buddy Tim TB Developments

you know its the last one of the year right? Tim TB Developments

cool, be good to see you there. you'll find a good group of people on there, most brached away from the other mr2oc's because of politics and admin money grabbing oh you going to japshow? fancy coming on stand? Tim TB Developments

yeah no probs, the one i tested was a spec1. do the boost test and let me know. I shall also let you know if i come across a bov for you, i had one in the workshop ready and waiting for my glanza, that was off an mr2 as well but we had a break in a few weeks back and the tossers stole that Anyway check out the forum bud, and my email is sales@tbdevelopments.com if you want any more help or advice, have to be careful what i say on the forum as i'm not a regestered trader, well hopefully not yet as i do plan on making some glanza bits once i get mine as a base Tim TB Developments