Straight Bolt On Turbos

[GC8E2DD]

 vorigan said:

Not according to the special ones on here its the be all end all, but i totally agree with you no offence taken glad someone else can smell the coffee.

I understand that a lot of this discussion (and others) might seem like a personal affront to your work, but I (and a lot of others) are mostly on these forums to learn. The beauty of things like back to back dyno sheets, even for the uninitiated, is that some kind of conclusion can be drawn in a controlled environment with the least number of variables. The closest thing to a scientific method without having to have specialised test rigs for benching turbos themselves in isolation. It would be nice to see some discussion regarding the more knowledgeable people's (such as yourself) theories on the different results obtained in these dyno charts.

Some of the misconceptions about turbo performance in general might be dispelled with some cordial passing on of the collective knowledge regarding the specifics of turbo anatomy and the likely results of various modifications and alterations to turbo components and geometry. Obviously I'm not talking about trade secrets; more the theories behind certain turbo modifications like altering exhaust/ inlet housing size with respect to each other, cutting back turbine wheels etc. There is a lot of information on the internet obviously, but it is often at the extremes of either gumby descriptions or excessively technical and aimed at the kinds of people that design and build turbos. Perhaps the subject is just too technical for the average layperson.

[WRXONP]

Hey steve . Whats the most simplest explanation you can give on a cut back exhaust wheel ? And what does it achieve ? Is it cutting the blades down on a precise angle or am I well off ?

[sultan]

 vorigan said:

hahaha cheers dude you mean my grandads 5 series bmw? na its just all s*** yourve seen and that tiny little cheap chinese turbo going on it itll never work like that 600kw holden ute i showedu on 12psi na just all bulls*** and hear say.

did you have a look at me being a drop kick in me 5hp briggs kids kart?

crazysteve.mov imagine if i knew what i was doing and it actually went well?

all those tropheys on my shelf was from being a dick, i should apply myself one day :D

yeah i saw the vid, i see what you mean by nearly launching yourself into the wall. doing a donut over a 2 metre radius looks hilarious haha

[Optical]

 pappu']

[quote name='Optical said:

vf34

url=http://img88.imageshack.us/img88/9249/vf3420.jpg]http://img88.imageshack.us/img88/9249/vf3420.jpg[/url]

what mods were done to the v7 - thats bloody good bro!!!!

Was on a version 4 STI, just like the one Steve posted of his modified oem turbo, except this turbo was not modified and is making more power everywhere

As Steve as recently learned though, you can adjust the dyno parameters to make boost come on early or late, you can also make it read whatever power you like. So we must agree posting dyno sheets is a hapless cause.

I also would like to hear Steve's analysis on the three compared turbos (one his) that were tested in controlled conditions as we know dyno discrepacy can be eliminated. Nothing like learning from the experts

[vorigan]

 Optical']

[quote name='Optical said:

vf34

url=http://img88.imageshack.us/img88/9249/vf3420.jpg]http://img88.imageshack.us/img88/9249/vf3420.jpg[/url]

what mods were done to the v7 - thats bloody good bro!!!!

Was on a version 4 STI, just like the one Steve posted of his modified oem turbo, except this turbo was not modified and is making more power everywhere

As Steve as recently learned though, you can adjust the dyno parameters to make boost come on early or late, you can also make it read whatever power you like. So we must agree posting dyno sheets is a hapless cause.

I also would like to hear Steve's analysis on the three compared turbos (one his) that were tested in controlled conditions as we know dyno discrepacy can be eliminated. Nothing like learning from the experts

If your going to turn into total f***wit like the others ill treat you accordingly( i was told you better than the others), as for the comparring turbos if you read just a tiny little bit closer many get differant results from similar setups and alot cant get even close.

Based on your analise of these units lets compare the why the 3076 was crap compared to what we did over 300kw and yet we ran 3 psi less? as for the units being close i think a blind man can see theres a 5psi spread between them at differant points and depending on the rate of gain( 1psi plus or minus =?) will can alter that picture dramaticly but hay as you said dyno sheets are a crok so i guess mine is just as much a lie as what you and others have posted.

So maybe the reason mine was a tad low is the same reason the 3076 didnt cut it either,it too could be a lemon thus spend 8k or so to make slightly better bargin.

Differant or even the same turbo will give differant results on differant cars, heads, cams, compression,cooler,piping, intake,rod angle,crankcase volume,manifold,headers etc etc etc all contribute to the outcome.

So take your pick to what could alter the outcome talking with PSBM and afew others they too have had lemons that no matter what you do wont make numbers,get over it and move along or open your wallet.

We can only work with whats presented to us based on customers budget to which kills alot of their dreams and expectations, in saying that what would have that dyno sheet you put up looked like if it had a tricked up turbo on it?

So lets take them to track and see what it all adds up to or just get over the fact there is differance based on many contributing factors or just screw with the dyno.....A.

To which many travel from dyno to dyno to find that warm fuzzy feeling for a result to never take the car to the track ( or write it off on the road to where they shouldnt be racing in the first place) or sit in traffic 3hrs a day with dyno sheet glued to the back window "hay look what ive got" or jump on a forum !!

[sultan]

i think comparing steve's modified vf23 to a vf34 (rare as fuck and pricey) and a $2000 garrett is a bit of a stupid comparison. i don't think steve markets a service that he can turn any turbo into a 300kw turbo. he'll rebuild and modify a turbo that YOU provide him to get better performance out of it.

how about you compare his vf23 to a standard vf23 instead??

[johnny5]

 sultan said:

i think comparing steve's modified vf23 to a vf34 (rare as f*** and pricey) and a $2000 garrett is a bit of a stupid comparison. i don't think steve markets a service that he can turn any turbo into a 300kw turbo. he'll rebuild and modify a turbo that YOU provide him to get better performance out of it.

how about you compare his vf23 to a standard vf23 instead??

yea or one thats been modded from another workshop put things on an even playing field

[GregNZ101]

What has been done to the car with the vf34, as it seems to have 10% more power than you would expect! Also funkytown why were you unhappy with getting 232wkw with a murch turbo, as from the graphs that i have seen your average vfxx turbo gets 210-220wkw so a gain of 15 odd kw would be quite good for just a bit over $1k, i know some people get higher but not the average?

[sultan]

steve's work on the vf turbo is much less than 1k. it's when using garrett compressor wheels on bigger turbos that it goes to a bit over a grand

[vorigan]

 johnny5']

[quote name='sultan said:

i think comparing steve's modified vf23 to a vf34 (rare as f*** and pricey) and a $2000 garrett is a bit of a stupid comparison. i don't think steve markets a service that he can turn any turbo into a 300kw turbo. he'll rebuild and modify a turbo that YOU provide him to get better performance out of it.

how about you compare his vf23 to a standard vf23 instead??

/quote]yea or one thats been modded from another workshop put things on an even playing field

forgive if im wrong but im not awear of any other shop in nz doing what i do but your are correct, the max i would expect to see from my upgraded is 240kw so it was 8kw down yet with his 3076 versus my crap 3076 on 3psi less turbo for turbo hes is close to 50kw down!!

must be the dyno or photo shopped dyno sheet.

[WRXONP]

Steve I love your serious sense of humour . . . . Makes this a dam good read

[vorigan]

 WRXONP said:

Steve I love your serious sense of humour . . . . Makes this a dam good read

hahaha cheers in person i just punch people that piss me off saves a ton of typing

And those who dont like what i make or say dont use my units and get over it, suck ya heads in and show us hows its done or live inside a pc for the rest of your life cause thats the real world :-*

HTR969

And this is the end result of a crappy built under performing mse turbo.

RIP stacey a top guy that will be missed by many let stace have the last word......

[WRXONP]

Hey steve I asked before but I think you missed it . Could you do a really brief explanation of a back cut exhaust wheel and what it achieves ? Just curious been hearing of it for ages

[GC8E2DD]

Is it possible to actually have a sensible discussion on Straight Bolt On Turbos? How many pages can this West Side Story dance off go on for?

[WRXONP]

Its great stuff !

[Optical]

 vorigan said:

If your going to turn into total f***wit ...

pardon me for asking. (for the record i can be a total f***wit at times, but im genuinely trying to learn here).

Correct me if i have misinterpreted you, but i think what you are trying is different setups produce different results and/or dyno differences? As mentioned, in this case it was the same setup and only the turbo was different so we can eliminate the dyno from consideration. You could call it a controlled environment.

I dont really want to 'take my pick' as to the reason, it's your product. Are you not at all concerned by this? The exact power numbers dont matter, it's the relative differences here that are relevant. So again, what is your expert analysis on why this was?

[vorigan]

 Optical']

[quote name='vorigan said:

If your going to turn into total f***wit ...

/quote]

pardon me for asking.

Correct me if i have misinterpreted you, but i think what you are trying is different setups produce different results and/or dyno differences? As mentioned, in this case it was the same setup and only the turbo was different so we can eliminate the dyno from consideration. You could call it a controlled environment.

I dont really want to 'take my pick' as to the reason, it's your product. Are you not at all concerned by this? The exact power numbers dont matter, it's the relative differences here that are relevant. So again, what is your expert analysis on why this was?

I apologize net is great for interpriting how things come across,

Concerned about what? its 8kw short of what its max is meant to be for that and how its tuned when it leaves my shop is out of my control as your seen by a back to back we did that wasnt the case nor was the v7 and v8.

Im repeating here each turbo regardless or whos will have differant effects to some point on any vehicle, so in fairness you would say 8kw isnt that bad as for the mid range who knows how that was being controlled was the gate tied? preload been changed? again regardless of the back to back as per yourve pointed you still have 3 differant units.

again explain why the 3076 is 50kw down for 3 psi more?

Now if it realy is the same motor theres more than likely something it doesnt like from one to the other, you need to tune the base setup to 90% of what its capable of then change to the next unit and do the same to find the limitations or gains.

The little details will make a big differance thus take your pick to which thats the job of the dyno operator to find these.

You cant compare a 400hp unit to a 525 that isnt by no means remotely the same( comp wheel turbine and housings totaly differant),52lb/min versus 40lb/min its not hard to work that out.

So if we bolt a t51r on and ran the same base tune and boost what do you think that would look like?

Theres 5psi differance between the 3 at points thats not an even playing field in anyones books.

Every upgraded thats done thats big 16g uses a genuine MHI wheel you will never see the power of a 3076 out of them and ive never promted that, its designed as mild upgraded as s straight bolt in nothing more nothing less.

Subs are know for boost drop off on the topend everyone knows that thus all the posts asking to improve then we have others that dont drop off and yet were talking the same stock vehicle with no upgraded turbo, explain that.

As for your vf34 looks like a good effort now theres also alot out there that cant get near that result for the same vehicle again explain that.

[sultan]

this all seems like weighing a 2kg brick, and a 3kg brick, and asking why the 3kg brick is heavier

[Optical]

The gt in question was a 3071 (not 76), and had a custom turbine housing that I understand is smaller than a gt30 0.63. (Built by turbo dynamics in the UK). So the power level is about bang on target, certainly agrees with the compressor and turbine maps.

In each case the turbo was custom tuned to peak it's potential. If it were running an oem ecu or the same base tune then yes results would look wierd. But this is not the case here.

The boost choosen was the level at which peak torque was made, as any good tuner will do. So the level doesnt matter. Either the turbo couldnt run more, or it didnt make more power if it could.

What i'm wondering is if by back cutting the turbine wheel you limit the ability of the wheel to extract power from the exhaust gas, thus incresing boost threshold. Couple that with (maybe?) a higher intertia compressor wheel and the boost threshold becomes even higher. That would explain the large amount of extra lag.

I understand the back cut is done so EGBP is reduced and VE will increase at higher rpm. So couple that with a higher flow compressor to make the most of the increased flow potential, makes sense. But for whatever reason that power potential isnt being realised, or at least not to the point where the extra 10kw peak power justifies the increased boost threshold and narrower powerband.

Perhaps a better option is to put vf3x compressor wheels to older vf2x turbos? It's still unclear what performance increase the back cut gives though. Do you have a dyno (of the same same same) comparing a back cut VF vs a non back cut turbine and with the same compressor?

Also note none of these turbos are mine and I have no bone to pick. This info is out there for everyone so i'm just interested.

[vorigan]

 Optical said:

The gt in question was a 3071 (not 76), and had a custom turbine housing that I understand is smaller than a gt30 0.63. (Built by turbo dynamics in the UK). So the power level is about bang on target, certainly agrees with the compressor and turbine maps.

In each case the turbo was custom tuned to peak it's potential. If it were running an oem ecu or the same base tune then yes results would look wierd. But this is not the case here.

The boost choosen was the level at which peak torque was made, as any good tuner will do. So the level doesnt matter. Either the turbo couldnt run more, or it didnt make more power if it could.

What i'm wondering is if by back cutting the turbine wheel you limit the ability of the wheel to extract power from the exhaust gas, thus incresing boost threshold. Couple that with (maybe?) a higher intertia compressor wheel and the boost threshold becomes even higher. That would explain the large amount of extra lag.

I understand the back cut is done so EGBP is reduced and VE will increase at higher rpm. So couple that with a higher flow compressor to make the most of the increased flow potential, makes sense. But for whatever reason that power potential isnt being realised, or at least not to the point where the extra 10kw peak power justifies the increased boost threshold and narrower powerband.

Perhaps a better option is to put vf3x compressor wheels to older vf2x turbos? It's still unclear what performance increase the back cut gives though. Do you have a dyno (of the same same same) comparing a back cut VF vs a non back cut turbine and with the same compressor?

Also note none of these turbos are mine and I have no bone to pick. This info is out there for everyone so i'm just interested.

first off this was never said "In each case the turbo was custom tuned to peak it's pote.ntial" it was meant to be back to back bolt in no other changes guess that was over looked :

Secondly the way i tune isnt just going for pike torque( you would run out of power pretty guick just using that method), you would measure the backpresure before the turbine and compare that to the comp end to establish what fall over first, did it need a change in cam timing,ran into knock( if were talking about the same tuner i spoke to knock was an issue) etc etc also temp intakes also so a better picture than whats being shown here.

Torque drops off well before peak power as per most engines unless your running a t51 thus your not tuning to its full possiable outcome.

The compwheel isnt that big 68/47.5 compared to stock its bugger all bigger as for the lag the graphs ive put up shows a differant story, again if the units gate isnt right or rate of gain for the boost controller etc etc to which if it was a link there boost control isnt very good even link say its 75% ok will effect it.( i have customers that run PRS and they dumped the link due to this issue)

The graphs as ive shown backs up what we spent so much time testing before joe blow got to use it,many have a many are very happy.

I send alot of bolt on mse units to aus to where they take out the avo so called bolt in and replace with mine due to the fact they lack responce, the head tuner for motec Paul has tuned afew his words were it was more responcive than stock give him ring dont take my word for it.

Now i did ask you to explain why guys with stock vf3x cant get close to what others are getting stock even with changing tunes, this is pretty comon with subs so just maybe theres good ones and bad ones and i or the tuners i use dont make the cars we just try to our best with what rolls thru the door.

I have seen many times car "a" stock run against car "b" with good mods done get its butt kicked,you could bring driver into this as with other possiable errors but doesnt explain with the power differance why it couldnt even match the same topend yet the dyno tells another story.

Big power figures of a dyno dont always reflect a fast car,the backcut has been standard practise for many years to help aleviate backpresure for a stock turbine hsg or wheel as im sure your awear they all share the same turbine wheel and factory or after market dont have a bolt in rh6 turbine which would be nice.

The back to back testing with or without a backcut we found a small increase in power but what it showed the most is the reduction in backpresure reduced exhaust temps allowing more timing to be used be knock and everyone knows subs are prown to knock at the best of times and theres many posts on here asking how to remove it even on stock setup.

We found tuning grp n that tuning each cly( using motec) we found one gave the biggest isssue and adding fuel or ruducing timing we could lean on it harder and i dont mean boost, but repeating that for each cly we gained 30hp for no more boost.

I think we just has to be accepted that each car responeds differant to the next, if you use my upgraded on a car struggling with a stock vfx to go past 210 then gets 225 with mine but wont go further its still a gain regardless even if it didnt hit the 240 mark so i guess theres alot more to it than the turbo.

I think alot need to spend a week in a dyno shop watching and seeing what realy goes on and how we have to try and make a silk purse out of cows ears,thus with all these net pros that are such critics i would love to see how they deal with issues and the answers to fix them and not on a forum.

The answer your after based on whats meant to stock from car to isn the case, we have pulled down many engines to find from side to side the deck heights were differant chamber cc was differant and cam timing marks stock didnt line up being half a tooth out, now the guys that do ken blocks engine make adjustable idlers to allow a slight adjustment to put things back to factory and seeing another 30plus hp for there efforts.

And theres meant to be no differance between engines? yea right would make a good bill board.

So you want an answer? maybe your not seeing it or looking for a easy one well there isnt just keep testing and trying is what everyone does.

So lets take your v34 turbo off and put it another that cant make anywhere near yours, wonder what would happen try it and lets know but everything has to be the same no retune just to be fair.

Usless info here i spent the afternoon at alltech we went thru all the OEM documents from Garrett, holset, mhi, ihi,borgwarner and couldnt find one statment referring to the compwheel to exhaust wheel ratio to what is max allowed.

So we measured my little upgraded thats been said the wheels to big and that was a .77 ratio, stock was .87, 3071 was .8, a 3082 was .7.

There is however a ratio for manufactoring a compwheel that borgwarner dont recomend you go past of .8 theres no refferance to anything else unless you guys have access to documents the biggest turbocharger place in nz doesnt?