Well time to start again i think(track car)

[PGiljevic]

http://www.aquamist.co.uk/vbulletin/showthread.php?t=1590&page=15

^ You can have too big a turbo :driving

I try my best to illustrate this with real world examples and tests, I implore people to take their time and read through the information to decipher what is FAST and what is just as FAST with allot less BS :mmmm

For people who don\'t like reading I challenge anyone to show me a 13B fitted with anything bigger than a T04 turbo that is FAST behind an OEM 5 speed gearbox :Talking1

Sure you may make 700bhp in a peak blip (if you are lucky) but on the road it will be a nugget :yes

[Grant Monkhouse]

Always enjoy reading your aquamist thread Peter. Wish I could understand half of the data you put on there. Still Very interesting.

I think my BW turbo is along the same spec as yours. I think mine can flow 70lbs of air/min. Is this roughly the same of yours?

[PGiljevic]

Always enjoy reading your aquamist thread Peter. Wish I could understand half of the data you put on there. Still Very interesting.

I think my BW turbo is along the same spec as yours. I think mine can flow 70lbs of air/min. Is this roughly the same of yours?

I am not familiar with them though almost every week someone around the world is E-Mailing or calling me telling they are running them and want to know what it will be like as a street car..... I just tell them to get something equivalent to a T04Z.

I have shown the above to deliver the goods on average power and outright speed with proven levels of "back pressure" where others seem to just talk about it without any real engineering data to back up the talk. :Talking1

When you get around to testing yours I\'d be happy to hear what you find out, always good to learn of other alternatives to the venerable Garrett T04 standard setter.

I try to make the graphs as esay as possible to understand, the particular one I like is the Stock Std Spirit R Type A acceleration from ~4500rpm to 7000rpm V\'s my T04 equipped car :mmmm less than half the time, half the distance, same weight, same car type, recorded same gearing, and measured double the power across all rpm ranges worth mentioning in a performance car...................... not sure what more sane people could ask for :2Confused

[Grant Monkhouse]

Lee iv just been to AET and asked about the measurement given on the spec sheets for the twin scroll turbine exit size. Just to make sure I would be getting the right one. And apParently the BW turbos are actually designed for agricultural applications.

So they actually come from the factory with a strange v band attachment on them that is no use in a car because of it\'s size. And at AET when a customer orders a turbo they remove that flange and put on a suitable v band clamp. And the correct size is for that turbo is 3".

I asked about the s400 exhaust size and that is a 4.5" v band exit but that\'s what I would expect for something so big.

Just thought you would like to know.

[turbotoaster]

I understand what you have mentioned, think we have discussed it before. The way I see an exhaust gas working is from a little lesson I learned at high school about pressure "a gas or liquid that is in an area of higher pressure will always want to go to an area of lower pressure" to equal itself out. So in theory a staged exhaust, smaller to big, would be good for keeping the velocity up whilst releasing the pressure.

Maybe a couple of variable restrictor in an exhaust would be good? Help buil the pressure to maintain velocity.

I read a person findings on na exhaust systems on his v8, and he found that he could reduce the lengths of the runners and overall length of the exhaust by essentially tricking the exhaust, basically he took the headers to a box where this box acted as though it had vented the exhaust to atmosphere, then had a large diameter exhaust to the rear.

I wish I knew where I read it as it was brilliant for understanding na exhaust systems. I think he benefitted at low rpms more than high. Some of this stuff could be applied over to us turbo guys as if you can achieve great power without them then I beleive the benefits with a turbo would be even greater than just bolting a huge turbo on there.

Ok mate, im afraid you are incorrect on this hypothesis, a turbocharger forces air into an engine and what goes in must come out, that means that the engine is forcing air out of its cylinders/rotor, when you are forcing air through a pipe then the restriction is the biggest problem you will encounter, you should never add a restriction into the system as it will lower the overall VE of the engine.

an easy well used example is a straw...blow through a thin one then blow through a thick one, which flows more air, you are applying pressure and the cross sectional area is working against you.

Now i mentioned in an earlier post that N/A is different than turbos, yes running certain restrictions can help overall torque on these engines under certain circumstances, but then can lower outright power, look at N/A dragcars, you dont see them with exhausts as power is the most important.

you said \'"a gas or liquid that is in an area of higher pressure will always want to go to an area of lower pressure" now while this in itself is true, what do you think a turbine housing does?

It restricts the air into a passage to blow it directly onto the turbine blades which in turn spins. Now at this point you have started to spin the blades, ie the job is done and you want to get the gas out of the turbine housing as fast as possible.

your science now comes into play, you have hot compressed gas around a turbine wheel and wide open pipe under no compression.....what happens.....the gas finds a new low pressure to jump to, the bigger the difference in pressure between the two areas the faster the move......this is the idea of a turbine housing and large downpipe.

After this point the gas has already started to slow down and lose energy so any added restriction in the system will have no effect apart from.

a) increase the pressure in the downpipe hence making the difference between the downpipe and the housing less and slow the gas down

b) slow the air down at the secondary added restriction due to the smaller cross sectional area.

Hope this explains it a little bit for you, just wrote what came out of my head, if you need further explaination, please just ask.

Lee iv just been to AET and asked about the measurement given on the spec sheets for the twin scroll turbine exit size. Just to make sure I would be getting the right one. And apParently the BW turbos are actually designed for agricultural applications.

So they actually come from the factory with a strange v band attachment on them that is no use in a car because of it\'s size. And at AET when a customer orders a turbo they remove that flange and put on a suitable v band clamp. And the correct size is for that turbo is 3".

I asked about the s400 exhaust size and that is a 4.5" v band exit but that\'s what I would expect for something so big.

Just thought you would like to know.

yes, all BW are originally designed for either very larger american diesel tractors or more commonly diesel artic lorries over there.

thats also where garretts originally come from, some people think the t4 on a cosworth or the gt42 was designed for high power petrol engines, nope, again big diesels, its just we found a use for them in our engines.

Personally i wouldnt have wanted AET to touch it because id prefer to make up my own large downpipe that be restricted to just a 3in, especially on a rotary which is known to only use around 75% of the total airflow intake for power and wastes 25% in heat(compared to piston engines) so just to make the same power as a piston engine im gonna have to push 25% more air through the downpipe.

if i was you i would order an unaltered 1.00 t4 twinscroll housing from the cheapest source(maybe US) so you can make a downpipe correct for your application

[Grant Monkhouse]

Dint need to explain it any more. I understand what you wrote. What I wrote earlier was me thinking out loud.

Nice to know someone willing to share turbo knowledge. I will be stepping the exhaust up after the down pipe. Have been reading about the pressure differential on a number of threads, across the turbo. And how people aim for 1-1 or better.

[Panjy]

Ahh, so this is a definate go\'er then
 
Are you going to be entering all rounds? Make sure to post up how you do.
 
Also make sure you post up the actual figure you get for the cars weight, i\'ll be very interested to see how close you get to your 1000kg target

[mjwebb48]

Any updates on this? as I would hope its finished now if your going to make a full season. Good luck on the perreli`s as well!! May be fine for the 4wd boys but on a hot day at brands for example they will go off so quickly on a rwd car!!

[Grant Monkhouse]

First round on 16 th of this month

[RobMatthews]

A lot of talk not much updates? come on pics and progress?

[turbotoaster]

need some more pics before ill do a proper post.

dont worry, when im next down there ill get the pics for you rob.

[turbotoaster]

well the old shell gets stripped down, same to see it all apart but just means we are one step closer to building a monster!!

doors, arches, bumpers and bonnet fitted

rear bumper on

im impressed with the fitment on all the panels +25mm front +60mm rear

new mirrors arrived

the old girl after the carnage

rear stripped down

shows how uneven the floor is, not great for aerodynamics

on a dolly so it can be moved around, sitting next to its bigger brother

engine out, already removed the powersteering after this pic, also all the ignition system pulled out as that will be mounted out of the way to keep them cool

bent oil cooler, gonna run 1 single 50 row cooler on the passenger side to cut down on pipes and free up area on the drivers side for airfilters.

seems my lambda sensor cable had been rubbing, luckily it hasnt broken through the wires, just the outer cabling, just recover and good to go

all stripped off the car, will be all fully cleaned and painted before being put back on, no point putting manky stuff on a clean shell!


thats about it for the moment, i was hoping to get pics of my intercooler setup so will hopefully get them later on this week for people to see.

one step closer to 700bhp/1000kg monster  

[Grant Monkhouse]

are you going single straight away then?

[Grant Monkhouse]

that other 7 looks to b about 12" wider than it should be!! i take it that atomics car?

[turbotoaster]

cant straight away as i havent got enough money to cover it but im building the car ready for it.

4in pipes on the intercooler, dual fuel pumps with seperate -8 lines.

basically when i change over ill just bolt the turbo/manifold/wastegate on, make a pipe from turbo to cooler and a 5in downpipe and then map it.

im still holding you for borrowing your datalogit, dont really fancy doing that type of mapping on the commander.....plus its not like i can do mapping on the way to work anymore

that other 7 looks to b about 12" wider than it should be!! i take it that atomics car?

yes thats jons car, its gonna be a beast, its like mine but with no compromise anywhere, carbon everything and one piece front end........im sure jon would put up a build thread on it if we asked nicely, its a good advert for his business