turbo advise needed
Turbo Mini Forums

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

its also worth me mensioning 6bhp loss was because of the incorrect timming caused by the decomp plate, hence why i run an adjustable pulley

jason

so effectivly you are running a squish of about 4.5mm?

I would not be suprised if that accounts for the difference in power due to the burn changes.

I for example am running .8mm squish, and i think the majory of engines here run somthing around 0.8-1mm.

Of course different engines like diferent things...:?

hi jason , i have the 188 bhp at 16 psi mini ,on a gt17 .
id think it would work well for you .

that 188bhp was on 15 degrees of timing so very retarded ,and also with a hot intercooler since there was no cooling flow through it .. with a fan on the ic and a bit more timing id estimate 200 bhp on 16 psi.
ill find you a graph of boost rise /rpm

here you go


bhp versus boost
122bhp 5.5 psi
144bhp 9 psi
168 bhp 12psi
183 bhp 15 psi
188bhp 16 psi


regards robert

Edited by robert on 28th Feb, 2010.

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

thankyou robert, very impressive!!

it gives me something to think about.

I think that the advantage of the A series over a lot of modern engines is the choice of cams available. 50 years of development has to count for something.

What choice of cams are there for the 8v fiat?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

just out of interest thought you may like this, ive been doing the math to work out my current lb/min at my boost pressure to plot it acuratly on the map.

Pressure Ratio (14.7+15)/14.7 = 2 P/R

CFM = 1.25x6000x85x2 /5660 = 225 CFM

225/14.27 = 15.7lb/min

plotting that on the Compressor map from the GT1544 it puts me of off the map over the choke line at 210,000rpm.
This would exsplain the huge inlet temps and lack of gains above 0.8bar. Even the GT1544 with the 44mm wheel would be very unefficient at this level running at about 70% efficiency!

glad i found this map ive been looking for one for some time! thanks guys

jason

Edited by 1250cinqturbo on 2nd Mar, 2010.

Just as a point of reference, I calculated my engine will consume 12.3 lb/min (I can't remember the pressure ratio off hand) and I will be operating on the peak efficiency of the bigger GT1544. It does sound like you need an upgrade, probably on the turbine side too.
Did you see the interpolated map for the GT1752 to see where you lie on that?

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

I did a little searching for chinq turbos and i read that anything over 1bar or boost and the standard pistons turn into cheese.
Also had personal experience of the oil strainer becoming blocked, blocking up the oil jets on the cam and rapidly wearing it down.

As you mentioned a change of pistons to change the compression ratio needed would surley be a better option.

the 17's we use are off saab 93's (as you have probably read)

unfortunately they arn't that common, but your probably looking at a couple of hundred for a good used one.

http://cgi.ebay.com/ebaymotors/Rebuilt-Gar...sQ5fAccessories

such as this??

thanks

jason

Edited by 1250cinqturbo on 28th Feb, 2010.

that's the puppy!

this is so tempting, i just no id have a nightmare fiting it, my current down pipe is so close to the rad and oil filter, and looking at the circle flange on the GT17 its huge, making something to git it and then to fit to my down pipe would be hard...........hhhmmmm

I've found its best to buy the bits then MAKE them fit PMSL.

where there is a will there is a way....

i surpose your right, it makes sence for me to go to the GT17..........i didnt intend on the car being off roaf for two long but i guess it might end up that way haha

My car is my daily driver and it's been off the road for 18 of the last 24 months!

On 12th Nov, 2009 Paul S said:

I think Gary OS has taken over my role as the forum smart arse

its always that way...

mine was of the road 10 years because i had to change a radius arm.... turned into a saga.... lol.

there must be a way of getting it in though, is there any room between the turbo and block? can you grind any webbing off the block to make some room? can you move the oil filter?

problem is this mad little car is my dailey car to work 9 miles from where i live through town haha.
thankfully on the cing the rad can go to the other side of the car, the oil filter can be replaced by a remote item and the block........well id rather not touch that haha.
it can be done but it may take some real effort and the car is in works lock up (im a mechanic)

im going to ask midland turbos if they stock a GT1752 on the shelf,,,,but how many variaents of the GT1753 are there??