I wonder if your line was bad maybe. Mine 3an will shoot oil clear across the shop.

 

Mine is just 1/8" pipe, but 3/8 isnt going to hurt. Havent heard anything bad about the exa pump, got mine from Rbracing though.

 

Maybe what he is doubting is a 66mm turbo being capable at all to supply the same amount (volume) of air to be able to create the same amount of pressure (boost) in the engine as a larger 80mm turbo? Thats where compressor maps come into play. I dont think it could, certainly not at the same density and spinning the snot out of it. I wish I had a shaft speed sensor on the old tc76 and the new BW so I could have compared, way too much $$ though.

 

Negating frictions and whatnot in the turbo, the smaller compressor wheel makes no more heat than the large one. The heat comes from compressing the air, and thats it. And this has nothing to do with VE. In this case, its called isentropic efficiency. But I've never seen a compressor map with IE on it lol..

Bottom line, the faster you can make boost, the smaller the turbo you can run. Ever wonder why the supra dudes make like 800rwhp on a 68mm, but our trucks with V8s can't even touch 600 with a 68? Its all about the rate at which air is demanded from the turbo.

Sucks to hear that

 

Supra guys run have HALF the engine size and double the boost.. it takes more air volume to feed a 4.8 or 5.3l then a 3.0 Lots of things talked about and things in this thread.. I have tested 5-6 turbos on the same combo over a 2 year span all t6 S series from Jose@FI 85,88,91 to Precision thumpers 94,98,101 ... All done with a number 3 oil line.. but I had a Rex engine and able to make over 60psi of oil pressure at idle ! You guys are close in what your looking at but still missing a few major keys Manifold pressure is just a number there are 3-4 more factors then just that

 

If you'll watch dynamic cylinder air mass versus dynamic airflow (or the toyota equivalents) after going WOT, you will notice that the pressure ratio vs airflow path taken across a compressor map is very different from our larger V8 engines with the same turbo. A supra will rise much more quickly in the pressure axis, simply because the instant you go WOT, the 4.8/5.3 is demanding a lot more air than the 3.0 hence making more 'NA' power . Turbos want to begin pressurizing the air before a lot of airflow is demanded...otherwise the turbo VE falls off too quickly to continue making boost. I have verified this

 

I understand that compressing air, or any substance creates heat, but Im not buying that a turbo spinning like hell isnt creating heat too... Along with gaining enough flow through the turbine to raise the ve of the engine to trap an extra 10mph with my turbo swap, my charge temps dropped by Id say a good 15% or more maybe while in boost and in vac.

"A side effect of creating boost is heat (hence the need for a chargecooler). A small compressor wheel spinning at its upper limits may be able to create more boost, but a significant part of it is from heat not from actually compressing more air. It is simply "beating" the air harder. A serious downside is the increased speed that the small compressor wheel must spin. "

 

Wheel speed plays a part in choosing a turbo, but its normally not an issue on a well selected setup. You will sometimes see compressor maps with speed lines showing the wheel speed at a given pressure ratio and air flow. This is where the fancy billet, ball bearing compressors come in hand; they can tolerate a much higher speed. You would eventually have shockwave formation on the blade tips from it approaching sonic speed. If shockwaves were to form it would have chocked flow and would never flow more air even with an increase in wheel speed. This is what the choke line on a compressor map represents.

What I think you are reffering to is turbos operating near the upper limits, in which case of course they are making more heat because they are no where near their ideal efficiencies. What I am reffering to hear Most turbo makers dont even bother posting maps with efficiency islands below 70% because if your turbo is operating there you have the wrong turbo for your application.

Jake, you always see turbo maps with isentropic efficiencies on them, what do you think those efficiency islands are?

 

If i cared about Displacement i wouldnt have a turbo! Now the good luck, ive gotten my truck in the mid 10's with my own tuning and built the whole truck why do i need luck keeping it together, Big Power will eventually = Broken parts anyhow, like i said ill get some solid numbers for ya from going to a 88 mid frame a 91 large frame at 15#'s just stay tuned

 

No, I haven't seen any IE maps. I would like to see some...but AFAIK it costs a shitload just to get the VE maps. I don't really expect to see any isentropic data on compressors.