Turbo theory
02-14-2011, 11:59 AM
#51
I did a bunch of calculations in an accurate engine dyno simulation software (EAP).....
At part throttle (same timing same AFR) they consumed basically identical amounts of fuel (im replicating part throttle by reducing throttle body CFM).
The big difference:
Where the N/A motor would take significantly more CFM to produce the same amount of tq (and therefore hp). For 2500 rpm and 300 ft/lb of tq, an N/A 5.3 (free flowing exhaust too) would take 400 cfm. SIMPLY adding a GT 4088 (70mm turbo) it only takes just under 200 cfm.
What does this mean? Far fewer throttle position changes...IE much less fuel from an "accelerator pump" in carburetor terms.
At part throttle (same timing same AFR) they consumed basically identical amounts of fuel (im replicating part throttle by reducing throttle body CFM).
The big difference:
Where the N/A motor would take significantly more CFM to produce the same amount of tq (and therefore hp). For 2500 rpm and 300 ft/lb of tq, an N/A 5.3 (free flowing exhaust too) would take 400 cfm. SIMPLY adding a GT 4088 (70mm turbo) it only takes just under 200 cfm.
What does this mean? Far fewer throttle position changes...IE much less fuel from an "accelerator pump" in carburetor terms.
02-15-2011, 04:43 PM
#52
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I have to drive 8 hours back to houston to install the turbo, I'll get my highway MPG all the way there and then on the way back when I have the turbo installed I'll measure highway MPG again. This will happen around March 11th lol
I hope my MPG doesn't suffer extremely bad w/ the turbo. From what I have heard a turbo increases MPG, all I can do is cross my fingers
I hope my MPG doesn't suffer extremely bad w/ the turbo. From what I have heard a turbo increases MPG, all I can do is cross my fingers
02-15-2011, 04:49 PM
#53
I have to drive 8 hours back to houston to install the turbo, I'll get my highway MPG all the way there and then on the way back when I have the turbo installed I'll measure highway MPG again. This will happen around March 11th lol
I hope my MPG doesn't suffer extremely bad w/ the turbo. From what I have heard a turbo increases MPG, all I can do is cross my fingers
I hope my MPG doesn't suffer extremely bad w/ the turbo. From what I have heard a turbo increases MPG, all I can do is cross my fingers
If you want to really test it, remove the wastegate (hopefully its big enough/angled right to never make boost)....and drive a route. Re-install the WG and try it again.
02-15-2011, 05:37 PM
#55
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Not a completely valid test, as you may go more downhill in one direction, and more uphill in the other.
If you want to really test it, remove the wastegate (hopefully its big enough/angled right to never make boost)....and drive a route. Re-install the WG and try it again.
If you want to really test it, remove the wastegate (hopefully its big enough/angled right to never make boost)....and drive a route. Re-install the WG and try it again.
the WG idea is pretty clever
02-16-2011, 02:35 PM
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hey even t3's can make 1000 hp .
although im sure my back pressure is quite high as im having some issues controlling low boost either that or im outflowing twin 44mm tials wg's.
although im sure my back pressure is quite high as im having some issues controlling low boost either that or im outflowing twin 44mm tials wg's.
02-16-2011, 02:45 PM
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possible as the angle of the qg is great from the collector but its closer to one primary than others so it may be going around it.
doesent really matter as its only trying to run 12 or less psi . at 15 everything is good. so at 20 it should be fine. cant wait to find out what happens with the gtx-35's or something similar.
doesent really matter as its only trying to run 12 or less psi . at 15 everything is good. so at 20 it should be fine. cant wait to find out what happens with the gtx-35's or something similar.