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+--- Thread: Non vgt discussion (/showthread.php?tid=10732)
Non vgt discussion - jaysoto - Today
I'm well aware that for the most part everyone here is pro vgt. Myself included but I was driving today and realized that my 485 isx feels very similar to all the old trucks that I've driven (not bad) with regular turbos. The only real difference I noticed is with the exhaust braking along with the jakes helping slow everything down. As far as I can tell from a driving perspective other than that there is not much of an advantage over a regular old school turbo. Not trying to start an argument just my unbiased opinion. I love the exhaust brake. Really does a great job with engine braking. But as far as everything else it feels identical to anything else I drove. I especially noticed it between gears I get the same puff of smoke and the same lag I got with my other trucks. Actually I think my old Mack e7 would spool faster. So here's the big question besides the exhaust brake does anyone have any real downsides to a non vgt, and I mean appropriately sized and properly tuned not some hack job I mean if you really took the effort to do everything as perfectly as it could be done (which I'm sure would cost well above what the stock turbo does) would it really be worse than the vgt. Strictly looking at it from a factual standpoint
RE: Non vgt discussion - mikkhh - Today
Well if you like old inefficiant things and headaches you can buy N14.
If you like newer non VGT unreliable and expensive things you can buy S13 engined truck. Those things are popular in Europe and it is not uncommon to see them fail at 200 000 miles or less (spun bearings, broken crankshafts, cracked heads)
VGT turbo is more efficient than non VGT, UNLESS somebody uses lots of timing advance and sacrifices engine life in return.
RE: Non vgt discussion - jaysoto - Today
(Today )mikkhh Wrote: Well if you like old inefficiant things and headaches you can buy N14.
If you like newer non VGT unreliable and expensive things you can buy S13 engined truck. Those things are popular in Europe and it is not uncommon to see them fail at 200 000 miles or less (spun bearings, broken crankshafts, cracked heads)
VGT turbo is more efficient than non VGT, UNLESS somebody uses lots of timing advance and sacrifices engine life in return.
Well I don't think any of the old engines were headaches or inefficient. There's a reason there's so many n14 Cummins 60 series detroits and c15/3406 cats still out on the road or even the signature 600 Cummins. People love them. I don't see and better mileage out of this isx than I did my old engines. Just my experience
RE: Non vgt discussion - tree98 - Today
There are people on this forum that get 9+ mpg on a daily basis hauling freight all over the country with an ISX, you weren't getting that with the dinosaurs of yesteryear.
Your not going to feel any kind of difference while driving a truck that has a vgt. Its just that the vgt sets the air fuel mix precisely for proper combustion. And because it self adjusts its like having the proper sized turbo for all RPM and load demands. The old turbo's were a compromise because your burning fuel unnecessarily while waiting for the turbo to spool. Or a smaller quicker spooling turbo to help at lower loads but now you can't boost high enough on top, you get what im saying?
Hopefully you didn't throw your vgt away and are now trying to convince yourself that you didn't make a HUGE mistake.
RE: Non vgt discussion - marek4792 - Today
Only a wastegated turbo would work somewhat well, with compromises mentioned above looking at what cummins uses in markets outside of North America that doesn't require EGR, but the point still stands VGT will always be more precise through the rpm band compared to any fixed vane wastegated or not... Don't frick with it...