V8srfun
Well-known member
- 423
- 538
- 93
- Location
- Altoona pa
The problem with those calculators is they do not always account for total engine flow but base their figures off of general engine efficiency statistics. In the case of the ld series engine it is not as efficient as many of the other engines that the calculator is used for.
Being that I am not planning on using what ever turbo I choose for max effort but rather just be a little more efficient than the 50 year old technology that the gov used. My main focus is getting a turbo that is not so big on the hot side that it is laggy and I loose all of the efficiency that I gained with a modern turbo. I would rather a turbo that is a little small on the hot side than to large. A turbo that is marginally to small on the hot side will only cause a lack of power at the top of the rpm range but will actually be more responsive down low. For example if you have driven a modern 4 cylinder turbo car or suv that has not been modified you would have experienced what a undersized turbo feels like. They are incredibly responsive on tip in but fall flat up top as they just can’t move enough air to make any more power. With a 4 cylinder that can turn 6500 rpm you won’t care if the last 1500/1800 rpm doesn’t make any more power because you have so much to work with. But with a ld that has a useable rpm range of 1700 rpm or so I can’t afford to put a turbo on that is laggy and does not respond quickly. Especially with a diesel that needs air to burn the fuel and keep egt’s in check you want boost right away not 200 rpm later.
this is my theory at the moment as more research is done my thoughts may change but for now it makes sense.
Being that I am not planning on using what ever turbo I choose for max effort but rather just be a little more efficient than the 50 year old technology that the gov used. My main focus is getting a turbo that is not so big on the hot side that it is laggy and I loose all of the efficiency that I gained with a modern turbo. I would rather a turbo that is a little small on the hot side than to large. A turbo that is marginally to small on the hot side will only cause a lack of power at the top of the rpm range but will actually be more responsive down low. For example if you have driven a modern 4 cylinder turbo car or suv that has not been modified you would have experienced what a undersized turbo feels like. They are incredibly responsive on tip in but fall flat up top as they just can’t move enough air to make any more power. With a 4 cylinder that can turn 6500 rpm you won’t care if the last 1500/1800 rpm doesn’t make any more power because you have so much to work with. But with a ld that has a useable rpm range of 1700 rpm or so I can’t afford to put a turbo on that is laggy and does not respond quickly. Especially with a diesel that needs air to burn the fuel and keep egt’s in check you want boost right away not 200 rpm later.
this is my theory at the moment as more research is done my thoughts may change but for now it makes sense.