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REKER
Dodge Dakota
JOIN HERE
8/09/2002
10:33:19
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 Subject: Question about Turbos!
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Message:
Ok, Im not a Turbo Expert, but i do know alot more than the average fellow. My friend has an Automatic 91 GSX Eclipse and he was telling me that an Automatic Turbo Charged car can build boost (spool up) at the line and a manual cant. I told him why couldnt a manual build boost at the line, if u rev it up to where the turbo starts boosting, isnt that making boost??? But i could be wrong. Does anyone know if im wrong or right??.. I just need to get this straight b/c its been itching my nerves.. lol
thanks
ROB
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4wDakota
GenIII
8/09/2002
11:10:53
| RE: Question about Turbos!
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Message:
Turbos kind-of, not totally, rely on load of the engine. So, a maual sitting at the line with the clutch pressed in and revving is just free spinning not really building a lot of boost. while an automatic sitting on the line power braking to load up the torque converter is under load. Engines react differently under load.
It all goes into the programming of the EFI. I have had the pleasure :( of tuning a custom multiport fuel injection system and it can be a pain. Different throttle positions vs. load vs. rpms. must all be set.
Here's a very simplified way of looking at it, for a manual to rev at 2000 takes no real throttle, thus less air and fuel.
An automatic to rev at 2000 fighting the tranny takes a lot more air and fuel and thus a lot more exhaust is produced to spin the turbos and builds boost.
Another twist in the whole mix is that some guys put the wrong torque convertors in there turbo cars and thus don't build up boost and actually run slower because there is no load.
Anyway, chew on that a while :0
Sorry for being so long winded
98 CC 4x4, 5.2 Auto 3.55LSD
3" Body Lift, 1" Torsion Bar Lift, 33" BFG A/T KO's
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REKER
Dodge Dakota
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8/09/2002
11:32:43
| RE: Question about Turbos!
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Message:
ohhh ok... so im guessing im wrong...??
ROB
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Duner
Dodge Dakota
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8/09/2002
13:01:39
| RE: Question about Turbos!
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At least on mine anyway...... no load = no boost.
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sandman
Dodge Dakota
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8/10/2002
12:35:31
| RE: Question about Turbos!
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Thermal energy is what drives the turbo heat=boost!! So while your friend might be partial right. The problem with all this is that autmoatic waste alot of power!!! A properly set up turbo system will have little lag so I think it is a mute point.Trying to set up an automatic to survive with a turbo can be very difficult!!!!You also have to comprimise your waste gate and blow of valve setiings to spare the Turbo between shift on the automatic. Impeller cavatation is a much more common problem on OEM automatics in a Turbo car or truck!! You can much more agressively with a manual trans.
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Bernd
*GenIII*
8/11/2002
10:16:46
| RE: Question about Turbos!
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Same goes for centrifugal superchargers...it's based on load (partially, but they're also RPM based). Automatics put a load on the engine (especially when your "loading up the converter" at the lights) which helps build boost.
1997 Dodge Dakota SLT - V6
Supercharged/Intercooled @ 10# w/Nitrous
14.55 @ 96.01mph
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