Not diesel. The most ridiculous turbo system - Page 2 - PeachParts Mercedes-Benz Forum

t walgamuth · #16 03-19-2006, 04:56 PM

i realize that.

but turbos increase back pressure. nothing is free.

i suppose that turbos are simpler to maintian since there is no drive mechanism. but as far as effeciency, i dont think there is much difference.

if there were, dont you think the dragsters would use turbos?

there were a few back in the sixties but they didnt last. i mean they just disappeared.

tom w

nuckingfuts · #17 03-19-2006, 05:06 PM

I've seen ten or twelve sleds with the turbo in the rear. The sleds are setup like that so the air is nice and cool by the time it gets to the motor without use of an intercooler. I don't see the use of that on this car as it has no snow to cool the air.

imdavid28 · #18 03-19-2006, 05:10 PM

Quote:

Originally Posted by t walgamuth

if there were, dont you think the dragsters would use turbos?

They are limited to what they can use as far as equipment. Turbo's are not an option for them.

But they are more efficient that a supercharger. Their tradeoff is complexity of the system, expence, and lag.

t walgamuth · #19 03-19-2006, 05:13 PM

saying that turbos are against drag racing rules?

tom w

aklim · #20 03-19-2006, 05:24 PM

Quote:

Originally Posted by imdavid28

They are limited to what they can use as far as equipment. Turbo's are not an option for them.

But they are more efficient that a supercharger. Their tradeoff is complexity of the system, expence, and lag.

The last word says it all. Lag. When you are doing 6 seconds down the strip, lag is not an option. Half a second lag could be the race lost.

t walgamuth · #21 03-19-2006, 05:29 PM

an issue when you take off after raising the rpm of the engine to whatever they use. 3000 rpm? i think that would be quite sufficient to spool the turbos.

tom w

aklim · #22 03-19-2006, 06:00 PM

With a stick shift, don't they just drop the clutch after having revved it to say 5000 rpm for a lot of those cars? I know my buddy launches at 5000 in his Mustang. That for sure won't build up the boost.

For autos, it would since you would be breaktorqing it.

As to the lag, I wonder. If you have a large turbo, it takes forever to spool up but is great for the upper range. Go to a small turbo and it works wonders for the low end but runs out of steam at the top. I think that is why the new Powerstroke engine that Ford has is running a big and little combo for turbo.

TonyD · #23 03-19-2006, 07:04 PM

The Republic P-47 Thunderbolt and the Lockheed P-38 Lightning both had turbos mounted way back in the tail. Then again, airplanes don't have the lag issues that cars do.

PanzerSD · #24 03-19-2006, 07:32 PM

that is kinda lame, I can see someone parking in a parking lot with the "turbo" steal me stickers and coming back and their turbo's gone.....
wouldn't take much to slide in on a creeper with some tools..

PanzerSD · #25 03-19-2006, 07:32 PM

Although I have seen some Power steering systems and air conditioning compressors driven off of the driveshaft...

aklim · #26 03-19-2006, 08:04 PM

I wouldn't bother with the stickers.

imdavid28 · #27 03-20-2006, 08:36 AM

Quote:

Originally Posted by t walgamuth

saying that turbos are against drag racing rules?

tom w

Yeah, I think so in top fuel and funny cars. However, in Pro stock (I think it is) most people do run turbo's.

Matt L · #28 03-20-2006, 09:47 AM

About efficiency, I put that turbo in the gasser SAAB. I used 9.2:1 pistons (stock for non-turbo) instead of 7.2:1 which were stock in the turbo. Also used the non-turbo camshaft, since this was used in the later turbo models which had knock detection.

The combination took me from 27mpg highway to 32.

imdavid28 · #29 03-20-2006, 10:34 AM

Quote:

Originally Posted by Matt L

Also used the non-turbo camshaft, since this was used in the later turbo models which had knock detection.

You may have been better off keeping the turbo cam in there. They typically will design turbo cams with minimal valve overlap so your exhaust doesn't force its way backwards in the system.

ConnClark · #30 03-20-2006, 12:36 PM

Quote:

Originally Posted by t walgamuth

superchargers as being much if any less effecient than turbo chargers.

tom w

Turbo chargers are more efficient. They capture energy just dumped out the tail pipe durring the blow down phase of the exhaust stroke. They also convert some heat to energy to drive the compressor wheel. Edit: Also backpressure is not as much of an issue on diesel as it is on a gasser.

As far as this system goes, it will be laggy as hell. However, once spooled it will help. It could be done much better though.

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