Turbos and drag racing

When youre racing dont turbos take a while to kick in?
Arent they useless for drag racing?

Yes, you do get turbo lag. It does take time for the exhaust gasses to spool the turbo. However, there are small turbos that take almost no time to spool. Also, the bigger engine you have, the more airflow you have, the eaiser and quicker the turbo will spool.

So no, turbos aren't useless for drag racing.

Turbos will beat the supercharged engines if they were allowed in the faster classes.

i love the term "turbo lag" most of the people that say it dont know what it is. if you properly set up a turbo and get the right size you wont hardly notice any lag. besides who starts a drag race from idle?

Turbos don't create boost in neutral, they are load dependant.

line locks are great

Turbos don't create boost in neutral, they are load dependant.

:rofl: :rofl: :rofl: ya you obviously havent driven many turbo cars...you go out to any turbo car...put it in neutral then rev it to reline then snap the throttle shut....the BOV is going to let out a nice squeak and if you look at the boost guage it will rise as soon as the turbo spools which for a good car with a proper turbo for that engine will happen between 2000-3000RPM the boost guage will begin to rise untill your wastegate opens to regulate boost....and if you are drag racing or anytype racing for that matter and starting at idle then you are pretty stupid...you dont want to launch from redline but you also odnt want to launch from idle...if you have proper tracking holding the RPMs just above where you are suspecint your car is makeing its peak torque is the best place to launch from...in a manual transmission once you are staged put it in neutral and heel toe to bring the revs up while ensureing that your car stays put. then once the other car is stages put it in whatever gear you want to start in...if you have a problem with sipning the tires then i reccomend getting better tired or launching in 2nd...hold hte clutch in and as soon as that green light ligts up dont dump the clutch but do let it out pretty quckly...then just up shift as you reach your redline...in an auto you can brake and hold the revs ...but hten agian i dont like drag racing because any moron with a month of driving experence can up shift quickly...it takes skill to turn corners...and no NASCAR doesnt count since its all left hand turns over and over....

Turbochargers are load dependant, they need load to give boost unless you have an anti-lag system.

Turbochargers are load dependant, they need load to give boost unless you have an anti-lag system.


Not to long ago I was reading an interesting discussion on this topic over at:

http://www.eng-tips.com/viewthread.cfm?qid=99579

The thread also goes into the importance of the exhaust gas temperature which was in question in the "Remote Turbo" thread.

I'm not very inclined in the Physics department, so I don't quite understand what load has to do with amount/temperature of the exhaust gas going into the turbo. I tried reading through the link in the above post, but it made my head hurt. SaabJohan, can you explain in Layman's terms?

I'm not very inclined in the Physics department, so I don't quite understand what load has to do with amount/temperature of the exhaust gas going into the turbo. I tried reading through the link in the above post, but it made my head hurt. SaabJohan, can you explain in Layman's terms?
With a gasoline engine at part throttle the throttle limits the airflow into the engine and add fuel in relation to the airmass. This results in a low exhaust flow and lower temperature.
Since more air equals more fuel which give more exhaust energy the boost is instable, it will increase until the turbine can't deliver the power needed by the compressor.

With a diesel engine the airflow doesn't depend on the load as there is no throttle. Fuel is added dependning on load which increase the temperature under load and exhaust flow a little bit becuase of the fuel. Since fuel isn't added in relation to airflow the boost will become stable.

Exhaust flow = air flow + fuel flow

:rofl: :rofl: :rofl: ya you obviously havent driven many turbo cars...you go out to any turbo car...put it in neutral then rev it to reline then snap the throttle shut....the BOV is going to let out a nice squeak and if you look at the boost guage it will rise as soon as the turbo spools which for a good car with a proper turbo for that engine will happen between 2000-3000RPM the boost guage will begin to rise untill your wastegate opens to regulate boost....and if you are drag racing or anytype racing for that matter and starting at idle then you are pretty stupid...you dont want to launch from redline but you also odnt want to launch from idle...if you have proper tracking holding the RPMs just above where you are suspecint your car is makeing its peak torque is the best place to launch from...in a manual transmission once you are staged put it in neutral and heel toe to bring the revs up while ensureing that your car stays put. then once the other car is stages put it in whatever gear you want to start in...if you have a problem with sipning the tires then i reccomend getting better tired or launching in 2nd...hold hte clutch in and as soon as that green light ligts up dont dump the clutch but do let it out pretty quckly...then just up shift as you reach your redline...in an auto you can brake and hold the revs ...but hten agian i dont like drag racing because any moron with a month of driving experence can up shift quickly...it takes skill to turn corners...and no NASCAR doesnt count since its all left hand turns over and over....
Nah, as a matter of fact, I have driven NO turbo'd cars.

I understand that an automatic transmission linked with a turbo will pretty much take out all the lag of a turbo because of the ability to break boost at launch and the advantage of not needing to let off the gas.

Of course any moron can shift up quickly, but it I think it still takes a bit of skill to shift up 0.01 second faster than the guy beside you.

Well even though Nascar is all left hand corners, they are high speed corners, and the fact that they are banked at different degrees making every turn quite different from the others, I personally don't like Nascar, and just because it's as boring as watching grass grow does not change the fact that it DOES indeed take skill, otherwise the American public is wasting their money on something that anybody can do, like paying to watch someone run around in a circle.

>>like paying to watch someone run around in a circle.<<

it is like paying to watch some one run...well drive... in circles...