Jump to content
SAU Community

Recommended Posts

Very simple...

Lag is the time it takes a turbo to come onto full boost; so as an example you may get full boost @ 5000rpm so your lag time is the time it takes ur car to go from 0rpm to 5000rpm

ways to fix lag;

-smaller turbo

-cams

-better flowing head

-ebc

-antilag

Link to comment
https://www.sau.com.au/forums/topic/153765-turbo-lag/#findComment-2859500
Share on other sites

ill take 2 thanks Az.
make them the big ones, and az, i need them by tonight

hahaha i feel like im in the movie.

Sadly there is no overnight parts service that does not cost less then ones left nut. :devil:

To put it simply.

Lag is the process of building up air pressure/flow mass to increase shaft speed within the turbocharger to generate positive pressure.

Until the desired boost pressure is met this is referred to as lag.

To decrease lag, smaller and lighter internals can be used within the turbocharger to increase shafts speed. (smaller turbocharger)

Lag means horsepower though :P

Link to comment
https://www.sau.com.au/forums/topic/153765-turbo-lag/#findComment-2859604
Share on other sites

turbo lag comes from the compressor not being efficient until it reaches a high speed, say 50,000+ rpm? when the compressor isnt spinning fast enough it doesn't produce much positive pressure or airflow so the engine just is burning whatever air comes in. as the compressor gets faster and faster from exhaust gas/engine load the compressor beings to "compress" the intake and stuff more air in.

when there is little exhaust gas the compressor doesnt spin fast enough, so its referred to as lag. common for the skyline range is nothing before say 2500rpm. past this theres enough exhaust gas to wind the compressor into its effiency zone and usually get around 10psi positive "boost" pressure before 3000rpm.

as engine displacment and type changes, along with turbocharger technologoy, engine tune etc so to does the engine lag. so there are a few things you can do to reduce turbocharger lag

Link to comment
https://www.sau.com.au/forums/topic/153765-turbo-lag/#findComment-2860523
Share on other sites

Turbo lag is when you order your turbo and they haven't got any and it will be a two week wait.............thats real lag.

hehe the WORST lag ever. I think we have all been thru that type of lag from time to time. :down:

I am suffering form differential mechanic lag at the moment. it is taking 2 weeks and counting to spool up... :(

Link to comment
https://www.sau.com.au/forums/topic/153765-turbo-lag/#findComment-2860801
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Updating results following our SR20det project. Data collected form improves future turbocharger making and high flowing services. So far differences between G and GT series turbine wheels, we are in the process of making a new turbine, the aim is for better mid top range flow without gain too much lag.  Result is back to back comparison of G25-660 and GTX2867 spec turbochargers on the same car, nothing changed apart from turbocharger. Both tuned to knock limit from pump 98 fuel (US Ron93). GTX2867 was about 400RPM more responsive making 255rwkws while G25-660 made 17 extra Kws with wider spread of torque after 4500RPM finishing off at 272rwkws.  
    • @GTSBoy i tried to jumper the wires and got the steering wheel light to come on which is right under the gear indication but that still doesnt come on.  Can it be an issue with my cluster?
    • Given that you have seen the dash indicator work briefly, then it would seem like you have a simple wiring problem. What happens when you simply jumper the wires on the "steering wheel switch"?
    • Yesterday's day in review: All the wiring to the lights up the front how I want it, is ran, terminated, and all to length. The only lighting up front I haven't finished is the side indicators, as I need to get to the partly cutup factory loom, and find the plugs for them. Interesting note, the side indicators use the exact same plug that's in the doors for something else that I don't remember what it is... So that plug better be careful...   Power steering solenoid, on the R33 is variable, and from memory PWM. The Ford's control from the docs I have so far, is it's just a on or off control. So I'm not sure it's what I want, and in any case, power steering running, but at its heaviest (solenoid off) is likely what I'll want anyway, so I'm not yet touching it at all. All the wiring I can complete so far, is done. There are 3 wires I need to make a plug for at the ECU, and these are just for the vehicle speed sensor, of which I need to get a T5 from an AU, so I can use its output that has the speed sensor on it. (My car doesn't have ABS, otherwise I'd set it up to use one of the ring gears on that). I need to buy new headlight globes and front parker globes, otherwise I could show photos of lights working. Current fuel lines in and out on this motor are "5/16". I'll order hardline, and some AN fittings for that, and I just need to 100% check fuel line size at the tank end, to get the ends for it. I'm also looking at a few options for the banjo bolts to AN fittings for the power steering rack. I'll pull the reservoir off the Barras PS pump. There's an off the shelf fitting for that pump for a -10 AN feed, and it'll use a 16mm to dash -6 an outlet to feed the rack. I'll be making my own power steering reservoir, I'm going through the thought process at the moment of how I'll run the baffles, and I need to research another idea for it too.
    • Two inlet runners changes the engines characteristics requiring less fuel to make torque at different points in the rev range. The smaller diameter inlet runners on the DET increases air flow speed, which improves atomisation of fuel, particularly in low load/idle for better burn, and in specific areas of the engine, (areas you would use when driving normally) increases the efficiency. All of those items change how efficient the engine is at different speeds. The changes on the neo help slightly to improve emissions where it matters. The overall improvements won't be the likes of going from an engine built in the 70s to an engine built in the 2000s, it's just a small step. But still leaves it the RB with the best chance of improvement.   As for your comment about the whole using a cat to not need to worry about those gases. Two things, no system is 100% perfect. It won't eliminate everything. So reduce the quantity you put into it, you still reduce the output. Two, make that system do less work, and it's likely to survive a little bit longer. Funnily enough to, one trick employed to get cats up to temp, AND to drastically reduce emissions before they get up to temp, is to reduce ignition timing.
×
×
  • Create New...