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Lag... :(


grahamc
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Ok... Probably a silly question...

 

But what are the ways of getting around lag on say a large single turbo'd supra?

 

I know that rally cars use a form of anti-lag (ECU based) that keeps the turbo spooling, but destroys the life of the turbo.

 

Someone I used to know that put a much large than usual turbo on subaru impreza used ECU controlled NOS as an anti-lag (well sort of). Was great in the beginning, but the engine didnt last very long.

 

So what are the options for a supra?

 

:search:

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Obviously would be my choice, but if there is a solution, I want to consider it.

 

I have had a T88 on a skyline and the lag was dreadful, massive power when it came in but not much fun to drive in town, I swopped for a HKS TO4Z and this was an awesome turbo, the supra at Weston Performance and another I saw at TDi had progressive NOs and this was shut off when the turbo was up to full spool but got it there much quicker

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Options are limited really. Obviously the more expensive route is to actualy give yourself and overall power goal. then try and choose a Turbo which can be pushed to that powergoal when needed but will provide power easily below your goals. Say you want for talk sake a goal of 750bhp. Something like a gt40r which has quite good spooling characteristics and will provide usuable power 450-600hp but when needed can be pushed to the 750hp mark. Im not recommending a turbo, as there are so many to go with.

 

Depending on the type of turbo, simply swapping out the hotside for a smaller one if availble is usally the quickest and easiest route, but your limiting your overall power goal. Say going from a large 1.04AR down to a 96AR.

 

the other option as said would be a progressive NOS controller.

 

A really good fuel/ignition map can help aswell, with very agressive ignition values below the lag range to enable to the engine to get up there quickly.

 

Hi-stall converters on Autos, or 2 step limiters/launch control can also aid spooling but in a point to point race environment i.e. away from the lights or up a drag strip.

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Guest Terry S

Depending on the type of turbo, simply swapping out the hotside for a smaller one if availble is usally the quickest and easiest route, but your limiting your overall power goal. Say going from a large 1.04AR down to a 96AR.

 

 

 

remebering that if you reduce the exhaust housing size too much you can induce massive compressor surge.

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In a word "MAPPING".

 

There is a world of difference between a well setup map on a single and a rubbish one...

 

But some turbo's are too big for the application.

 

T61-T67 Street

T71+ getting silly :)

 

At the end of the day, I will more than likely go for something the T61/67. Just trying to figure out what options there are.

 

And obviously the application of the car, will make a world of difference, IE. street vs drag vs track, etc.

 

Car would be manual... :D

 

Nice idea bondango!

 

How much of a difference does a DBB turbo make? Or is it very minor?

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Depends what you mean by lag too. The lag that rally-style anti-lag systems get rid of is where the turbo slows down and drops off boost between gear changes. Then there's the delay you get before the turbo gets enough exhaust gas to spool up from low revs, which is a different thing. Anti-lag isn't going to stop that.

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A few people seem to be suggesting using nos to get around the lag issue... but do these people realise that you really didn't ought to be using nos at low rev ranges? Should be only on WOT and mid-high rev ranges only.

 

I only mentioned it as I have seen it at Weston and TDi and they promote it as an option to lag, never driven a car with this set up though

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Lag is overrated imo... you can always change gear:)

Come for a spin in mine in a few weeks when its all run in.. Lag will be the last thing on your mind:D

 

I do agree a bit here, when I was running a T88 the suspense of waiting for the power to surge in made the lag a real crowd pleaser at times! ;) , Jamie I am sure your car have much more to discuss that lag when finished

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Guest Terry S
The T67 does sound to be a great street turbo.. probs your best bet.. any bigger turbo and your looking at a built engine imo as it wont last long if run to its full potential:)

All imo of course:)

 

Jeez you've changed your tune Jamie LOL

 

Lag is a royal PITA for a fast road car. You will not notice it on dualies or Motorways becuase then you can change gear, but around the twisties it is infuriating. I have had a 74GTS & mega quick spooling GT35R hybrid, and the later was sooo much more fun to drive.

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