Hi there

When you launching the car,does boost increase when you holding the handbrake etc.

If not then this "exercise" is waste of time and you can do serious damage,as you know properly set LC will build the boost

I've never seen such situation like you are experienced,usually if you running above boost which has been set on the ECU then you can blow the engine,ECU will try to correct the boost and try adjust the fueling

Sometimes can happen overboost,but this I've seen rarely,mostly on un mapped or non mapped cars,on mapped cars this can happen only during the cold days

I would check the pipes at least if they're not damaged and if they're not split

On first spool or in first gear usually you should have set lower boost(1bar as example or lower,depends on yours mapper)

On drag strip usually you will never see 4th or 5th gear if you are running 5speed WRX box,this box has have nice long ratio,if car is modded then 4th gear you should be changing before crossing the finish,but usually on standard WRX you will be crossing finish line in 3rd or in 4th,depends on the more factors

Thanks,Jura

 

To answer your question, Hot air is created instantly, think of a Diesel engine compressing air before spraying in diesel that ignites in this hot air, it happens very fast.
The over boost in a cold day is caused by the Intercooler being very efficient. Hope this clarifies.
Oh, I run a 16g at 1.45 bar, can't make it make more than 1.2 bar at the limiter

 

Thanks! Justifies me settling for 1.35!

So the hot air is created by the friction of the blades hitting the air at speed?

So when you hear about people running 2 BAR or more etc on other turbos what is the trick?

 

To put it simply enough, they are big and efficient enough to flow that amount of air. Try running a GT35 at 1.35bar and see what power it makes compared to your 16G

 

I run the last 50 metres or so in 4th. Think 3rd gets me to around 90-95mph. I launch at 4k because my Turbo isn't interested until 3500 (4500 before sports cat!!!) and slipping the clutch a tad means it doesn't drop to 3000 when I set off.. This technique for me knocks a whole second off my times.

TBH I've only experienced overboost once and that's when the actuator pipe came off and the wastegate stayed shut. Though I have read it would open slightly due to the manifold pressure, not sure if a map could make it stay shut via the EBC (not that that would be good policy!)

 

Won't a GT35 making 1.3 spin at the same speed of a TD05 making 1.3? Same pressure just more volume? Does the larger compressor wheel enable better heat dispersion?

 

http://www.enginelogics.com/read-a-t...ompressor-map/

 

Cheers fella.

Tout = Tin + Tin x [-1+(Pout/Pin)0.263]

I get it now!

 

I always thought there was only 1 factor why a bigger turbo made more power at the same PSI as a small turbo but there are in fact 3 or 4 factors.

So if I choose to run a larger Turbo at lower boost I'd get a safer running engine but have to put up with potential spool issues.

Has anyone ever run (for safety/or future proofing) a big ball bearing turbo at 0.8 Bar etc to get circa 320bhp or is it just an expensive exercise?