Dumb Q #1: Benefits of Larger Turbo

[Dan3SGTE]

reading your last post GTti im sure your saying we were right?

Twice the size nozzle will allow more fuel to go through at the same pressure... i.e air in our case.....

But on the other hand wouldnt the pressure increase if there was a larger volume? therefore you would be running higher boost....?

 

[Gee]

Do bigger turbo's compress more air than smaller turbo's?

If so, that would explain why they are capable of pushing more air down the same 'pipe' at the same PSI?

 

[Dan3SGTE]

that would explain exactly why, you would compress the air to a smaller capacity but in theory there is more air and the pressure hasnt increased....

But to compress more im sure would only determine by the actual design of the blades not the size of the blades....

 

[Adam_Glanza]

tbh fuck knows im not a scientist, but liquids and air are two different elements.

but basically weve established that a bigger turbo WILL push more air than a smaller turbo @ the same psi.

now where does that extra air go? nowhere it goes into the pipe. it doesnt disappear it just gets compressed, even if its the same piping it just squeezes up.

 

[Dan3SGTE]

but adam, if it squeezes up that would cause an increase in pressure.... thats my only concern to this..

 

[Adam_Glanza]

would it?

well to be honest like i said i dont know the ins and outs but im pretty sure were right.

unless he can explain it

 

[59bhp]

gtti is right however much it pains me to admit.

9psi is 9psi no matter how it arrives at that pressure. Its a result of the air pump (turbo) if its smaller it will just have to work harder to achieve that pressure, if its larger it will have to do less work to achieve 9psi.

Excuse the awfull analagy but if an engine is making 80KW of power when the engine is doing 2000rpm its the same power output as an engine making 80KW of power at 8000rpm. You still arrive at the same output irrespective of the means.

 

[Guye]

I've always related turbo sizes and output to industrial air compressors we sell. I have seen that with air compressors you can have many different units all rated @ 90psi output. What you want to check is the cfm rating of the compressor's airflow. Using the same 1/4" IM fittings you can get the same 90psi (pressure) but varing cfm (cubit feet per minute) of airflow. The outlet space is the same, the pressure is identical, but the amount of air being moved varies.
That is industrial compressors, but I always believed the principle was the same for for turbos. You can get the same output pressure on two different sized turbos, but the airflow must be different. (gone to get proof...)

 

[Dan3SGTE]

i still think what i think in this one until im actually proved.... there is more air at the same pressure...

The results are too big of a gain at the same pressure on most bigger turbos for it to be just a cooler charge...... has got to be more air entering the engine....

 

[Guye]

Found nothing but factory ratings on air compressors...surely the principles involved must be similar? I always figured hybrid ct9 flows more air than stock, and td04's flows more than hybrids, that's why you get leaner afr's with the same psi with each upgrade. There must be more air being induced into the cylinders therefore more fuel is needed to compensate I always figured...it would explain why it's safe to run 15psi on a stock engine with a ct9 (fueling adjusted of course), but your stock engine will go boom if you run 15psi on a td05 no matter how you are fueled. Same pressure, greater airflow.

 

[Adam_Glanza]

59hp we were never saying that the td04 produces more pressure?

pressure and volume are two different things.

you can have more volume while maintaning same pressures.

 

[GTti]

At 15psi the CT9 compressor is transfering alot of energy(heat) to the intake charge because it's working alot harder. A TD04 compressor at 15psi is producing the same pressure more efficienctly, less heat, more density.

At 9psi the CT9 is happy, it's efficient, as is a TD04.

At 9psi the difference is going to be un-noticeable, hence the reason for me stating that you will gain minimal or no extra power. The extra power you're talking about is coming from manifolds and decat pipes to suit the TD04 which is changing the volumetric efficiency of the engine beyond a range that the ECU has variables for.

 

[Dan3SGTE]

ok so what about both turbos well within their efficinecy range such as both on 13-14PSI.... the TD04 will make a fair amount more power at 1bar then a CT9 would.. a good 20-30bhp more..... and the TD04 isnt big at all really.. its still a small turbo to be fair..... What about a TD05 @1BAR compared to a CT9 @1bar both in their efficiency range and both with mods to suit to the turbos....

not even a comparison..... expalin that?

 

[GTti]

pressure and volume are two different things.

Volume has absolutely nothing to do with this thread btw

The volume is the area which you can put something in, it has nothing to do with air.

 

[GTti]

ok so what about both turbos well within their efficinecy range such as both on 13-14PSI.... the TD04 will make a fair amount more power at 1bar then a CT9 would.. a good 20-30bhp more..... and the TD04 isnt big at all really.. its still a small turbo to be fair..... What about a TD05 @1BAR compared to a CT9 @1bar both in their efficiency range and both with mods to suit to the turbos....

not even a comparison..... expalin that?

What forum have you been on for the last five years?

A CT9 at 15psi is well well into the limit of a CT9's efficiency range. Absolute limit!

 

[Gee]

At 15psi the CT9 compressor is transfering alot of energy(heat) to the intake charge because it's working alot harder. A TD04 compressor at 15psi is producing the same pressure more efficienctly, less heat, more density.

At 9psi the CT9 is happy, it's efficient, as is a TD04.

At 9psi the difference is going to be un-noticeable, hence the reason for me stating that you will gain minimal or no extra power. The extra power you're talking about is coming from manifolds and decat pipes to suit the TD04 which is changing the volumetric efficiency of the engine beyond a range that the ECU has variables for.

So...if a TD04L was used with the same stock manifold and everything else as the CT9 there will be NO gain at all?

You say there might be MINIMAL gain. How would this occur then?

 

[Dave@TM-developments.com]

Benefits of Larger Turbo
Quite simple really. More air + more fuel = bigger bang = more power. Thats your answer to the original question

 

[GTti]

So...if a TD04L was used with the same stock manifold and everything else as the CT9 there will be NO gain at all?

You say there might be MINIMAL gain. How would this occur then?

Yes, minimal because it may be more efficient as compressing generates heat.

 

[Adam_Glanza]

Benefits of Larger Turbo
Quite simple really. More air + more fuel = bigger bang = more power. Thats your answer to the original question

exactly. thats the point im making?

but your stating that the extra air is only down to the turbo not generating as much heat?

and how can you say volume has nothing to do with it? the extra volume of air coming from the bigger turbo makes the difference, not the amazing difference of temperature.

even if u ran the ct9 @ .6 bar and a hybrid at .6 it would still make more

 

[Gee]

Yes, minimal because it may be more efficient as compressing generates heat.

But has both turbo's are happy at that boost, will the CT9 still produce more heat?