Turbo upgrade time
Posted: Wed Jun 03, 2015 4:53 am
I've just been to the turbo shop and ordered my first hybrid turbo- a TD04 49177-01510 with a 13G compressor instead of the stock 09B compressor wheel. So excited! Also, probably not going to explode like my current one is!
Basically, I've finally got the van running the way I like it with a bit of extra boost and the fuelling nicely sorted, and decided to plot my current boost range onto the stock turbo's compressor map.
Not sure how familiar you are with compressor maps- the vertical axis is boost (2.2 equates to about 15psi on our vans, 1.4 is about 5psi), the horizontal axis is airflow (which goes up as the engines RPMs go up) but the important bits are the whorls in the middle (where the compressor's most efficient), and the right side boundary (beyond which the turbo is working beyond its specifications).
The pale red area I've added is the range of boost and airflow that my engine is capable of. The red dots are points that I was particularly interested in- from left to right they are: 1500rpm taking off from a stop, 2500rpm motorway cruise, 3000rpm powering uphill, 4000rpm power peak. From the way the red area hangs off the right side of the turbo's map you can tell that almost everything my turbo does is outside of the turbo's efficiency zone, and a lot is into the over-worked explodey turbo badlands. Not good.
Here's the same range on a 13G turbo:
That's more like it. I might have lost a bit of boost around 1500rpm, but Highway cruise happens right where the compressor is most efficient, 3000rpm pulling uphill is still plenty efficient, and even at maximum revs and full boost the compressor is not being over worked.
Just for a laugh, I tried the same thing with a 15G compressor:
Well, the turbo's not going to blow up, but it's hardly going to do any work at all either. I'll stick to the 13G compressor, I think.
The turbo shop reckons it'll be ready early next week. I'll keep you updated...
Basically, I've finally got the van running the way I like it with a bit of extra boost and the fuelling nicely sorted, and decided to plot my current boost range onto the stock turbo's compressor map.
Not sure how familiar you are with compressor maps- the vertical axis is boost (2.2 equates to about 15psi on our vans, 1.4 is about 5psi), the horizontal axis is airflow (which goes up as the engines RPMs go up) but the important bits are the whorls in the middle (where the compressor's most efficient), and the right side boundary (beyond which the turbo is working beyond its specifications).
The pale red area I've added is the range of boost and airflow that my engine is capable of. The red dots are points that I was particularly interested in- from left to right they are: 1500rpm taking off from a stop, 2500rpm motorway cruise, 3000rpm powering uphill, 4000rpm power peak. From the way the red area hangs off the right side of the turbo's map you can tell that almost everything my turbo does is outside of the turbo's efficiency zone, and a lot is into the over-worked explodey turbo badlands. Not good.
Here's the same range on a 13G turbo:
That's more like it. I might have lost a bit of boost around 1500rpm, but Highway cruise happens right where the compressor is most efficient, 3000rpm pulling uphill is still plenty efficient, and even at maximum revs and full boost the compressor is not being over worked.
Just for a laugh, I tried the same thing with a 15G compressor:
Well, the turbo's not going to blow up, but it's hardly going to do any work at all either. I'll stick to the 13G compressor, I think.
The turbo shop reckons it'll be ready early next week. I'll keep you updated...