129bhp from a 1.9td

rossd · Post by **rossd** » 01 Feb 2005, 16:56

The 90bhp HDi doesnt have an intercooler, hence the high charge temps!
If you are interested, take a look here for the theory and formulas:
http://www.gnttype.org/techarea/turbo/turboflow.html
And here for the turbo maps:
http://not2fast.wryday.com/turbo/maps/GT15compress.jpg

Kowalski · Post by **Kowalski** » 01 Feb 2005, 17:07

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by mrbump

About the torque thing, did anyone see Top Git that time when clarkson got beat in the 400bhp evo by some sub 100bhp trolley in fifth?, no torque at all due to low comp and massive lag. Just shows ya, catch them sleeping in the diesel, and boost past before they get a chance to shift![}:)][}:)][:D]
<hr height="1" noshade id="quote"></blockquote id="quote">
Actually, with the diesel in traffic, when you're in a queue and the queue sets off, I'm often left behind.
If I'm above my torque band there is a short burst of power followed by a gearchange, the turbo doesn't have time to spin up so there is the usual post gearchange lag. If I'm below my torque band, I get big lag.
I'm convinced that in traffic, a petrol would require less gear changes than my diesel, when a queue varies up and down in speed the diesel needs numerous gear changes to keep it anywhere close to its torque band where as a petrol has a flat torque curve. The HDIs are probably better since they produce more torque lower down and have less turbo lag.

mrbump · Post by **mrbump** » 01 Feb 2005, 17:14

K, very true. Mine is also a pain in very slow traffic. They come into their own at around 40-60 and can accellerate faster in the higher gears than most 2.0 litre petrols up to about 90 in my experience. The problem is that 1st gear is so bloody short. I reckon you should give it more revs and slip the clutch a bit more, or short shift and get into the power in second. Dont bother revving it out in first.
No intercooler on 90 hdi --- why?[:0]
even my bro's 1.3 td corsa has one. Is it a low blow turbo then? Very small gt15? be careful with the boost there then!!![:0]

rossd · Post by **rossd** » 01 Feb 2005, 17:22

The GT15 is the equivelent to the older T2 turbo as used on the XUD turbos. I'm not sure why it hasnt got an intercooler, probably to keep costs down. It would certainly increase the efficiency of an already efficient engine! As standard it runs 0.95 bar boost, again about the same as the old XUD.

arry_b · Post by **arry_b** » 01 Feb 2005, 17:32

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by paranoid

In the words of the old fella who taught me how to tune 2 strokes.....
They can all make staggering BHP.......long pause.......FOR A VERY VERY SHORT WHILE[:D]
<hr height="1" noshade id="quote"></blockquote id="quote">
Ahh, so THAT'S why my bikes last a long time [;)]

DaveC · Post by **DaveC** » 01 Feb 2005, 20:17

I just re-tuned my fuelling this weekend after a cambelt and major service (180,000 miles)...
I own a 405 Tdi, L reg, and my brother has a similar model (Mi16 cross with a 405 Tdi, and a Xantia Tdi engine)...
We've tried all kinds of fiddling and tweaking the pumps and the nature of the engine can be seriously altered with just the fuel pump.
In our experience, we can never get any more than 1.1 bar from the turbo no matter how hard we tune the pump up. My brothers manages 1.2 bar (guessed the wategate actuator arm length as the Xantia turbo is slightly different, turbo outlet points in different direction)...
However, testing mine right after major service, 1 bar at 2000rpm, 1.1 at 3000rpm, 0.8 ish at 4000rpm.
Brothers car, 0.7 bar at 2000rpm, 1 bar at 3000rpm, 1 bar at 4000rpm.
Now, both cars clearly have 1-1.1 ish bar max, but the FUELLING slope is key to the delivery.
Mine is setup for a big lump of torque early on, yet my brothers doesn't even feel like it kicks really like mine, but it really revs hard after 3000rpm.
Adding top end fuelling clearly gets you top end boost, lots of low-down fuelling gets good turbo spool up and low-end boost.
I can safely say there is NO way you'd get 1.6 bar without HUGE fuelling at the top end to actually supply that kind of output from the compressor end of the turbo.
After my major service and some tweaking, I got my fuelling lots better. I've adjusted the Bosch pump max fuelling, and altered the slope by rotating the compensator shaft a bit, and also removed the compensator washer and rasied the spring seat too.
I've pretty much lost the original settings, but each time I mess about, I get more clues as to how they are working.
Right now, I've got the fuelling with a moderate push at 2000rpm, but cut back the low-end fuelling for less smoke on wide throttle low-load. I manage a good 1 bar from 2200rpm through to 3500rpm, but I really want to tweak the fuelling curve now to really get a nice push at 2500rpm, and keep it there till 4000rpm...
Just so many adjustments, and the more you thrash test the car, the hotter the intercoolers getting, and so the more smokey it *can* get when normally it'd be fine...
Wonder if I should just let Allard or similar loose on it, if it'd really be done that much better!?
Dave

mrbump · Post by **mrbump** » 01 Feb 2005, 21:15

I have to say, I have had 23 psi out of my KKK turbo on the guage. Thats 1.56 bar. I beleive that the Garret versions wont push that much due to the differences in wastegate, the 'door' or that design gets blown open as the boost presssure exceeds the force applied by the spring in the actuator to keep it closed.
Also my turbo has zero backpressure to fight. Basically, at the moment, I have the actautor on the kkk set at almost max, and can adust max boost as a function of fuel just using the full power fuel screw. I can vary it from 15 to 20 psi. I have standard setting on the boost adjustment fuelling. The turbo will hold 20psi to 4000rpm.
I reckon that if you used a 'dawes device' between the compressor and actuator on the t2 you could see more boost, but as soon as it opened, you would loose it again. A better idea would be to use an actuator like a -31 from a cossie or something that could tolerate holding higher pressures.

rossd · Post by **rossd** » 01 Feb 2005, 21:24

When I had my old 306 Dturbo, I did the same as you DaveC, continually adjusted the fuel pump. I could get well over 20psi if I needed to at 4000rpm, but there was no need for that much boost I felt. I good compromise was reached with 1 bar at 2200rpm, as you have described. Still did 46mpg too!! The pull was fantastic, once you were on boost it would steam away from almost anything. My new HDi seems like a real slug in comparison, but its much easier to drive, with torque all the way from 800rpm!

sooty · Post by **sooty** » 02 Feb 2005, 01:39

OK I've read all the comments, but has anyone experienced that sort of boost without busting the intercooler or head gasket.??

VLL · Post by **VLL** » 02 Feb 2005, 02:53

Mines currently running at 1.6bar max boost with the KKK turbo, will get someone to take a photo of the guage to prove it next time i'm out.
Its been at 1.6bar for nearly a year now with no problems.

mrbump · Post by **mrbump** » 02 Feb 2005, 15:20

Hi VLL,
What kind of mileage was on the engine before you tuned it? How often do you use max boost? Any other modifications? Would it be at all possible for you to take some readings of the intake temps please?
Cheers

VLL · Post by **VLL** » 02 Feb 2005, 21:55

The mileage was about 90,000 when the boost was increased, its on 102,000now
As for how often I use max boost, since I live in a quiet part of the country with zero speed cameras for miles and a low police presence and that I have a lead foot I would say it spends most of its time on boost. At least twice a month it does a late night sprint of 36miles where it spends most of its time in 3rd and 4th gear and the revs never drop below 3000!!!
I have often wondered about intake temps as I know once you start getting up over 20psi temps rise quickly but have no way of measuring them. I have no issues with reliability so far so can only assume 1.6bar is within the capabilities of the engine.

BonceChops · Post by **BonceChops** » 02 Feb 2005, 22:31

What sort of inlet temp would you expect to see on a 'normal' engine. What would be the max temp before the air density started to make the extra boost useless

tomsheppard · Post by **tomsheppard** » 03 Feb 2005, 01:51

As the 1.7 gives 90 BHP, 129 from the 1.9 doesn't actually sound like a huge increase. The 1.9 n/a gives 71 so I guess that the 1.7 n/a gives 65, the turbo adding c. 35%. The 1.9 turbo probably does about 105 and an extra 25 bhp should be within its compass. I'd be increasing fuelling rather than necessarily boost and using a larger intercooler. Bigger exhaust diameter will help, too. But it will go bang eventually. They all do.

stubbsy · Post by **stubbsy** » 03 Feb 2005, 02:49

excuse my inexperience but are you sayin that by tweeking the pump settings that this also increases boost? i was under the impression that adjusting the waste gate arm "upped" boost.im currently trying all this but have no boost guage?is this wise?