38mm Tial installed dyno chart.
03-17-2006, 09:57 AM
#32
Instructor
Hi guys, just saw this thread - interesting comparison!!!
I can understand why in theory the Tial could give different spool-up behaviour and more hp. This would be due to the design difference - the Tial valve is "backwards" so it will modify the intended slow spool-up as defined by the factory KLR-programming acting via the CV. A stock WG could also "bleed" some boost at high rpm:s, especially if the spring is weak thereby limiting boost.
Were both pulls really done with 18psi max???
If yes,how do you explain the increase in torque at mid-rpm:s ???????
Here, the WG is just regulating boost. In both cases it is regulated to 18 psi.
The WG is now completely out of the equation as far as torque goes......
18 psi is 18 psi, intake flow should be equal. I can't imagine that the exhaust backpressure is significantly different.
To me, it looks like the 2 curves have a similar shape, with the Tial curve just shifted upwards by 25 Lbs or so. (stock: peak torque 275, @6k 225, Tial: peak torque 300, @6k 250). Isn't this difference due to different Dyno:s or different boost setting or something ????
To me these 2 curves certainly don't support the statement that the Tial keeps boost better at high rpm:s since the drop from peak boost to boost @6k is comparable.....
Any expert advice out there ???
Cheers,
Tommy
I can understand why in theory the Tial could give different spool-up behaviour and more hp. This would be due to the design difference - the Tial valve is "backwards" so it will modify the intended slow spool-up as defined by the factory KLR-programming acting via the CV. A stock WG could also "bleed" some boost at high rpm:s, especially if the spring is weak thereby limiting boost.
With the guru shimmed wastegate I had setup my accuboost for 18psi, once the Tial was installed I had to turn my accuboost down because it was no longer 18psi but it was 25+psi. The old wastegate was bleeding so badly that the accuboost had to be open all the way in order to substain 18psi.
If yes,how do you explain the increase in torque at mid-rpm:s ???????
Here, the WG is just regulating boost. In both cases it is regulated to 18 psi.
The WG is now completely out of the equation as far as torque goes......
18 psi is 18 psi, intake flow should be equal. I can't imagine that the exhaust backpressure is significantly different.
To me, it looks like the 2 curves have a similar shape, with the Tial curve just shifted upwards by 25 Lbs or so. (stock: peak torque 275, @6k 225, Tial: peak torque 300, @6k 250). Isn't this difference due to different Dyno:s or different boost setting or something ????
To me these 2 curves certainly don't support the statement that the Tial keeps boost better at high rpm:s since the drop from peak boost to boost @6k is comparable.....
Any expert advice out there ???
Cheers,
Tommy
03-17-2006, 11:42 AM
#33
Nordschleife Master
Tommy you are right that a wastegate by itself will never gain power or torque. But old, worn out, wastegates tend to roll on boost and because of that midrange power is suffered.
But if you use a manuall boost controller a Tial offers no advantage compared to a stock wastegate with stiff enough spring.
But if you use a manuall boost controller a Tial offers no advantage compared to a stock wastegate with stiff enough spring.
03-17-2006, 12:51 PM
#34
How would you say the Lindsey Racing dual port WG compares to the Tial? I have the Lindsey WG but I have yet to install. I will be using it with a MBC. Your thoughts please.
03-17-2006, 02:01 PM
#35
Burning Brakes
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Gcb951
You should be fine with the Lindsey Wg With MBC. When i changed my set up to EBC i did not notice much of a difference. The only difference was with weather changers cold days to hot days. The EBC held boost rock steady all the time.AS far as spool up goes, again not much difference.
You should be fine with the Lindsey Wg With MBC. When i changed my set up to EBC i did not notice much of a difference. The only difference was with weather changers cold days to hot days. The EBC held boost rock steady all the time.AS far as spool up goes, again not much difference.
03-18-2006, 04:31 AM
#39
Instructor
This is exactly my point - there is no real difference in how the power is kept up at the end of the band. Look carefully at the torque curves :
Stock WG : Peak=275 , at 6k rpm 225
Tial WG: Peak =300, at 6k rpm 250
roll-off is practically identical.......
Stock WG : Peak=275 , at 6k rpm 225
Tial WG: Peak =300, at 6k rpm 250
roll-off is practically identical.......
03-18-2006, 07:03 AM
#40
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Quite right tommye, well spotted - the different scaling on the X and Y axes make it difficult to compare the two by eye qualitatively.
Attached are rescaled images of both dyno runs, so each has the same dimensions and shows the same area of the graph. 3000 RPM to 6000 RPM on X axis, and 50 HP to 300 HP on the Y axis. They now look a lot more similar in terms of shape, the major difference being the top one (Tial) is shifted vertically upwards.
Attached are rescaled images of both dyno runs, so each has the same dimensions and shows the same area of the graph. 3000 RPM to 6000 RPM on X axis, and 50 HP to 300 HP on the Y axis. They now look a lot more similar in terms of shape, the major difference being the top one (Tial) is shifted vertically upwards.
03-18-2006, 04:32 PM
#41
Race Car
Were both dyno's the same model? I see the charts come from different shops. Perhaps some of the difference is due to a difference in the dyno's?
I know my stock wastegate leaks something fierce. I can't even build 13psi of boost on my K26/6 anymore (it used to peak at 23+psi), with it tapering off to 5psi at redline. The exhaust only leaks at the headers, which shouldn't cost me that much boost.
I know my stock wastegate leaks something fierce. I can't even build 13psi of boost on my K26/6 anymore (it used to peak at 23+psi), with it tapering off to 5psi at redline. The exhaust only leaks at the headers, which shouldn't cost me that much boost.
03-18-2006, 04:44 PM
#42
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Interesting thread and entertaining...
It makes me wondering what I'd gain in my car ('88 951S) by going to a Tial but keeping the max boost where it is (I have to by race rules). My hope is that I might get to boost earlier and maintain it through a higher RPM range.
It makes me wondering what I'd gain in my car ('88 951S) by going to a Tial but keeping the max boost where it is (I have to by race rules). My hope is that I might get to boost earlier and maintain it through a higher RPM range.
03-18-2006, 05:59 PM
#43
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1st graph shows a 3rd and 4th gear runs both @ 18psi with a shimmed Stock wastegate
2nd graph is a 4th gear run @ 18psi with a 38mm Tial wastegate
3rd graph shows the same boost level 18psi, 4th gear run , but the following upgrades were installed: Lindsey racing super 61 T04e, SFR sgt II headers, SFR x-over, SFR down pipe, SFR test pipe.
I am planning to do a 22psi run within the next 2 weeks with a 30% Xylene mix.
2nd graph is a 4th gear run @ 18psi with a 38mm Tial wastegate
3rd graph shows the same boost level 18psi, 4th gear run , but the following upgrades were installed: Lindsey racing super 61 T04e, SFR sgt II headers, SFR x-over, SFR down pipe, SFR test pipe.
I am planning to do a 22psi run within the next 2 weeks with a 30% Xylene mix.
03-19-2006, 04:15 AM
#44
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Surely, this is not a valid comparison.
Sorry Lart, but not only are the first 2 sets of graphs from different dynos which must render the comparison worthless, the first one was also done in the summer and the second in December when the air is much colder and more dense.
btw the third one looks good but you must have also changed the chips or something as well as the other mods because you were too lean over 5000revs before but it's OK now?
Regards
Graham
Sorry Lart, but not only are the first 2 sets of graphs from different dynos which must render the comparison worthless, the first one was also done in the summer and the second in December when the air is much colder and more dense.
btw the third one looks good but you must have also changed the chips or something as well as the other mods because you were too lean over 5000revs before but it's OK now?
Regards
Graham
03-19-2006, 10:26 AM
#45
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Originally Posted by GPF
Surely, this is not a valid comparison.
Sorry Lart, but not only are the first 2 sets of graphs from different dynos which must render the comparison worthless, the first one was also done in the summer and the second in December when the air is much colder and more dense.
btw the third one looks good but you must have also changed the chips or something as well as the other mods because you were too lean over 5000revs before but it's OK now?
Regards
Graham
Sorry Lart, but not only are the first 2 sets of graphs from different dynos which must render the comparison worthless, the first one was also done in the summer and the second in December when the air is much colder and more dense.
btw the third one looks good but you must have also changed the chips or something as well as the other mods because you were too lean over 5000revs before but it's OK now?
Regards
Graham