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Old 20th May 2009, 18:03   #166
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Thanks for dropping in Jitu, i dont think anyone has info on stock readings. Could you let us know from your experience with turbo's, at what rpm's max boost is made and is it corresponding to max torque or bhp rpms? atleast any theories.

Another deduction am making, boost is more at higher gears since there is a ram effect of air from cai/snorkel and/or spooling from earlier revs?

Revs especially since holding rpm close to 2000 and accelerating will give better rush.
There are lot of factors which has to be considered & its not like 1 rule for all like xx rpm you should get xx amount of boost. Some of the factors which will influence boost are

1) Engine C.C Bore/Stroke, eg on 2L motor if i put a smaller turbo say T25 The boost will come very quick as volume of exhaust gasses is high & you will see peak boost at lower RPM, but as you increase revs the volume of exhaust gasses will surpass the limit of tiny T25 turbo. but you get max CFM from that Turbo at lower RPM & when you increase RPM/Boost the Turbo goes out of its efficiency range.

2) Design of intake & exhaust manifold, down pipe
A properly design exhaust manifold & down pipe is very crucial for Turbo setup, any restriction in exhaust, improper design manifold , improper size of exhaust Piping & down pipe will hurt power as it will increase the back pressure.

3) Turbo size & Trim
Now with a big turbo & smaller engine it will take a lot of time to spool the turbo as the tiny eg 1.5L engine will not have enough exhaust volume at lower rPM to spool the turbo, so it has to revved high to have enough exhaust volume to spool the turbo.

All turbos have a powerband & depending where you want your powerband you can select appropriate turbo for your engine you plan to turbo. On a proper sized turbo/engine a smaller Trim eg .50 in Hot side will spool a turbo quicker.

4) Camshaft also play a vital role in making power, but this subject is something very deep & you have to be very clear in Camshaft Terminology & how it effects the air flow in forced induction setup. Most aftermarket Cams needs to be "Degree in" on an engine to get optimum power which i don't think most of the people do here.

Last edited by Ford Rocam : 20th May 2009 at 18:04.
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Old 20th May 2009, 20:44   #167
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Thank you very much Jitu, your post has indeed cleared many of my doubts!

The exhaust plumbing is really good in this car, though i have to do some more research on the intake side. Regarding the turbo i faintly remembering k mark someplace long time back. Planning to do some more peeking inside over the weekend.
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Old 20th May 2009, 22:14   #168
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Jitu, then what could be the reason of the turbo spooling later at 2200 rpm in the later part of the cars life and initial part at 2000 rpm ? has everyone baffled by this change of charactersitcs!

If you could shed some light on this please!
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Old 21st May 2009, 00:01   #169
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Jitu, then what could be the reason of the turbo spooling later at 2200 rpm in the later part of the cars life and initial part at 2000 rpm ? has everyone baffled by this change of charactersitcs!

If you could shed some light on this please!
I didnt get your question? you mean to say difference in car response when it was new & now old. If thats what you meant then probably it could be due to clogged air flow. You should see the turbo & air filter when its new & after 1 year of running you should see the turbo by removing compressor cover & Turbine outlet, you will notice amount of dust/smug accumulated typically black color, try cleaning that with a new air filter & see the response. also check your exhaust system for restriction.

I do this once in a year on my own turbo given that we drive in indian weather condition with plenty of dust around,it helps maintain same performance level & not to forget Oil lines going to turbo it should not be clogged. You can check that by removing oil line going to turbo & just direct the outlet to inside of tappet cover (oil cap) so if oil comes, it goes directly back to engine, if oil level is less due to clogged oil line going to turbo then the turbo does not get required enough lubrication & due to excessive heat the bearings inside the turbo starts to deteriorate there by reducing the air flow & loss in power and ultimately turbo failure.

Last edited by Ford Rocam : 21st May 2009 at 00:13.
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Old 21st May 2009, 00:44   #170
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Originally Posted by Ford Rocam View Post
I didnt get your question? you mean to say difference in car response when it was new & now old. If thats what you meant then probably it could be due to clogged air flow. You should see the turbo & air filter when its new & after 1 year of running you should see the turbo by removing compressor cover & Turbine outlet, you will notice amount of dust/smug accumulated typically black color, try cleaning that with a new air filter & see the response. also check your exhaust system for restriction.

I do this once in a year on my own turbo given that we drive in indian weather condition with plenty of dust around,it helps maintain same performance level & not to forget Oil lines going to turbo it should not be clogged. You can check that by removing oil line going to turbo & just direct the outlet to inside of tappet cover (oil cap) so if oil comes, it goes directly back to engine, if oil level is less due to clogged oil line going to turbo then the turbo does not get required enough lubrication & due to excessive heat the bearings inside the turbo starts to deteriorate there by reducing the air flow & loss in power and ultimately turbo failure.
Thanks Jitu for that, really really informative. Everyone Turbo here has started spooling from the earlier 2000 rpm to 2200 rpm!
Mine started after 5 thousand km service and say 2 months of the cars ownership. The turbo spools late only in 2nd gear, at 2150 rpm. In Rest of all gears, say 3rd, 4th and 5th, it spools exactly at 2000 rpm and the tension starts at 1900 rpm. What could be the reason for this too ?Isnt it supposed to spool in each gear at 2150 like in 2nd gear it does? Isnt it too early for the turbo to get clogged in these many kilometers of the engines life and running?
I clean the air filter every 1500 to 2000 km and yes its clogged then!
Should i ask the Mass to open the compressor and clean it ?

Strange everything works in this ddis engine i must say!!

Last edited by humyum : 21st May 2009 at 00:46.
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Old 21st May 2009, 21:42   #171
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humyum dont do anything please, if you really want some investigation stick to the scanner reading of boost pressure.
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Old 22nd May 2009, 23:04   #172
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Hey ripper,

Wanted to ask you this, what is the delay that you are facing in getting a replacement? Is it still pending approval from MUL or is it part awaited?
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Old 23rd May 2009, 13:08   #173
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Jaggu,i think its part awaited,Probably by month end it would be replaced.
ram
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Old 24th May 2009, 00:13   #174
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Thanks r_h, ripper please take the before and after readings and post.
thanks.
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Old 31st May 2009, 08:15   #175
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Been awfully busy, and the net connection was down. hence my long absence from this thread. Any other owners with updates?
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Old 31st May 2009, 09:38   #176
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Driving around Kerala in the rain and she is running beutiful. Oil has made tremendous difference, engine purs like a petrol especially once it runs around 100 kms and I thought my clutch was toast

Maruti if you are listening, pile on your dealers and ensure they use Mobil Delvac.
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Old 9th June 2009, 06:04   #177
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Just had a thought! The Tech2 showing no error codes just means all the sensors are working properly. and that the readings they are providing are reliable. whether those readings are appropriate for the particular car in question at that particular rev range is to be confirmed by the user of the scanner, not the scanner itself.

So, if you want the tech 2 to be used properly, the readings will have to be compared between a normal and supposedly defective car.
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Old 9th June 2009, 06:23   #178
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The turbo spools late only in 2nd gear, at 2150 rpm. In Rest of all gears, say 3rd, 4th and 5th, it spools exactly at 2000 rpm and the tension starts at 1900 rpm. What could be the reason for this too ?Isnt it supposed to spool in each gear at 2150 like in 2nd gear it does?
The simple reason for this is that the turbo will spool up only after a certain volume of air has passed through it. In 2nd gear, the revs rise rather quickly, and by the time the car gets to over 2000rpm, not enough air has actually passed through the turbo to spin it up completely.

In the higher gears, the time is sufficient so that the turbo spools up properly.

Hope this clears your doubt.
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Old 29th June 2009, 13:03   #179
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I didnt get your question? you mean to say difference in car response when it was new & now old. If thats what you meant then probably it could be due to clogged air flow. You should see the turbo & air filter when its new & after 1 year of running you should see the turbo by removing compressor cover & Turbine outlet, you will notice amount of dust/smug accumulated typically black color, try cleaning that with a new air filter & see the response. also check your exhaust system for restriction.

I do this once in a year on my own turbo given that we drive in indian weather condition with plenty of dust around,it helps maintain same performance level & not to forget Oil lines going to turbo it should not be clogged. You can check that by removing oil line going to turbo & just direct the outlet to inside of tappet cover (oil cap) so if oil comes, it goes directly back to engine, if oil level is less due to clogged oil line going to turbo then the turbo does not get required enough lubrication & due to excessive heat the bearings inside the turbo starts to deteriorate there by reducing the air flow & loss in power and ultimately turbo failure.

Hi,
This exactly is the issue in my scorpio 2.6 crde, i feel it is not optimal.I don not feel the surge. Pls advice.

tnx

Last edited by PRADEEP KUMAR : 29th June 2009 at 13:05. Reason: wrong quote
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Old 29th June 2009, 13:15   #180
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my ddis had not been feeling the same way since a long time now. the turbo used to spool at around 2500rpm. also my engine used to die randomly on pressing the clutch. showed my car at my workshop and i dont know what did they do but she feels eager to run now. acceleration both pre and post 2000rpm has improved. turbo kicks in at exactly 2k mark.
will ask them what did they do and update you guys at the earliest.
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