wot=wide open throttle(butterfly at intake)Quote:
Originally Posted by OldF
alternator =few more power due to less friction at alternator.
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wot=wide open throttle(butterfly at intake)Quote:
Originally Posted by OldF
alternator =few more power due to less friction at alternator.
Quote:
Originally Posted by OldF
Thank you very much for your answers!
Thanks Dimviii!Quote:
Originally Posted by dimviii
ok.... thats great when its going flat out.. we have these big things called road sections on rallys and we do use interior heaters. what happens then???
Ok, we use interior heaters on cold rallys.. there are long slow road sections...Quote:
Originally Posted by dimviii
on cold rallies we use heaters also, but water temp have to raise a little bit to make it heating.Quote:
Originally Posted by bubbaontour
in "normal" conditions we use only blower, rarely even no blower.
If you turn the pump off because the engine water is cold whats going to happen to the heater?? also how are you going to control the circulation between the rad and the heater circuit?Quote:
Originally Posted by br21
of course the pump is not stopped for minutes, or sth. just some seconds, so no such problems as above.Quote:
Originally Posted by bubbaontour
Doesnt the WRCars have electric heaters? Just wondering?
WRC I don't know, but I don't think so...Quote:
Originally Posted by Donalduck
S2000 have simple heater (which uses coolant fluid) plus simple blower.
Some modern road cars have two different cooling systems on the engine. so they can have different temperature on the cylinder head than the cylinders. They also use electric pumps controlled by the ECU (pwm signal).Quote:
Originally Posted by dimviii
which cars?Quote:
Originally Posted by Donalduck
Volkswagen,Audi and Skoda. Newest generation engines.
which engines?Quote:
Originally Posted by Donalduck
Several petrol engines in the new Golf MK7. The 1.4 122bhp engine used in the Golf MK6 have a an own cooling system for the intercooler, which is integrated in the intake manifoil.Quote:
Originally Posted by dimviii
water through intercooler at tsi 1,6 engine?Quote:
Originally Posted by Donalduck
No.Quote:
Originally Posted by dimviii
no what?
Just no!! Whats your point in these endless questions?Quote:
Originally Posted by dimviii
do you want to ask all the members if anybody have understood YOUR answers? are you scared by questions,or you pay per post?Quote:
Originally Posted by Donalduck
Yes i am scared by your questions!! i probably wont get any sleep tonight. Damn you!Quote:
Originally Posted by dimviii
so how much you pay per word?Quote:
Originally Posted by Donalduck
here everybody wants to know something he dont know or understant.If you dont bother to explain,dont waste this topic please.
I found the above a bit interesting as a mechanical engineer myself and after a bit of google search I came across this:
Dual-circuit cooling system for SSP 491 Audi 1.4l TFSI Engine With Dual Charging
(Scroll to page 31)
From what the document says it is used in 1.4l 136kW TFSI and 1.2l TFSI Engine from Audi.
thanks makinen fan!
Just a tiny point. If I'm not mistaken the 1.2 TSI engine is product of Škoda supplied to other brands of VAG.
What an interesting and informative discussion! I'll try to sum up what I found so far about the topicAll of the previously mentioned cars, namely Peugeot 207 S2000, Ford Fiesta S2000, and MINI John Cooper Works 1.6T 2000 (not sure about WRC) use electric water pumps produced by Pierburg (=KSPG), to be exact the model CWA200, which can be found in many BMWs produced since 2004 under different part numbers such as 11 51 7586925 or 11 51 7604027, depending on the motor model (M54, N52, N53, N54, N55 among others). I haven't found how sophisticated control of the pumps in rallye application is, but you can find how BMW does it here on page 75 (add the www, I can't send links yet):Quote:
...I was wondering about manufacturers switching from mechanical to electric water (coolant) pumps...
.1addicts.com/forums/attachment.php?attachmentid=586998&d=1317333814
So to me it seems like there IS a thermostat, but it's a somehow electronically controlled one plus the revolutions of the pump are controlled as well. Again, I didn't find how rallye cars do it.
Apparently there is a new model of Pierburg pumps called CWA400, which according to its name and the following plot should be about twice as powerfull: Attachment 3103. But as of now I wasn't able to find any production vehicle or motorsport car using it. Only this article mentiones several high-performance cars premiering 2013 and possibly using it (add http):
://presse-center.kspg.de/no_cache/en/press-kits/pm-single/article/sieben-top-ten-motoren-fahren-mit-kspg.html
I also wasn't able to find the relationship between Pierburg and Continental who also produce electric water pumps and call them Smart coolant pump. Sometimes I found contradictory information about which car uses which, such as here:
.conti-online.com/generator/www/com/en/continental/pressportal/themes/press_releases/3_automotive_group/powertrain/press_releases/pr_2013_01_16_best_engines_en.html
where both Pierburg and Continental claim that the new BMW 135is 3.0L uses their pump...well they are similar indeed, but can it be some sort of a cooperation? Anyway I hope this post wasn't completely uninteresting and thank you for comments.
It might be possible that BMW uses Pierburg and Continental ones for different markets. I admit I have no clue about that but I can see it as a possibility.
I want to raise a question about that dreadful understeering the Polo gets when entering corners. Where it comes from - is it a construction defect in the chassis? If yes - when they can homologate a new one? If no - which components of the transmission they can improve and which are from supplier?
understeer can create just suspension,suspension+allignment,front diff settings+suspension,or with a little help from driving style,or some combinations of themAlso you can have understeer from wrong balance between from front/rear suspension.No understeer can t be created from chassis,maybe from a wrong mounted engine(just beside the bumper like subarus) but again there are solutions to ''hide'' it,but not to reset completelyQuote:
Originally Posted by SlowSon
I think that is very hard to answer without being an insider. I'm no expert at all but in my opinion some understeering is natural for all AWD cars without central differential. If You watch closely You can see it present with all current WRC/S2000 cars (I started to notice that when first Peugeot and than Škoda found centre diff useless and stopped using it). You can play with diffs, geometry, weight balance (not much under current rules), suspension etc. but for me it remains a question what works the best with these cars. In the ideal world You prefer neutral handling but look at Loeb, he is much more understeering than most of others and he is mostly faster.
Also weight distribution and how the weight shifts under braking also has a significant role to play in this. And weight distribution is a fundamental property from the chassis, if they got it wrong initially there is no way around it but just to compensate through suspension/diff setup.Quote:
Originally Posted by dimviii
Most of the current cars are basically same in their general layout. The difference in weight balance can't be so significant like when we compare for example Impreza and Lancer or even more when we compare Quattro and 205 T16. Chassis are very similar, engines of same kind mounted in same locations, rollacages almost same, bodyshell panels are also made almost same way. What playes a more role is sure the weight shifting from suspension and geometry layout.
This is characteristic of all 4 wheel drive cars. The first Quattro which had central diff were understeering alot also. The S1 evolution was improvement by shortening the wheelbase and also taking weight in front and placing it weigth to the back like oil coolers.Quote:
Originally Posted by Mirek
The main reason why Quattro was so badly understeering was its heavy longitudinal engine in front of the front axle.
weight distribution yes,thats whu i said from a wrong mounted engine=very front mounted at subarus.Quote:
Originally Posted by makinen_fan
chassis ONLY ,can t have a wrong weight distribution,the wrong weight distribution will be if you mount at wrong places all the rest pieces.
True, anyway non 4wd car can oversteer like rwd carQuote:
Originally Posted by Mirek
to oversteer like a rwd is not correct for a 4wd,but you can have oversteer character very easy in a right designed 4wd car.Evos with some tweeks at electronic center diff,and rear alignement can oversteer quite like rwd.Quote:
Originally Posted by stefanvv
yes that's right in that chassis only cannot have any significant difference. By chassis I interpret it the chassis itself plus body, roll cage engine placing etc.Quote:
Originally Posted by dimviii
Mirek you are right that there should not be significant difference in WD, but you never know. From my work experience with F1 cars, the engineers are VERY sensitive about tiny changes in WD, not sure about rally cars though. I believe no where near, I would say that changes in +/- 2% would not make much difference. Do you or anyone know approx values for S2000 cars out of interest?
Wasn't the focus Wrc supposed to be 50/50 distribution? I thought I remember them making a big deal of that.
I am intrigued that the idea of the center differential is worthless. Being from the US and not having wrc/s2000 cars we are most familiar with subarus, and the shops that prepare subarus claim the center differential is the most important. Just wondering why the difference in philosophy?
Maybe a bit off-topic, but: BMW X-drive system starts from rear and moves to front axle when frontwheels are starting to slip. Makes the car always steering without understear. Maybe not comparable to WRC/WRC2, but I like it very much myself on wintery small road nearby my home....