Compression ratio 11.3 only required 87 octane ???
#1
Instructor
Thread Starter
Compression ratio 11.3 only required 87 octane ???
I leaned about Hyundai Sonata and Kia optima 2011 both have higher CR than TSX, but manal only required 87 octane. How dose this happen without encountering knocking and pinging? Please advice.
#2
Moderator
iTrader: (1)
Originally Posted by from wiki
Due to pinging (detonation), the compression ratio in a gasoline or petrol-powered engine will usually not be much higher than 10:1, although some production automotive engines built for high-performance from 1955–1972 had compression ratios as high as 13.0:1, which could run safely on the high-octane leaded gasoline then available.
A technique used to prevent the onset of knock is the high "swirl" engine that forces the intake charge to adopt a very fast circular rotation in the cylinder during compression that provides quicker and more complete combustion. Recently, with the addition of variable valve timing and knock sensors to delay ignition timing, it is possible to manufacture gasoline engines with compression ratios of over 11:1 that can use 87 MON (octane rating) fuel.
Knock sensors, retarding the ECU, etc. which in turn LOWERS performance.
in the 3rd Gen TL, if we put a lower octane fuel, the ECU will retard timing thus lowering maximum HP and lowering fuel economy.
Last edited by justnspace; 04-05-2011 at 09:16 AM.
#4
Instructor
Thread Starter
despite lower performance, what about pinging or knocking possibility? Are they really able to 100% elimate by using 87 octane.
If so, why Acura can't . I use 93 octane all times, still has pinging issue. Do you think dealer can update ECU to 100% elimate pinging if i am willing to potential power loss?
If so, why Acura can't . I use 93 octane all times, still has pinging issue. Do you think dealer can update ECU to 100% elimate pinging if i am willing to potential power loss?
#6
i wouldnt be surprised if you had knock, get it fixed via the TSB if you really have knock at 93/91
#8
Senior Moderator
Join Date: May 2003
Location: Better Neighborhood, Arizona
Posts: 45,634
Received 2,328 Likes
on
1,308 Posts
Are those engines direct injection? That might explain why.
#9
did you buy a fucking tsx or something justin and ur not telling us about it?
https://acurazine.com/forums/showpos...&postcount=456
https://acurazine.com/forums/showpos...&postcount=456
#11
i got this, if you got direct injection, it jizzes fuel straight into the combustion chamber instead of mixing it first with air. Since it burns more efficiently and mixes better when it gets bukkaked into the chamber you can use a lower octane rating to achieve similar performance
i think, yo
PEEEENISSSSSSSSS
i think, yo
PEEEENISSSSSSSSS
#12
Senior Moderator
Join Date: May 2003
Location: Better Neighborhood, Arizona
Posts: 45,634
Received 2,328 Likes
on
1,308 Posts
Short answer, with direct injection gasoline is injected into each cylinder individually at very high pressure instead of in the intake tract.
The above answer is crude but accurate
The above answer is crude but accurate
#13
Instructor
Thread Starter
I am not saying it is knock, but i am pretty sure it is pinging around 2000rpm (dealer confirmed), mostly happen when you from stop to start. I have TSB 09-041 done about 6 months ago by dealer, but i doubt, beacuse they are not willing to have this TSB done until I asked for it. They just ask me to switch to 93, then I told them I use 93 from day 1 of owning the car. than they ask me to get Exxon 93. I have Exxon 93 for 3 tanks now, but still. It is not loud, but 100% annoyed. any suggestions.
#14
Rich and Famous
You might remember those Mighty Muscle cars of the 60's and 70's ...
I do ... and they knocked, pinged, and had post ignition to gazoo despite what gas used.
The Hyundai Sonata has
1. 198 hp 11.3 : 1 CR with 2.4 L Direct Injection or ...
2. 274 hp 9.5 : 1 CR with 2.0 Turbo I4 Direct Injection
F.W.I.W. on my '11 MDX with 11.2 : 1 ratio I use a mix of 93 and 89 octane {91 effective} and have no problem.
I do ... and they knocked, pinged, and had post ignition to gazoo despite what gas used.
The Hyundai Sonata has
1. 198 hp 11.3 : 1 CR with 2.4 L Direct Injection or ...
2. 274 hp 9.5 : 1 CR with 2.0 Turbo I4 Direct Injection
F.W.I.W. on my '11 MDX with 11.2 : 1 ratio I use a mix of 93 and 89 octane {91 effective} and have no problem.
#15
it's a car-drive it
for me-: because it works=excellent gas mileage and no power loss-121,000 problem free miles and counting. Had the car serviced recently by the local acura dealer in NC. I go there when I can not get to the dealer in PA. They complimented me on how well the car was maintained and it did not need anything.
#17
Team Owner
You can't have preignition with DI. You can have detonation but if the fuel is not in the cyinder yet, it can't pre-ignite. That's why guys are able to run 10+psi boost on top of 11:1 compression on pump gas.
DI has it's own issues though. I won't get one just yet until they get the intake tract carbon issues, fuel contamination of the oil, and cylinder wall washdown taken care of.
From a power standpoint, the only disadvantage is that the fuel does not mix with the air to cool it before it enters the combustion chamber but the added compression ratio and/or boost more than makes up for it.
I think this is the wave of the future but it still has some kinks that need to be worked out.
DI has it's own issues though. I won't get one just yet until they get the intake tract carbon issues, fuel contamination of the oil, and cylinder wall washdown taken care of.
From a power standpoint, the only disadvantage is that the fuel does not mix with the air to cool it before it enters the combustion chamber but the added compression ratio and/or boost more than makes up for it.
I think this is the wave of the future but it still has some kinks that need to be worked out.
Last edited by I hate cars; 04-06-2011 at 02:00 PM.
#18
I have a 09 TSX tech and it does pinging between 2000~ 2300 rpm.
Of course I went to dealer and they were like, there is no knocking/pinging noise from my car.
I already figured out this is not a pinging noise.
this is pre ignition noise from wrong knocking sensor design.
This is common problem I think for the 09 TSX
and they should fix this problem...
I will go see my dealer to fix this problem in this week,
if I am not busy...
Of course I went to dealer and they were like, there is no knocking/pinging noise from my car.
I already figured out this is not a pinging noise.
this is pre ignition noise from wrong knocking sensor design.
This is common problem I think for the 09 TSX
and they should fix this problem...
I will go see my dealer to fix this problem in this week,
if I am not busy...
Thread
Thread Starter
Forum
Replies
Last Post
joflewbyu2
5G TLX (2015-2020)
105
08-18-2019 10:38 PM
Biggie_B
5G TLX (2015-2020)
12
02-26-2017 11:14 AM