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What problems to look for if you run lean?


randy

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I have a serious feeling that I am running lean at say a fixed RPM like around 5k-7k. Cause I hear a strange noise {ping or metal kinda bang} like when I hold my revs between 5k-7k. Could this ping sound be something related to insufficent fuel? How does one tell if they are running lean? What can I do to run a little rich.

ALSO~ When I run the car on WOT it does not happen.

This happens when running anything above 15psi.:conf:

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Originally posted by randy

I have a serious feeling that I am running lean at say a fixed RPM like around 5k-7k. Cause I hear a strange noise {ping or metal kinda bang} like when I hold my revs between 5k-7k. Could this ping sound be something related to insufficent fuel? How does one tell if they are running lean? What can I do to run a little rich.

ALSO~ When I run the car on WOT it does not happen.

This happens when running anything above 15psi.:conf:

 

It sounds like detonation from what I have heard if you can actually hear it whilst driving you are doing a great deal of damage to your engine.

 

I get the impression from Supraforums that you run very high boost levels for a J-spec car in what must be high air temperatures. Whilst I appreciate that damage to your turbo's is an acceptable route to a turbo upgrade in your eyes (correct me if I am wrong here) I fear you may well be damaging a very expensive engine at the same time. :(

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TIME OUT GUYS!! :eek: 21PSI WAY!! I have never run my car above 1.3bar max and have done so rarely! On a regular basis I run only 1- 1.1 bar boost!! Also I have made a big change with my fuel since I was told not to run the car on hi-boost condition with poor fuel. I am running now close to 100 octane fuel.

I know what detonation is and believe me this is not detonation due to boost this happens when running the car without the Boost Controller on and at 1bar too!

I agree I must have asked questions on running high boost here and (supraforums) as I wanted to know what performace one can get with the stock turbos but have never needed to go beyond the 1.3bar mark.

Also the performance I got at 1.3bar was out of this world!! :thumbs: and I did not need to and want to go beyond this.:D I do this only at night at lower temps outside 19 deg C.

Gavin,

NO WAY IN HELL WILL I TRASH MY CAR! I have the only one good quality supra tt available in India, among the 2 supra tt here in India. :)

http://www.geocities.com/randymurthy2002/00007.JPG

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Originally posted by randy

Cause I hear a strange noise {ping or metal kinda bang} like when I hold my revs between 5k-7k.

 

Det is more like a "tinkling" noise (unless it gets really bad). It can be caused by high combustion temperatures, high cylinder pressures, and a lean mixture.

 

And if you do it for a long time, you WILL trash your car. Won't he, Ian? :eek:

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:baa:

 

Although I don't mind being an example (I mean, we give Keith enough stick, so I have to take it as well!), can I just point out once again that

a) I didn't know much about turbocharged cars back then, and due to that

b) I foolishly trusted the tuning company that blithely reassured me that the fuelling was 'spot-on' when I asked them, so

c) it wasn't my fault, my tinkering, or anything.

 

And I think it's OK from a legal standpoint to say that RC Developments reassured me that the fuelling was OK. Then my car blew up because the fuelling wasn't OK. Verified by our main man Chris Wilson himself, post-engine-swap. Make up your own mind who's the incompetent shifty bastards*

 

Bitter? You would be too, £5,000ish later... Another good reason for me to be an example, I don't want other Supra owners to go through that!!

 

-Ian

 

*it's not me or Chris

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Hello my friend Gavin! you just proved my point!! "running nearly 20psi/1.35bar boost" What it says is nearly 1.35 NOT confirming 1.35BAR!! also I actually did about 1.3/bar only as I stated!:baa:

 

Also guys this is not a pinging kinda noise at all! It is just a single clank like sound that happens when you run even on low boost!!!!

What I need to know is "How does one know if you are running lean?" What can be done to increase your fuel? Also could a fuel filter that is dirty cause this problem?:)

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Randy I'm not about to argue the toss with you about 0.5 of a bar. But if you read that thread in full you are advised that over 17 psi is bad for j-spec turbos. You agree with the statement but also make the following statements:

 

Running the stock Jap spec turbos for now till they blow after will upgrade!

 

But are more likely to blow as they are not capable of running more than say 18psi for long periods of time. Ceramic blades disentegrate! :D

 

Now given that are happy too run your car at boost pressures in excess of what you agree yourself is safe and reasonable not too mention timing as fast as possible 0-60 times in your car is hardly most people definition of someone who looks after there car. So lets cut the crap shall we :mad:

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OK! OK! I agree you guys in the UK have come to the consensus on max turbo pressure not to exceed 17psi for jap spec turbos. I have come to the understanding running anything more than stock boost is also bad for turbo longetivity not 17/18/19 even 15! So I guess it just means your turbos will last 6months longer than mine!:D I have no problems with that!!

Point*

Also I am not an old foggy to drive my car as if it were a saloon! We have a supra and should enjoy the power wether it means running the car hard on a track or doing times whether 0-60,0-100 OR 1/4mile! It is just personal as to how one enjoys there sports machine!:D :cool:

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