Supra TT question?

[Bobbeh]

Darren, wasnt that Pheonix, in Watford?

[Fifty]

 

Forgetting about Anh form a minute all this new member asked for was a little help.

When you put probably all the money you have into a car; and it doesnt feel like its running well; then we all feel like asking for something we can do to put our minds at rest. This seems like all the guy wants is reassurance?

 

There are some well known causes of this loss of 2 turbo or that missing power at 4000 rpm. They all get to that in the end cos the system ages.

 

I would be intrested for Freddy to report back.

 

eg.somewhere on here by Ian R I think is an excellent guide showing how the turbos work and what to look for if things dont seem right.

Rich:d

[Anh]

 

Forgetting about Anh form a minute all this new member asked for was a little help.

When you put probably all the money you have into a car; and it doesnt feel like its running well; then we all feel like asking for something we can do to put our minds at rest. This seems like all the guy wants is reassurance?

 

There are some well known causes of this loss of 2 turbo or that missing power at 4000 rpm. They all get to that in the end cos the system ages.

 

I would be intrested for Freddy to report back.

 

eg.somewhere on here by Ian R I think is an excellent guide showing how the turbos work and what to look for if things dont seem right.

Rich:d

 

 

Or he could just do a simple acceleration test to see if the car performs like it should. Anyone with some standard mid-range acceleration times for reference?

 

Bum on seat dyno/diagnostics should never be trusted.

[wkdtime]

 

Forgetting about Anh form a minute all this new member asked for was a little help.

When you put probably all the money you have into a car; and it doesnt feel like its running well; then we all feel like asking for something we can do to put our minds at rest. This seems like all the guy wants is reassurance?

 

There are some well known causes of this loss of 2 turbo or that missing power at 4000 rpm. They all get to that in the end cos the system ages.

 

I would be intrested for Freddy to report back.

 

eg.somewhere on here by Ian R I think is an excellent guide showing how the turbos work and what to look for if things dont seem right.

Rich:d

 

 

I have sort of spoken to him via pm, offered to have a look at it for him as im sure its the same problem as this

http://http://www.mkivsupra.net/vbb/showthread.php?t=73814

 

Which i helped Jonboy to sort out Via a phone convo as its the same problem i had.

 

So Freddy is in good hands:) a few other member have also offered to have a look at his car, which IMHO is the best way to diagnose a boost problem.

[wkdtime]

Or he could just do a simple acceleration test to see if the car performs like it should. Anyone with some standard mid-range acceleration times for reference?

 

Bum on seat dyno/diagnostics should never be trusted.

 

Thats an inpractical way to find out if its underperforming...unless he has access to a track.

 

As stated in my previous post the best way to diagnose the problem is to take it to someone who already has the same car or knows the Supra very well and thus can make comparisons and diagnostics.

[Scoboblio]

Gentlemen, please allow me to display my god-like technical knowledge by cutting and pasting the following from IanC's FAQ;

 

Problem 1: I don't get a 2nd turbo rush, it just seems to sit at 0.8bar.

The second turbo isn't kicking in. This usually means your IACV isn't opening - the turbo is trying to spin up but can't flow any air, so #1 turbo does all the hard work.

 

By the time #1 turbo is producing 0.8bar at 5000rpm it's way beyond it's efficiency map and is overheating the air and overspeeding the turbine. Try not to do this too often.

 

 

edited: typo

[Anh]

Its not hard to perform a simple 30-70 mph test.

 

Standard JZA80 does it between 4 to 5 seconds. If the 2nd turbo does not work, or there is some boost leak, the car would be far from that time.

 

It doesnt identify the cause to the problem, but sure does identify if there *is* a problem.

[wkdtime]

Gentlemen, please allow me to display my god-like technical knowledge by cutting and pasting the following from IanC's FAQ;

 

Problem 1: I don't get a 2nd turbo rush, it just seems to sit at 0.8bar.

The second turbo isn't kicking in. This usually means your IACV isn't opening - the turbo is trying to spin up but can't flow any air, so #1 turbo does all the hard work.

 

By the time #1 turbo is producing 0.8bar at 5000rpm it's way beyond it's efficiency map and is overheating the air and overspeeding the turbine. Try not to do this too often.

 

 

edited: typo

 

Exactly what i think is the problem with Freddys and there is a very simple way to test if this is the case as Jonboy found out;)

[Thorin]

Its not hard to perform a simple 30-70 mph test.

 

It is if you're the only one in the car to time it.

[Jake]

I have sort of spoken to him via pm, offered to have a look at it for him as im sure its the same problem as this

http://www.mkivsupra.net/vbb/showthread.php?t=73814

 

Which i helped Jonboy to sort out Via a phone convo as its the same problem i had.

Exactly what i think is the problem with Freddys and there is a very simple way to test if this is the case as Jonboy found out;)

 

What did you advise Jonboy to do then? As far as I know his car is still running TTC because he still has the problem of it not boosting beyond 0.8bar in regular sequential mode. Am I reading your post correctly? Sounds like the problem with Jon's car is fixed

[Fifty]

Apologies to Ian C who I misquoted as Ian R

I am now going to exit this thread , leaving it to the experts lol

 

Rich:d

[wkdtime]

What did you advise Jonboy to do then? As far as I know his car is still running TTC because he still has the problem of it not boosting beyond 0.8bar in regular sequential mode. Am I reading your post correctly? Sounds like the problem with Jon's car is fixed

 

oops my bad, bad wording, i mean to say its been diagnosed as a faulty IACV as it does not open to allow number 2 to flow air, and it runs fine in TTC as the IACV is by passed.

 

So all he needs to do is to replace the IACV and hes sorted.

[Guest freddyk]

Couldnt meet wkdtime on the weekend although I wanted to compare cars so badly but i will try resetting the ECU tonight and test after that. According to the messages it sounds to be this IACV problem as that's the problem I am having, I believe.

 

I will try 30-70 mph test tonight as well. What is the average timing for supras? And how can i test it? Must I drive in idle speed of 30mph and then initiate the boost and time it?

 

thanks a bunch to everyone who is interested

[Homer]

I will try 30-70 mph test tonight as well. What is the average timing for supras? And how can i test it? Must I drive in idle speed of 30mph and then initiate the boost and time it?

 

Ignore that advise, the guy is talking b*llocks, the test won't show you anything valuable. Best to get it to a garage (or a local club member) who knows their way round the sequential system.

[pistonbroke]

I'm going to meet freddy tomorrow evening and compare supras, Freddy, is your car totally standard?, does it have a boost gauge?.

 

If its got any tricks up its sleeve then its going to be different to mine, as mines completely stock. (apart from exhaust and dump valve)

 

I'll also confess now that apart from basic mechanical knowledge about cars, I'm not an auto technician, and I'm no proffesional when it comes to sequential turbo systems.

 

I just hope I can help provide you with solace that your car is fine, or point you in the right direction if its not.

 

I'll bring my multimeter along and test your HEGO sensor to see if the car is running proper mixtures.

 

I've also noticed you said you can't hear the second turbo come on, if you've got the standard airbox, you can't hear the second turbo anyway, you can just hear the whistle of the first one.

 

Anyway, I'll see you tomorrow evening.

[wkdtime]

Freddy let me know how it goes with Pistonbroke, hope you get it sorted mate. A boost gauge would prove to be very handy.

[ardasaliah]

get a boost guage. that will tell you if you have a problem

[Anh]

Couldnt meet wkdtime on the weekend although I wanted to compare cars so badly but i will try resetting the ECU tonight and test after that. According to the messages it sounds to be this IACV problem as that's the problem I am having, I believe.

 

I will try 30-70 mph test tonight as well. What is the average timing for supras? And how can i test it? Must I drive in idle speed of 30mph and then initiate the boost and time it?

 

thanks a bunch to everyone who is interested

 

It is around 4 to 5 seconds, depending on a manual or auto, a few MKIV owners I know have done these little fun tests and pull of times within this range, if your car gets between those times then there doesnt seem to be a performance problem with the car.

[Guest freddyk]

I dont think I have a boost gauge. I will meet pistonbroke this evening and it will be a good experience for me, thanks a lot for that, again. I will let you know, how it goes after that.

 

Btw, the car is auto and 5.55 is the time for 30-70mph which is not very very good, i guess.

[pistonbroke]

Ok, I've seen freddyk's car, it took me all of three minutes to find the fault. His viscous coupling on the radiator fan is sticky, the tell tale whooshing droning noise gave it away, I free revved mine next to it and it made no noise at all.

 

Well there you go freddyk, you've got your moneys worth out of this club membership already

 

I'm 110% sure this its whats sucking the power from his engine.

 

EDIT :- almost forgot to mention, nice to meet you matey, what is it with Supra owners having fit other halfs, Freddyk, as payment for me and the boys services and advice to you on this club, you can post a picture of the lady that was with you along with some hovis. Don't ask me why, thats just the way it is.

[wkdtime]

Fit car...Fit Mrs...always the case, if not then brush up on your pulling techniques:D

[Anh]

I dont think I have a boost gauge. I will meet pistonbroke this evening and it will be a good experience for me, thanks a lot for that, again. I will let you know, how it goes after that.

 

Btw, the car is auto and 5.55 is the time for 30-70mph which is not very very good, i guess.

 

Thats about right for an auto, especially with today's hot weather.

[Guest freddyk]

Thanks to pistonbroke, he diagnosed the problem that I will never find out by myself. His car was really beautiful btw. I will post the pictures of my car after i will change my alloys and polish it and maybe if you're lucky you'll see mrs, too Supras and fit mrs go well together I believe, too

 

As I told pistonbroke, I would like to attend some events so i think i must keep my eyes open here. It was nice to meet him and he was very helpful.

 

About the 30-70mph performance 5.55secs was at night in a cool weather and the car was always in a garage at daytime which is all the time cool.

[Anh]

Thanks to pistonbroke, he diagnosed the problem that I will never find out by myself. His car was really beautiful btw. I will post the pictures of my car after i will change my alloys and polish it and maybe if you're lucky you'll see mrs, too Supras and fit mrs go well together I believe, too

 

As I told pistonbroke, I would like to attend some events so i think i must keep my eyes open here. It was nice to meet him and he was very helpful.

 

About the 30-70mph performance 5.55secs was at night in a cool weather and the car was always in a garage at daytime which is all the time cool.

 

It's still about right. The worst time I seen from a healthy working auto supra is 5.7 seconds, so your times are not out of the ordinary.

 

Engine Horsepower is rated with 10 deg c air temps, while you are taking about 15-20 deg air temps in the evenings this week!

[pistonbroke]

Well, the sticky viscous coupling on his fan is definitely causing issues as its theoretically increasing rotational mass on the engine.

 

If he replaces the fan, he will get a noticable improvement.

 

EDIT :_ thanks for the compliments on the car freddyk, it makes it all worth while when someone comments on your pride and joy.