wisp of smoke under boost?

[mrvetten]

I did check all the plugs recently (about a week ago) when I replaced them and they were clean, no piston. I suppose that is in part to my decrease in boost. As I said I was only running 14psi or so and I have a ProFec E-01 boost controller, which I was under the impression that these electronic controllers controlled boost creep. (Is that true in your opinion?) I have a HKS EVC IV on my 69 Camaro and it works mint.

I actually have a set of 720cc injectors and a HKS fuel rail, I just wasn't going to put them on until I installed an AEM ECU. When I installed the T72, I re-dynoed the car to make sure there were no changes. As it happened, it was quite a bit leaner with the increased volume, so based on my A/F ratio, I ended up at 14 psi or so and it seems safe. Is it possible that the A/F is safe (around 11.0-11.5?) yet still run lean and/or detonate?

I thought (from reading many of these posts) that a stock Supra fuel system can support UP TO 500hp or so. My car was only around 460ish rwhp with the T61, and as I recall, right around 430-440 now with less boost, even though more turbo. What do you think?

It sounds like I need to do a comp test anyway just to insure there is no damage. I have a little piece of mind after seeing my plugs, but your right, proof is on the pressure gauge.

I know this info is here somewhere but what should I see for cylinder pressure, and the minimum delta from cyl to cyl?

Might take a little time to check it, but I will do it.

I am leaning also towards some kind of stupid oil leak. I think dyno is the best and easiest and safest way to find this out.

Look forward to your reply. Thanks again for your input. gotta go to bed, 4:30 comes quick...
Mike

[pwpanas]

Originally Posted by mrvetten

I did check all the plugs recently (about a week ago) when I replaced them and they were clean, no piston. I suppose that is in part to my decrease in boost. As I said I was only running 14psi or so and I have a ProFec E-01 boost controller, which I was under the impression that these electronic controllers controlled boost creep. (Is that true in your opinion?)...

Unfortunately, no...boost controllers only control the wastegate, which only indirectly affects boost.

Originally Posted by mrvetten

...I have a HKS EVC IV on my 69 Camaro and it works mint...

I suspect you're running a lot less boost on your Camaro. A larger V8 also has a lot more exhaust volume at low rpms, which tends to drive the turbo with a bit more stability.

Originally Posted by mrvetten

...I actually have a set of 720cc injectors and a HKS fuel rail, I just wasn't going to put them on until I installed an AEM ECU...

Fwiw, I'd advise against that plan. In general, you need to be able to flow enough fuel to match the max airflow of the turbo.

Originally Posted by mrvetten

...When I installed the T72, I re-dynoed the car to make sure there were no changes. As it happened, it was quite a bit leaner with the increased volume, so based on my A/F ratio, I ended up at 14 psi or so and it seems safe. Is it possible that the A/F is safe (around 11.0-11.5?) yet still run lean and/or detonate?...

At 14psi on 93 octane gas you won't detonate. Again, the trouble is, with a turbo that big it's nearly impossible to consistently regulate it down to 14psi using wastegate control alone.

Originally Posted by mrvetten

...I thought (from reading many of these posts) that a stock Supra fuel system can support UP TO 500hp or so...

Correct. In fact, it'll support 500rwhp or so (depending on whether we're going through a 6spd or an auto).

Originally Posted by mrvetten

...My car was only around 460ish rwhp with the T61, and as I recall, right around 430-440 now with less boost, even though more turbo. What do you think?...

The key is regulating that boost, and guaranteeing the low boost level with 100% certainty. For example, I'd put big $ on the table that (eg. with a 6spd) if you're cruising in 5th gear at about 65mph, downshift to 3rd and hammer it you can get your T72 to spike up over 20psi, even if your boost controller is set to 15psi. I wouldn't advise it however because at 20psi with that turbo your oem fuel system will run lean. If you also did it on pump gas (i.e. not race fuel), you'd detonate and probably pop the engine within a few seconds.

Originally Posted by mrvetten

...It sounds like I need to do a comp test anyway just to insure there is no damage...

Agreed 100%.

Originally Posted by mrvetten

...I have a little piece of mind after seeing my plugs, but your right, proof is on the pressure gauge...

Yep...it never hurts to know for sure.

Originally Posted by mrvetten

...I know this info is here somewhere but what should I see for cylinder pressure, and the minimum delta from cyl to cyl?...

Here are the factory instructions:
http://www.mkiv.com/manual/manualtt/...eck/index.html

Originally Posted by mrvetten

...I am leaning also towards some kind of stupid oil leak. I think dyno is the best and easiest and safest way to find this out...

What part of the car/engine/tranny is leaking?

P.S. Sorry for the delayed response. My computer was down due to a change in residence (i.e. moving).