Fabio421

There is a universal HUD on the market. Its very affordable. So affordable in fact that I wonder how well it works. LOL I'm thinking about buying one to play with once I get my car back on the road. http://www.tsperformance.com/mpd_monitor.html

AO

Yep, I agree. That is how it's supposed to work. My experience is that it rarely does. In fact I don't know of any boosted 928 that does not have some type of AFR gauge.

How will you know when the MAF starts going out?

And I know it's not a money thing. I would put one in at least for a few months as you get to know the car. But it's your project, you do what you feel is right.

ptuomov

That would not be good, especially considering that the fuel pump speed will be controlled by the MAF signal.

Imo000

Don't need a boost gauge on a turbo either. You can learn very qucikly by feel how to drive one to it's full potential. It's a toy that looks good. If anything, you should have an A/F instead of the boost gauge.

ptuomov

Of course you don't really need it, but the boost gauge or turbocharger speed gauge are IMO useful when cruising and deciding to pass someone, or when entering a highway off a ramp. But you're right, it's not in a strict sense needed -- one has a feel of it. It's about 95% about psychology why factories included boost gauges in the 80's and 90's cars.

I understand that when developing, tuning, or debugging a car, AFR gauge is useful. Beyond that, when the car is finish, an audible alert or a warning light when it's either lean or rich will IMO be enough.

In any case, so many people here seem to think that AFR gauge is a high priority that I'll think about whether I need to rethink the gauge plan. One possibility would be to make the 951 boost gauge switchable between multiple 0-4.5 inputs and include AFR as one of them. Or something. Ill think about it.

Imo000

You are contradicting yourself. The only difference between what we say and you say is the methos of display. You are after an audible warning (still needs an A/F sensor of some sort) and we are saying that the visual one is the way to go. So if you think about it, at the end, we are both talking about the same exact thing...... a way to monitor the A/F ratio.

ptuomov

I'd much rather be inconsistent than wrong! ;-)

If you read my posts from the get go, the plan is and always has been to have a wideband AFR sensor in the car. I definitely want to log that. I want to log a lot of other stuff as well.

In addition, I want to set audible alerts for error events. I think I've been consistent about that.

What I have an issue with is too many gauges. Right now, there will be eboost2 (necessary for switching boost programs) and turbine speed sensor semi permanently installed. I say semipermanently, because once eboost2 is set to operate from the gear position and once boost / turbine speed is displayed on the 951 gauge, the ash tray is coming back -- eboost2 will go inside the glove box and turbine speed gauge to the garage shelf.

Imo000

Turbine speed? Interesting. Are you planning on running them right at the limit?

Tony

The guy has a damn N2 gauge in his car! Love it!

That work John has done is OFF THE CHARTS!..so is the dyno

I dunno about you guys, but ive got a little line up of gauges under my dash.
Boost/vac...fuel pressure...ARM1(narrow band) .. Inovate wideband.....tranny temp..oil temp...water temp....each one of them has helped me trouble shoot an issue in the past! Johns set up seems well sorted so Im sure you may not need them....it would be a good idea though.

today i was hammering the car hard from the airport in the heat..with the AC on seeing how hot it would run. Just as i pulled into the garage the red temp band illuminated. Guess what, the needle was perfectly horizontal... " NORMAL"...my autometer gauge showed well north of 240ish degrees!
Water was bubbling in the hoses/system when i popped the hood!

ptuomov

That sensor is for a couple of purposes.

First, I want to figure out if the bypass valve spring has the right load. One doesn't want the turbine to slow down or the boost to drop during shifts, if possible.

Second, for air flow modeling purposes, I need to know where I am on the compressor map at each point in time.

Third, I'll be exploring the possibility to set up a turbine overspeed alert based on that sensor output.

All of these require using and/or logging the sensor output, but not a gauge. The gauge is a bit of a gimmick. It'll be useful in development, debugging, and tuning. Beyond that it's probably not that useful.

What's an N2 gauge?

That's so true. So far, by the way, this is all John's work. I am basically a distant bystander.

I can't wait to get my car on a dyno. Remember, it has larger turbos than John's twin turbo. John's twin turbo has gt2871rs, mine has gt3071rs. So it should spool a bit later but I should be able to run it to a very high exhaust flow level without much back pressure.

That's a good example. Effectively, the factory "gauge" is really a sort of a warning light with three positions: too cold, just right, too hot. For a car that is completely developed, that's all one needs.

What you are describing is development effort, testing. Of course, for testing, data logging and gauges are useful.

On cooling: John's system has an external water pump and a controller that will run the coolant for a set time (currently 5 min) after the car has been shut down. This will help the cooldown of the turbos. The system is set to be as fool proof as possible.

slate blue

Tuomo forgive me but I haven't read the whole thread, don't know much about turbos. If you are looking for a great engine management system, Cosworth make it and it has incredible power and their logging capacity is also huge, the pound is really weak and all options are enabled. 3500 pounds gets you the SQM6.


Greg

AO

Tuomo,
It sounds from your posts that you think/believe John's system is complete and that all the development work is finished. Hence, you don't need the AFR and other gauges.

I think this is a false assumption. I'm sure John has done extensive testing and believes it will be a turn-key system, but you;ve already added a different variable with the different turbos.

I have found that each boosted car runs slightly different. A case in point:

I recently gave a set of chips that works great on my car to someone running the same setup as me. His car wouldn't even start. He put his chips back in, and it started right up.

No matter your decision, (and it is your decision) we are looking forward to your maiden voyage and a dyno report. Should be some rather large numbers.

ptuomov

Once we get the first iteration on a dyno, I'll post the dyno graphs. I am expecting slightly above 500hp for the fool-proof safe setup. I understand that, at this point, this claim/hope and $1.89 will get you a cup of coffee at Starbux, since the car's not even running yet. ;-)

It'll have the wideband AFR sensor forever and the temprorary gauge until it's fully debugged and tuned. I don't want to burn down this engine before I got data logging set up.

However, once data logging is set up, my plan is to do some potentially destructive testing with the stock engine and get some data. Then, I'll drop in the engine built by Jim Morton (in many ways similar to Dennis Kao's engine but with significantly less compression).

ptuomov

This is how turbos are cooled. First, the coolant gets picked up from the water line. The pipe section has a pitot tube for pickup and a slash cut tube for exit. This pitot/slash design will assist with coolant flow. Also, it adds distance between the pickup and the exit, which helps during the 5 minute shut off cool down.



The water is circulated using a pump. Although the pitot and slash cut tubes assist, the pump does the heavy lifting. As mentioned above, the pump has a controller that runs it for a set period after shutdown, currently 5 minutes.

Here are the coolant hoses, being routed to the turbo center housing. The point is not to cool the turbine housing or anything, just the center housing in which the dual ball bearing cartridge lives. Because of the proximity to the turbine, everything has to be metal braided or metal hard line.



The metal surface helps hugely in cooling the lines, because it conducts the heat to a large area and then acts like a mini radiator. The only problem with stainless steel braided lines is that they can grind a hole in almost anything if not securely fastened. In risky areas, the ss braided hose is routed thru a rubber hose.

This is still work in progress, but it's getting really close. We're behind the schedule, but I think its ok since the delays have been caused by decisions not to cut corners.

hacker-pschorr

+1
Nasty slivers too
I try to avoid using SS lines, but in some situations it's simply the best hose for the job.

Any need for a "turbo timer" or coolant pump after the car is shut off anymore? I may be behind the times on this, just remember my friends installing those on their turbo cars back in the day.

Looking good! Bet the butterflies are really picking up the closer you get to turn key.