We are rapidly approaching the completion of the assembly of our motor. We have decided to break it in and tune it on an engine dyno.

Has anyone on this form personally broken in and tuned their motor this way versus using the motor in car chassis dyno?

 

I did one about 15 years ago. What do you want to know, specifically?

Mike

 

Anything .......... your thoughts and experience using this method with this type of motor.

 

2 things I can think of...

1. Even engines that have been tuned on an engine dyno, usually require a fair amount of tuning when they are reinstalled in a chassis.

2. Breaking in a 996tt engine on an engine dyno will make re torquing head studs after the engine is heat cycled MUCH easier with far less labor!

 

heat cycle it warm up till the cylinder heads are too hot to touch and let cool off till ambient (2-3 times) and then retorque head studs then go about tuning. make idle adjustments and such during the warm ups but dont run her hard until you got about a good 20min solid for the valve train and bottom end to get acquainted and make sure there are no problems that will be very easy to hear in the room unless you happen to be running open exhaust then well that a different story

after a day of pulls i would re torque the heads one more time and then start er up n check it out one last time.

this is what ive done before on hi compression motors and turbo motors that were stretching engineering limits.

 

Tony,

I was explained the cold start and acceleration would need to be dialed in after the motor was installed in the car. Are you aware of anything else?

Yes, re torquing the heads along with finding any oil leaks are advantages. Knowing actual bhp numbers would be another.

I was explained that due to the control of water temperatures and IC flow much more work can be accomplished in the same period of time.

I was also explained the rings can be broken in with a high degree of precision.

I was interested in comments regarding the ability to accurately tune all aspects less cold start and acceleration.

 

What does Mr. Knighton have to say ? (They still have an engine Dyno at Proto
and certainly have done first tunes on it).

Good luck, Exciting project !

 

Yes, being able to "listen" to the motor would be a plus I could understand.

 

I have spoken with Todd and he will be a definite part of the tuning team. His understanding of the Porsche ECU is critical to our project.

The engine dyno we will be using is at Performance Developments. Todd agreed to participate on site and then he would take over the tune after it was installed in the chassis.

Our build is highly unorthodox. The motor has as large of a displacement as the stock case will physically allow. The present MAF's available (1200 hp ratings) are not large enough to work with the Porsche ECU due to flow provided by the displacement, intake, cams, piping, TB's, plenums, heads, etc. We have resorted to using a Speed Density application and will have to make our own graphs/data, etc. There will be added issues to control like dual injectors, multiple throttle bodies and dry nitrous. We will be utilizing a Porsche ECU, however all motor operations will be controlled by our own unit (developed outside the US) which works in conjunction with the Porsche ECU.

 

Environmental conditions are completely different on an engine dyno vs in the chassis. When your engine is in a chassis it is in a full enclosure vs in open air. This will effect the engines retention of heat which can greatly effect tune. On the engine dyno, the engine is solidly mounted. This different vibration characteristics will effect knock sensor feedback. Difference in paristalic drag will effect coast down, "tip in" and light load cruising conditions .

As you mentioned you will wont be able to tune cold start, acceleration enrichment, boost control, etc.

Engine dynos car a great tool however in most cases it cant be used to produce a "final" tune.

I see you are using a 2nd ecu and are working with PD... Are you using a Link g4?

 

Tony,

Yes, Link is involved. What has been done goes further than g4 capabilities. We can change one code and know all other codes that change affects. I believe this development leap frogs ahead of Motec. Much has been developed. What was previously not possible has now is able to be understood, identified and resolved.

You are correct in the fact the engine dyno will not be the final tune. This is why Todd Knighten is a vital part of the team (for the engine dyno) and will be responsible for the final tune with the chassis dyno. With the system Link is coming up with, the tuner can easily have (complete) control of all motor functions in his facility. Speed Density does not necessarily have to be utilized if you are not greatly exceeding 1200 hp. The system will also work with MAF.

 

My experience was with a nissan inline 6 motor. It was easy to dial everything in and make changes to things like "valve spring adjustments" and headstud torquing. We did about 6 hours worth of work dialing in the motor. However, you'll have to go back and dial it in once it's in the chassis, as Tony mentioned.

Mike

 

in my eyes you have one of the best tuners in the market tuning the motor i am sure he would be your best source of knowledge in this matter.

keep us posted!

 

The link/vi-pec ecu's have come along way in the past few years. We have used them in many Porsche projects ourself.

Good luck with the project!