Finding MBT without dyno?

4g94T · Jun 17, 2009, 03:49 PM

Is it possible to find MBT without a dyno?
I know many EVOs are street tuned, but how do you find MBT?

My car is on e85 only and with e85 it is easy to pass MBT without any signs of knock.

Any advice on what to look for in the logs or use of any other logging tools?

Any help is appreciated

TouringBubble · Jun 18, 2009, 01:09 PM

You can use DataLogLab to track TQ using RPM/time. You can use the Evo base car definition with the gearing changed to match the Lancer. The numbers will be close, but not perfect. However, the gains/losses will be consistent if you use the same stretch of road.

4g94T · Jun 18, 2009, 02:33 PM

Thanks TB. Where can I find this dataloglab?

4g94T · Jun 18, 2009, 10:19 PM

alright so i downloaded the trial version, lets see if i can get this running.

i am using mitsulogger and do not have evoscan.

how do i change the evo base car definition to match the gearing of my lancer?

4g94T · Jun 19, 2009, 03:11 AM

looks like i got it running.

i changed the values in the evo car definition to match the lancer's gear ratios, weight, and my tire size. i left the default drive train % lost for each gear as i do not know those values for the lancer.

any advice on the tune from the graph below? torque drops so much and horsepower seems to be low.

senate6268 · Jun 19, 2009, 11:26 AM

Quote:

Originally Posted by 4g94T

looks like i got it running.

i changed the values in the evo car definition to match the lancer's gear ratios, weight, and my tire size. i left the default drive train % lost for each gear as i do not know those values for the lancer.

any advice on the tune from the graph below? torque drops so much and horsepower seems to be low.

Sadly, the torque curve is pretty accurate. Our engines make peak torque around 4000rpm without any head mods and it falls off from there. You can thank the 95.8mm stroke and tiny bore for that. You're right about the HP. It does seems a bit low. However, the shape of the curve looks right. Focus on tuning your timing above 4300rpm. Other than that, ported head, intake manifold, throttle body and cam are the answer.

4g94T · Jun 19, 2009, 11:39 AM

Quote:

Originally Posted by senate6268

Sadly, the torque curve is pretty accurate. Our engines make peak torque around 4000rpm without any head mods and it falls off from there. You can thank the 95.8mm stroke and tiny bore for that. You're right about the HP. It does seems a bit low. However, the shape of the curve looks right. Focus on tuning your timing above 4300rpm. Other than that, ported head, intake manifold, throttle body and cam are the answer.

thanks senate.

I added more timing up top and it maintained the same torque and horsepower, but the curve dipped much lower.
I will lower the timing a bit and see how that does, otherwise i am stuck here.

As for the low horsepower, would it help if I had a larger free flowing exhaust?
I still have the stock head, camshaft, TB, intake manifold on, and along with the stock MAF that I know is restricting airflow.
I am not also sure how efficient my intercooler is.

GST Motorsports · Jun 19, 2009, 11:47 AM

Did you get wheelspin in that datalog?

senate6268 · Jun 19, 2009, 12:36 PM

Quote:

Originally Posted by 4g94T

thanks senate.

I added more timing up top and it maintained the same torque and horsepower, but the curve dipped much lower.
I will lower the timing a bit and see how that does, otherwise i am stuck here.

As for the low horsepower, would it help if I had a larger free flowing exhaust?
I still have the stock head, camshaft, TB, intake manifold on, and along with the stock MAF that I know is restricting airflow.
I am not also sure how efficient my intercooler is.

A larger or more efficient exhaust isn't the current bottleneck in your setup. Every part you named: head, cam, TB, intake man and MAF are all restricting airflow when your engine is inhaling. At the very least you can pick up a 4G93 manifold to port or port your stock manifold for now. You will notice a nice improvement there. You can also pick up a MAF from a 4G64 or an Evo to install and correct the settings and scaling right in EcuFlash. Both MAFs are non-restrictive and pretty much a straight through design. You won't need to address the exhaust side until it has become a bottleneck.

Also, would I be correct in guessing you were in third gear for the logging?

*02Lancer* · Jun 19, 2009, 02:30 PM

So what is the most restrictive part in the 4g94 followed by the second and so on? In your opinion?

senate6268 · Jun 19, 2009, 04:10 PM

Quote:

Originally Posted by *02Lancer*

So what is the most restrictive part in the 4g94 followed by the second and so on? In your opinion?

The question itself merits a question. A bone stock 4G94, one with basic I/H/E, a turbo setup with nothing else? Cause without a turbo and the HP that it brings the restrictions on a N/A Lancer are minute. That's why N/A mods net little to nothing for gain.

On turbo Lancers the restrictions are all on the intake side. The engine runs out of airflow quickly and the powerband falls off, as the chart above shows. You need to focus on getting air to the head more efficiently. Once you've done that you can work on getting the head breathing more to allow for use of the increased airflow it is receiving. With a turbo, you have increased airflow on the intake side, but it is getting restricted before it even makes it to the cylinder head.

4g94T · Jun 20, 2009, 07:04 PM

heres my setup before E85.
+47 hp and +65 trq

and its almost a dollar cheaper than 91

stay tuned.

whenever i can my hands on wiseco pistons and ARP head studs i'll be installing all my parts thats been sitting around for months:
PnP head, RPW stage 2 camshaft, RPW valve springs, and Pauter Rods. but i'll still need a ported intake manifold and RPW's new 70mm TB.

i'll probably get it professionally tuned then.