Now using the MAP sensor..

[MPNick]

can you explain why MAF is better?

It is much better at reading total air flow then a MAP ever was, is or will be.

 

[igdrasil]

Well, the MPI was a bit rough on the timing side while out of boost if no modification is done (0 on timing), I thought that it could be a lag issue, so i started to add timing whenever he was out of boost and all went pretty smooth...no more bumpy 3krpms

On the downside, in my case I had noticeable pinging (ugly) while applying load on very low rpms and out of boost, sometimes while building the first 8psi's...maybe because too much timing advance was still there, some pinging was noticeable. Pulled 1 more degree off the boost retard down low and done.

Then if you try to start retarding too soon, low end torque is killed. And if you try to settle (0 timing advance or retard) on the boost threshold, you go into the bumpy threshold, its very minimal, but I think thats what we all refer.

Looks like a bit of timing advance is needed to keep up to the first 1-3psi to make a smooth power pickup, but you may experice some ping if you PUNCH IT and still have some advancing or no retard with a lot of boost.

 

[MPNick]

Well, the MPI was a bit rough on the timing side while out of boost if no modification is done (0 on timing), I thought that it could be a lag issue, so i started to add timing whenever he was out of boost and all went pretty smooth...no more bumpy 3krpms

On the downside, in my case I had noticeable pinging (ugly) while applying load on very low rpms and out of boost, sometimes while building the first 8psi's...maybe because too much timing advance was still there, some pinging was noticeable. Pulled 1 more degree off the boost retard down low and done.

Then if you try to start retarding too soon, low end torque is killed. And if you try to settle (0 timing advance or retard) on the boost threshold, you go into the bumpy threshold, its very minimal, but I think thats what we all refer.

Looks like a bit of timing advance is needed to keep up to the first 1-3psi to make a smooth power pickup, but you may experice some ping if you PUNCH IT and still have some advancing or no retard with a lot of boost.

I have seen where these cars do not like to have timing added at idle. After that adding some timing does help, but I do not like to add timing under boost. What kind of AFRs are you running at boost tip in?

 

[igdrasil]

I have seen where these cars do not like to have timing added at idle. After that adding some timing does help, but I do not like to add timing under boost. What kind of AFRs are you running at boost tip in?

Im not quite sure about the A/F, but with the vortech 12:1 right now, is just a bit lean because i had to pull some fuel out on some areas where the vortech adds too much, some that may be a threshold on some situations, but now im pulling -2 as the 1st psi comes.

 

[MPNick]

Im not quite sure about the A/F, but with the vortech 12:1 right now, is just a bit lean because i had to pull some fuel out on some areas where the vortech adds too much, some that may be a threshold on some situations, but now im pulling -2 as the 1st psi comes.

12 is not lean at 1 psi. It is very rich.

 

[70]

12 is not lean at 1 psi. It is very rich.

I don't think that's his A/F ratio. That is the ratio on his Vortech FMU he is running...

 

[igdrasil]

I don't think that's his A/F ratio. That is the ratio on his Vortech FMU he is running...

yeah 12:1 Vortech calibration.

This always creates confusion.

 

[acidbug]

(second) Glad to see you took my advice from over a year ago. Simple to tune this way, isn't it? Hopefully more people will start listening to me about it now. The easiest way to use the MPI tuner is...

-with an FM clamp
-with extra injectors, controlling only those injectors
-with a MAP sensor to sense boost
-to retard timing where necessar
-with a FCD, if necessary

Happy tuning.

Nope..the easiest..way..is to live close to MPI Nick..(like i do)..and have him help/tune my car!

 

[Bigg Tim]

The MPI is only doing what it was tuned to do. If it was fighting out of boost it was tuned wrong. If you are only adding fuel with the extra injectors under boost only that sounds right. But you could have done the same with the MAF. You do not need the MAP to do that.

If you still think the MAP is better for you there is a better way to use it then you are now.

So what's the better way to tune with it, how bout some elaboration????

 

[KzA]

yea....This whole MAP thing is really getttin me curious..it sounds like its good for the application, since the desired result is for it to drive stock before boost..

 

[MPNick]

yea....This whole MAP thing is really getttin me curious..it sounds like its good for the application, since the desired result is for it to drive stock before boost..

You can do that right now without use a MAP. You just need to move some wires.

 

[MPNick]

So what's the better way to tune with it, how bout some elaboration????

OK

 

[Bigg Tim]

OK

SOOOOOOO......where's it at?

 

[acidbug]

If you want your car to drive stock out of boost...do not alter the fuel curve before boost (My turbo spools aprox 27-2800rpms..so below 3,000rpms i do not add any fuel) in the mpi tuner software (Than in the TPS column i noticed that boost only comes in if i am at 18+ %throttle..so before 20% throttle i am not adding any fuel)..Also make sure you clamp is not coming on to soon (Mine is set for 63..but i really don't hit boost until 62.5 so i set it for 63...so it doesn't come on to soon and bog the engine)...If you do that properly..you should not be alterring the ecu's parameters...which should give you a smooth ride..out of boost...

One of these days when i upgrade to extra injectors (i don't see a need right now..b/c i am pushing 12psi and runing rich)...I will use the extra injectors to supply the majority of the fuel that the turbo needs to get my a/f in the 12's...But i will still tune with stock injectors so that i can add fuel when i enter boost...

Chas

 

[Kooldino]

Interesting...

So, you use the MPI to run the extra injectors and use the MAP to tell the MPI when to come on? Leave the stock injectors to be run by the ECU, and change timing with the MPI too.

Yes sir. Been that way for the past 14 months now.

Why is the FM clamp better than the turbo module?

It's simple, and it works. I have no experience with the turbo module, and I have no reason to use it.

Now, my other question is what other devices can run extra injectors in a similar manner that aren't as expensive?

There's tons of $300 injector controllers out there. Just not sure if they can retard timing in OUR cars.

 

[Kooldino]

The MPI is only doing what it was tuned to do. If it was fighting out of boost it was tuned wrong. If you are only adding fuel with the extra injectors under boost only that sounds right. But you could have done the same with the MAF. You do not need the MAP to do that.

If you still think the MAP is better for you there is a better way to use it then you are now.

I see a lot of people having tuning issues with the MPI, and I frequently see you blaming it on the person doing the tuning. Regardless if it's the person's fault or not, the MAP + extra injector way is easy for everyone to tune, and that's why I endorse it. It's simple, and it works. (cool)

 

[Kooldino]

It is much better at reading total air flow then a MAP ever was, is or will be.

Until you max out your MAF...and then you either need a bigger MAF or a MAP sensor.

My problem with MAF tuning is that it would see the same amount of air at say... 3000rpm @ 4psi as it would at 5500rpm at 0psi. So it would add fuel in the latter case, where it should not be adding fuel. With the MAP sensor, I set it to turn on at ~1.85v or so (or at least that's what I had LinuxRacr do...I think mine is set to that voltage), which the MAP sees as 1psi...at which point it starts using my extra injectors.

 

[Kooldino]

12 is not lean at 1 psi. It is very rich.

Truth

 

[Kooldino]

yeah 12:1 Vortech calibration.

This always creates confusion.

12:1 on the Votech is RICHER than 12:1 AFR, In my experience.

 

[Kooldino]

Nope..the easiest..way..is to live close to MPI Nick..(like i do)..and have him help/tune my car!

Until something goes awry and you don't know how to fix it yourself. (sick)