MAF sensor

[motorhead]

In the past 15 years or more, we have seen many examples of 12 second cars running an aftermarket system combined with owners that have no clue as to how to tune it but it makes for good conversation at Sonic or Tim Horton's.

Ouch.

[reality]

 So at what point does a 3in become a restriction? Mid 10's?
Something I'm missing here.

[Scoobum]

Steve...did Grumpy not crack the 9's on a 3 inch setup? LSI MAF and a 3 inch pipe? I'm fairly certain he did.

[Steve Wood]

yes, you are.

It's always a restriction.  The question is a what point does it become significant and that is not only dependent upon ones combination but, also how far one tries to push it toward it's theoretical limit without going down hill.  The turbo is an air pump...pumps are capacity limited by the intake size as well as the outlet size.

[TexasT]

At what point does a 3in inlet become a restriction.
If I change my 3in inlet to a 4in mafless S.Y. how much will I pick up.

If you hit the old KenneBell catalog, a tenth of a second and one mile per hour. Or at least that is what they touted most of their products. If you added them all up you were in the sixes..

Is there an SD how to? I'm guessing you don't need a powerlogger as this was out before the powerlogger came along I think. I really shouldn't take on more but I think it is the challenge. Probably should just order the basic translator from full throttle and keep moving forward. I will say, having a scan master and being able to goof with the 5.6 chip hasn't gotten me to do any tuning . But I haven't been to the track either.

I'm just hoping to learn some power logging skills from Jim and Jason as they learn.

[reality]

 Now we are going around in circles. IS it a restriction or not a restriction and how much would you pick-up going from 3in to 4in if it is?

[Scoobum]

Correct me if I'm wrong...but a given engine can only 'swallow' a certain amount of air.

[Steve Wood]

yes, the instructions are on line...but you do need a PL   Here are the instructions   https://docs.google.com/viewer?url=http%3A%2F%2Fwww.turbotweak.com%2Fturbotweaksds.pdf

That's for the SD or as I called it, SD1

I believe you can operate the SD2 as if it is an SD1 if you wish to begin that way and get things close before worrying about AF tables, etc.

[Steve Wood]

Correct me if I'm wrong...but a given engine can only 'swallow' a certain amount of air.

Basically, you are wrong

You can compute the cfm of an engine, but what is important is how dense that air is...in other words how many air molecules you put into the engine and that depends on the air density coming out of the air pump and it's size

That's the beauty of forced aspiration.  There is a practical limit, however, in that we can reach a point where the mechanical structure of the engine can no longer contain the combustion pressure and things expand

[Steve Wood]

Now we are going around in circles. IS it a restriction or not a restriction and how much would you pick-up going from 3in to 4in if it is?

No, you are going in circles....I said it was always a restriction, just as the air filter is a restriction.  At what point does it become a significant restriction that is costing some power.

I would say that depends upon the total combination and the tune applied which affects the point where the turbo starts leaving the zone of maximum efficiency on the high side.

Now, if you had bothered to read Bison's post that I quoted above, he gave you a combination and gave you some dyno numbers for that particular car.

[Scoobum]

I over expanded an engine once...didn't like it. NASA is still looking for my head gaskets with the Hubble and I twisted a head into a pretzel.

[Steve Wood]

LOL....NASA is government funded, those hgs are gone forever

[Steve Wood]

Brad, take the HP rating of the 6262 and compute the cfm.  Joe Lubrant, when he was the turbo guy at PTE said the hp was calculated by multiplying cfm by  0.69.

Compare that to the cfm of the engine at the rpm you shift at.

[TexasT]

Now we are going around in circles. IS it a restriction or not a restriction and how much would you pick-up going from 3in to 4in if it is?

It is all a restriction, intake, turbo, intercooler, intake, heads, exhaust. As with any fluid, the volume, rate of travel, characteristic s of the fluid all change the amount that each of those things restrict. If you have a street car like mine with a stock turbo or a ta49 or other small turbo, I doubt you notice too much on the time slip. Just like a loose converter changes the way the car "feels", getting more air and fuel in quicker makes or enables the engine to rev quicker. Temp as Steve noted makes a big difference in just how dense that intake air is. More air in, the more fuel you van put with it and more power can be made. You know how much better your car runs on a cool evening than on a hot summer afternoon at the track.

[Steve Wood]

Rich, I think Indy was a lot more interesting when the cars topped out between 160-180....now it looks like slot car racing to me.  Also, there used to be more disparity in the cars, it seems