Cheap maf mod

Nolimit1112

Registered User
I was bored at work to day so I decided to remove my MAF and bore it out on our lathe. I'm not sure what the stock bore is but after epoxying up the outsides because I knew I was going to bore holes through it when I opened it up. I ended up with 62MM bore on a stock maf. Also opened up the sampling tube to 0.455 to compensate for the bigger bore. Seems to have help torque down low and a small boost gain in the high rpms. Good mod for 10 bucks worth of epoxy and 10 minutes on a lathe.
 
I'm sure the tune is off some now but it absolutely has more power now. Not a huge gain but for the low cost and ease of what I did it runs better. Gonna upgrade everything soon just want to get what little gains I can until I do the whole induction and fuel system.
 
Sounds like a great mod! I need some extra POWAH how much to make me one of these custom mafs??
 
You just destroyed your MAFis what you did. Any power increase you are feeling is likely due to running lean. If you want a cheap MAF upgrade, go get one out of a 4.6l tbird or cougar in the junkyard. They are 70mm from the factory, and the transfer functions will be much closer than something that was just bored and drilled out.
 
I agree, the Maf is off now and probably running lean. Might feel like an improvement untill you go boom. I dont think cheap mods are always bad but one that governs your fuel to air ratio isnt where you want to be cheap

Ken
 
Hooked up my wide band today to keep an eye on AFR and its not dead on but who is to say any stocker with 120K is perfect. However it isn't running lean. Its still a little rich.
 
Damn it picked up that horsepower and tq that much and its that rich!? I deff need to do this.. If tou lean it out it may do a wheelie! Any pics on how i can do this?
 
Exactly. OP, you realize that the EEC relies on the MAF to determine Load, and thereby Spark, right? And that 12.4:1 isn't what most would consider "rich"?
 
I have built several turbo bikes and run 10 psi on stock engine 10:1 compression with afr at 13.5. I don't see the pripoblem.
 
I have built several turbo bikes and run 10 psi on stock engine 10:1 compression with afr at 13.5. I don't see the pripoblem.

The SC AFR is considered "Safe" at 11.5. It is not a NA engine, but a forced induction.

It will run with that AFR, but it is not safe. It is that simple. If that is not agreeable that is fine, but the people on this board have the experience.
 
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I have built several turbo bikes and run 10 psi on stock engine 10:1 compression with afr at 13.5. I don't see the pripoblem.

At 13.5 AFR an SC motor will live. At 12.5 AFR it probably won't. Factory setting is 11.0, we tend to run 11.5-11.8.

There is an immense difference between a bike motor and an SC motor.
 
Let me get this straight Factory is 11 and it will live at 13.5. With 12.4 being in the middle why will that kill it? Yeah difference in the bike is a lot weaker internals and a lot more RPM's. The bike motor is a time bomb waiting to explode stock compared to the 3.8 AFR is AFR regardless of what forced induction gas engine its in. 12.5 or lower at full boost/wot seems to be in a safe range.
 
I think David miss spoke on the 13.5. Think he meant won't live.

But the bike motor has a fraction of the weight to carry.

And the 94-95 cars command 9.5:1 at high load/rpm
 
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