Where should the MAF be installed? Before the turbo on the intake side or in the compression pipe near the intake manifold?


3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)

I believe right before the tb

Depends.... It can be in the intake side, or blow through.... Just needs to be calibrated accordingly. Also needs to be in straight section, away from bends.





P&P Tuning
420.5whp / 359.8wtq

I see, I have been doing some reading online and have found either or setups. I guess theres problems with using a BOV with the draw through type because the air has been measured already.


3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)

Nitrous Nate wrote:I see, I have been doing some reading online and have found either or setups. I guess theres problems with using a BOV with the draw through type because the air has been measured already.

on a draw through the BOV does not matter. On a blow through the BOV/MAF placement can cause issues......





P&P Tuning
420.5whp / 359.8wtq

QWK LN2 (needs an @ss whoopin) wrote:

Nitrous Nate wrote:I see, I have been doing some reading online and have found either or setups. I guess theres problems with using a BOV with the draw through type because the air has been measured already.

on a draw through the BOV does not matter. On a blow through the BOV/MAF placement can cause issues......

Draw through MAF setups that have the BOV vented to atmosphere can sometimes cause issues with metered air not being delivered to the engine, resulting in an overrich condition.
Blow through MAF are pretty foolproof so long as the BOV (if vented to atmosphere) is located upstream of the MAF.



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

Bill Hahn Jr. wrote:

QWK LN2 (needs an @ss whoopin) wrote:

Nitrous Nate wrote:I see, I have been doing some reading online and have found either or setups. I guess theres problems with using a BOV with the draw through type because the air has been measured already.

on a draw through the BOV does not matter. On a blow through the BOV/MAF placement can cause issues......

Draw through MAF setups that have the BOV vented to atmosphere can sometimes cause issues with metered air not being delivered to the engine, resulting in an overrich condition.
Blow through MAF are pretty foolproof so long as the BOV (if vented to atmosphere) is located upstream of the MAF.

Don't you also have the possibility of oil to contend with when using a blow through? That would seriously diminish the accuracy of the meter, cooling the element much faster, making your engine command more fuel than it truly needs. A draw through makes the most sense to me, anyways, because you don't have such large ambient temperature gradients and the corresponding large temperature deltas to account for compared to the compressor side. I do see the fuel issues with transient conditions activating the BOV, though.




I have no signiture

Whalesac wrote:

Bill Hahn Jr. wrote:

QWK LN2 (needs an @ss whoopin) wrote:

Nitrous Nate wrote:I see, I have been doing some reading online and have found either or setups. I guess theres problems with using a BOV with the draw through type because the air has been measured already.

on a draw through the BOV does not matter. On a blow through the BOV/MAF placement can cause issues......

Draw through MAF setups that have the BOV vented to atmosphere can sometimes cause issues with metered air not being delivered to the engine, resulting in an overrich condition.
Blow through MAF are pretty foolproof so long as the BOV (if vented to atmosphere) is located upstream of the MAF.

Don't you also have the possibility of oil to contend with when using a blow through? That would seriously diminish the accuracy of the meter, cooling the element much faster, making your engine command more fuel than it truly needs. A draw through makes the most sense to me, anyways, because you don't have such large ambient temperature gradients and the corresponding large temperature deltas to account for compared to the compressor side. I do see the fuel issues with transient conditions activating the BOV, though.

Yes, oil is a possibility with blow-through, but the MAF's are hardier and more resistant to it than you may have been led to believe. In our experience, it takes a copious amount of oil to affect them, typically only when there is some kind of problem adding excessive oil to the inlet tract. Further, in instances where the IAT (Intake Air Temperature) sensor is also housed within the MAF, this location has the additional benefit of being able to retard timing as needed to accomodate changes in intake temperature post-turbo and intercooler. A nice feature to have, especially in cars that see a large range of ambient temperature and/or boost conditions.

Draw through is preferred by most OEM's, but they also typically have recirculating BOV's and considerable validation resources.



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com

im running a blow through just before the throttle body and i have had no issues.

Who's got a MAF? I've got a MAP.



USACi =>146.9db
14.88 @ 90.73MPH =>GM Charger, Motor Mounts, Catback exhaust

2NVUS4U wrote:Who's got a MAF? I've got a MAP.

Someone with a 3400 swap?


1994 Saturn SL2 Home Coming Edition: backup car
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2NVUS4U wrote:Who's got a MAF? I've got a MAP.

I think he misspoke (mistyped?).



Bill Hahn Jr.
Hahn RaceCraft

World's Quickest and Fastest Street J-Bodies
Turbocharging GM FWD's since 1988
www.turbosystem.com