blow thru vs draw thru???

[Wnt2gofst]

Can some one explain the difference between the blow through and draw through cold air for the Vortech/Paxton kits? Which one is best or the even the pro's and cons of each.

I am almost ready to buy a supercharger and these kits seem to be very good just need get some details.

Also what is needed to mate them with the Boss intake?

 

[Full_Tilt]

Im curious about this as well.
Since its measure air mass it should be just as functional when used in either configuration, although Im sure the tuning would be quite different.

 

[Wnt2gofst]

Simple as blow threw is on the blowing side(after sc) of the SC and the draw is on the intake or(before sc)draw side of it?

 

[Full_Tilt]

Simple as blow threw is on the blowing side(after sc) of the SC and the draw is on the intake or(before sc)draw side of it?

Yes, thats what it means.
The obvious effect is that you have to recirculate the bypass/BOV with a draw through MAF.

Im curious if there are some more technical differences though.

 

[Wnt2gofst]

Yes, thats what it means.
The obvious effect is that you have to recirculate the bypass/BOV with a draw through MAF.

Im curious if there are some more technical differences though.

me too.

 

[five0three]

threw?




through

 

[Wnt2gofst]

threw?




through

Same Same people get the point or know what I was talking about.

 

[r.barn]

Draw through tends have to fewer voltage spike reading errors from poor sensor placement. Both work and blow through meters have a come a long way in solving their short falls.

Blow thru. usually only have issues if you put them too close to a pipe bend but you can put a BOV before the meter and not have to worry about recapturing the blow-off charge because it has not been metered yet. The draw air has metered that air so it must be recirculated back into the charge pipe just after the MAF and before the S/C.

 

[stang67gt]

I'm for blow through as the IAT sensor is built into the MAF and on boosted applications you always want to read what air intake temps are after the blower when possible (same reason why whipple and other pd blowers make you relocate the IAT sensor. With blow-through the MAF sensor is not 4-5 feet away from the throttle body which causes a delay in what is being sensed versus whats being ingested. If any of your intercooler pipes leak after the MAF will corrupt its calculation, a problem for both but usually there's 3-5 more connections with the potential to leak with draw-through versus the 1-2 after with blow-through (more of a concern for higher boost applications where popping boost tubes is a problem). And already mentioned that with draw-through you have to run a recirculation valve instead a vent-to-atmosphere blow off valve like with blow-through. With drawthough this can induce MAF backwash depending on the recirc valve placement. When you are boosting constantly can heat soak when you are always putting that hot compressed air back into the system.

The two downfalls that blow-through MAF's have are usually MAF placement and MAF range. With all the piping bending around stuff for room it becomes hard with some kits to find a nice straight piece of tubing for the MAF sensor to put in as you don't want to be reading turbulent air or air banking off a bend right before the sensor to give a poor signal. Another MAF placement consideration is that unless you extend the MAF wiring somehow you are limited to placement relative to the engine harness. There are kits that come with extensions or a MAFia for this purpose, but even the kits MAF placement is not optimal but convenient. The second consideration is that with blow through you are putting the MAF sensor into a smaller pipe than stock so your initial range is reduced and then you're pushing compressed air across it which takes up more range. The two fixes are getting a BA5000(HPX) MAF or getting a MAFia to increase the range. Another way is to increase the size of the tube that the MAF sits in but then you will have the same considerations as MAF placement but worse as resolution goes down as MAF tube size goes up, which means driveability goes down. Although a HPX or MAFia with also reduce resolution but not nearly to the same extent as a 4" MAF tube.

Hope this helps.

 

[Sky Render]

Blow through setups can have issues with turbulence if the BOV and pipe routing is not exact.

 

[chuck@evoperform]

@stang67gt

The Whipple and Roush kits actually utilize a 2nd IAT sensor and is enabled in the PCM through tuning. The Kenne Bell kits instruct you to relocate the IAT, but again if you have proper tuning support, you can wire it in in the same way as the Whipple and Roush kits and have both a before and after IAT reading just like the GT500's

 

[stang67gt]

@stang67gt

The Whipple and Roush kits actually utilize a 2nd IAT sensor and is enabled in the PCM through tuning. The Kenne Bell kits instruct you to relocate the IAT, but again if you have proper tuning support, you can wire it in in the same way as the Whipple and Roush kits and have both a before and after IAT reading just like the GT500's

Sorry I'm a little green on the 2011+ but good to know that the new processors have the ability of 2 IAT sensors (non-gt500).

I was implying more about the centrifugal superchargers rather than positive displacement as pd blowers are always draw through and don't run a large about of intercooler piping as the aftercooler is built into the lower intake.

 

[Wnt2gofst]

I'm for blow through as the IAT sensor is built into the MAF and on boosted applications you always want to read what air intake temps are after the blower when possible (same reason why whipple and other pd blowers make you relocate the IAT sensor. With blow-through the MAF sensor is not 4-5 feet away from the throttle body which causes a delay in what is being sensed versus whats being ingested. If any of your intercooler pipes leak after the MAF will corrupt its calculation, a problem for both but usually there's 3-5 more connections with the potential to leak with draw-through versus the 1-2 after with blow-through (more of a concern for higher boost applications where popping boost tubes is a problem). And already mentioned that with draw-through you have to run a recirculation valve instead a vent-to-atmosphere blow off valve like with blow-through. With drawthough this can induce MAF backwash depending on the recirc valve placement. When you are boosting constantly can heat soak when you are always putting that hot compressed air back into the system.

The two downfalls that blow-through MAF's have are usually MAF placement and MAF range. With all the piping bending around stuff for room it becomes hard with some kits to find a nice straight piece of tubing for the MAF sensor to put in as you don't want to be reading turbulent air or air banking off a bend right before the sensor to give a poor signal. Another MAF placement consideration is that unless you extend the MAF wiring somehow you are limited to placement relative to the engine harness. There are kits that come with extensions or a MAFia for this purpose, but even the kits MAF placement is not optimal but convenient. The second consideration is that with blow through you are putting the MAF sensor into a smaller pipe than stock so your initial range is reduced and then you're pushing compressed air across it which takes up more range. The two fixes are getting a BA5000(HPX) MAF or getting a MAFia to increase the range. Another way is to increase the size of the tube that the MAF sits in but then you will have the same considerations as MAF placement but worse as resolution goes down as MAF tube size goes up, which means driveability goes down. Although a HPX or MAFia with also reduce resolution but not nearly to the same extent as a 4" MAF tube.

Hope this helps.

Thanks very good info.

 

[08StangGT_CS]

Off topic but you're giving up on going NA?

 

[Wnt2gofst]

Off topic but you're giving up on going NA?

No not completely...I will run the car N/A with cams in it a few times then add the blower. The blower will not be for about a month or so after I get back.

 

[chuck@evoperform]

No not completely...I will run the car N/A with cams in it a few times then add the blower. The blower will not be for about a month or so after I get back.

You do realize that N/A cams and blower cams and turbo cams are all different grinds right?

 

[Wnt2gofst]

You do realize that N/A cams and blower cams and turbo cams are all different grinds right?

Yes. That is another issue I am addressing now.


More then likely then factory cams will be reground.

 

[assasinator]

i setup my cars with blow through. i make sure the piping matches the maf size for at least 12-18" and there are no tuning issues. there seems to be maf turbulence issues more often with draw through from pulsing coming from the power adder.

its a packaging preference. centri's and turbos are the only choices. all PD's are drawthrough.

ive never tried it, but im sure the maf could be placed far enough from the power adder to minimize it. -drawthrough.

Sorry I'm a little green on the 2011+ but good to know that the new processors have the ability of 2 IAT sensors (non-gt500).

I was implying more about the centrifugal superchargers rather than positive displacement as pd blowers are always draw through and don't run a large about of intercooler piping as the aftercooler is built into the lower intake.

in spite of comments, blow through is easier to get a pure maf signal. just run a straight pipe to it, and avoid sizing changes just before or after the maf.

 

[beefcake]

I am running draw through and the setup works great With my 135mm maf on the 2011, i went from 9 to 13 to 16 psi on the ttrim, and with my lund tune, not one thing needed to be changed!!!



computer kept a perfect lambda every time

 

[SD07GT]

I am running draw through and the setup works great With my 135mm maf on the 2011, i went from 9 to 13 to 16 psi on the ttrim, and with my lund tune, not one thing needed to be changed!!!



computer kept a perfect lambda every time

I like your style (lol) All this blow through and moving you IAT sensor is a fad !

I run up to 20 psi on a Draw through and never moved an Iat sensor in my life ...The sky is falling Many top tuners around the country still prefere a Draw through.