blow Vs Pull through pros and cons

seabeebuggy · Post by **seabeebuggy** » Mon Jul 24, 2006 6:46 pm

I have seen here people talk about both set up. it seams to me the pull through is easy-er to set up. as there is no need for a enrichment system like a blow through. but it seams to my a blow through will make more power. as you can cool the air. both can have water injection. but it seams blow through is the way to go for the most power. yes ? no?

MinamiKotaro · Post by **MinamiKotaro** » Tue Jul 25, 2006 3:59 am

Fuel injection is the only way to go. Scrap the distributor while you're at it and get a wasted spark or coil-on-plug system.

seabeebuggy · Post by **seabeebuggy** » Tue Jul 25, 2006 7:57 am

I was asking in general , what people think about the 2 set ups . not about mine. I just dumped 800$ into a mallory set up. It will be there for a while..

I was just trying to get some people talking here.

fl_buggy · Post by **fl_buggy** » Tue Jul 25, 2006 8:16 am

All else being equal, a blow-thru will make more power because any restriction before the turbo really jacks up the pressure ratio of the compressor. Obviously the carb before the turbo is a sizable restriction.

But I feel draw thru is easier to tune because the carburetor acts as normal. Setting aside the setup of a carb for blow thru, its different to tune than a carb that only sees atmospheric pressure.

Draw thru is also a bit cheaper and easier to setup the fuel supply. You don't need a rising rate regulator or higher pressure pump for draw thru. These are pretty minor things but can add up to a generally easier setup.

madpballer · Post by **madpballer** » Tue Jul 25, 2006 7:41 pm

well all th fastest bugs i have seen have been a draw through carb system, or a blow through fuel injection. ive never seen a ms go faster then 12.5 or never heard of one. i know many people have fuelleakage problems on blow through system anything past 15 lbs even when prepped corectly. i beilieve that a draw through system would be better for making power at the track. but a draw thoguh might be a lil more driveable. mostly its breference i guess

seabeebuggy · Post by **seabeebuggy** » Tue Jul 25, 2006 7:53 pm

How does a draw through go to higher boost levels when you cant cool the air? or can you? keeping it all carb set ups no EFI. I can see EFI making more power . If you cant charge cool then to get higher boost levels in a draw through you must use water injection and or ??? I like the look of blow through but it would have been much better i think to go draw through. but for street use , can you get higher boost levels out of it on super unleaded? or go to race gas? see my point. I don't know if it is a correct point.

madpballer · Post by **madpballer** » Tue Jul 25, 2006 8:07 pm

kinda lost me. personally i would for sure use water injection over an intercooler every time.. on average an intercooler will drop your boost about 2 lbs (generally). plus they are big and bulky and half the time are heat soaked on a bug anyway. idk just my thoughts.

seabeebuggy · Post by **seabeebuggy** » Tue Jul 25, 2006 8:19 pm

I was all over there wasn't I.
I have both water and a intercooler on my buggy. electric fan to keep the cooler cool. It is a small cooler . I would be shocked if I lost boost. it is about filling volume. maybe it will just take a second longer to get to same boost levels.

madpballer · Post by **madpballer** » Tue Jul 25, 2006 8:27 pm

i guess it all depens on what kind of turbo on what motor. i was told buy a highly repeutable turbo shop that an intercooler generally lowers boost and creates more lag. i think it all comes down to preference again.

seabeebuggy · Post by **seabeebuggy** » Tue Jul 25, 2006 8:45 pm

I am sure there are some affects . on the big coolers more so. I would just have to turn the boost up I guess. I don't know how high it will go yet. i hit 17lbs once and i let off the gas when it happened. i run at 12 lbs. but 15 sounds good. I hope to make it on pump gas. with the water/ methanol mix and cooler.

madpballer · Post by **madpballer** » Tue Jul 25, 2006 9:04 pm

what water injection kit you running

Marty · Post by **Marty** » Tue Jul 25, 2006 9:44 pm

Are you talking street or drag or just max power?

poop de oiad · Post by **poop de oiad** » Tue Jul 25, 2006 9:54 pm

Theoretically, with the same boost level, an draw through setup will make more power than a non-intercooled carbed blow through(and possibly fi) due to the cooling effect of the mixture. Not much cooling, but it's definatly there. How does a draw-through run high boost levels w/o cooling? Race petrol.
I have heard opposing arguements over whether or not one loses some boost with an intercooler. I do'nt know about that, but there will be more lag after shifting(especially with a blow off valve). Honestly, I think air-air intercoolers are'nt the best idea for an acvw anyway. Look at how big aftermarket ic's get for porsche 930's and the air-water setups still blow them away. For a blow through, air-water is the way to go.
Add to draw through cons: cold starting and the necessity to keep on tapping the throttle while idling to clear the puddled petrol before the compressor. It's all up to you to decide. Me personally, I like the old fashioned low compression 4bbl d-t approach. I'll take the quintessential on/off turbo feeling to the tiny turbo, "feels like a big n/a", feeling anyday. Maybe not ideal, but it was enough to suprise that s2000 from a highway roll last night!

seabeebuggy · Post by **seabeebuggy** » Tue Jul 25, 2006 9:59 pm

I have a coolmist set up.
I was just talking in general street driving max power. it would have to be able to be driven.

seabeebuggy · Post by **seabeebuggy** » Tue Jul 25, 2006 10:06 pm

poop de oiad wrote:Theoretically, with the same boost level, an draw through setup will make more power than a non-intercooled carbed blow through(and possibly fi) due to the cooling effect of the mixture. Not much cooling, but it's definatly there. How does a draw-through run high boost levels w/o cooling? Race petrol.
!

I was thinking of regular petrol fuel not race gas, you can add what ever aftermarket stuff you like. both carb set ups.

the only reason I ask this is i see people say draw through is the better set up for power . I was thinking you can get more power with a blow through due to the extra cooling you can add to it. both can use all other things like water injection race fuel etc.