dmyers151 Posted March 2, 2009 Report Share Posted March 2, 2009 Not sure if this belongs here, but its a mod of sorts, so here goes. I've been meaning to rebuild my TB and clean it up since it looked like it had leaked in the past and was covered in a layer of brown sticky garbage. So yesterday I decided to take the plunge and rebuild the spare I had so as to keep the car intact during the process. Well, while I was cleaning up the parts, I noticed that the casting mold for the mixing bowl had left a rather healthy parting line on the inside as well as some burrs and ruff edges. So, I had at it with my trusty dremel, and here's what I came out with: http://i471.photobucket.com/albums/rr71/dmyers151/0228091557.jpg If you've ever examined the inside of the mixing bowl, you'd notice there are two somewhat large (~.100") steps as the intake enters the bowl itself, as well as parting line marks on either wall, and burrs around the injector bores. I cleaned up the burrs, took out the parting lines, and smoothed the steps out for a clean transition into the chamber. Once that was all taken care of, I used a little scotch brite wheel attachment and polished the whole thing, inside and out. I also smoothed out the edges on the throttle plate where it meets the mixing bowl. The car seems more responsive with this little mod, but I also replaced the injectors with the Delphi 65/95 setup and did the clips so it could be there as well... What do you pros think, would this make a difference at all? I really only did it because I had some time on my hands and it probably couldn't hurt. Link to comment Share on other sites More sharing options...
CondorTSI Posted March 2, 2009 Report Share Posted March 2, 2009 Looks like you had some time on your hands. Any reason for you to keep the air divider? Any real gains by keeping it in their even after you polished it out like that? Either way I think you did yourself and your car a big favor. Good Job Link to comment Share on other sites More sharing options...
dmyers151 Posted March 2, 2009 Author Report Share Posted March 2, 2009 I've heard removing the divider increases intake turbulence and will screw with your idle, so I left it for now. If I come across another mixing bowl, I might just take that divider out and see how the car reacts. Link to comment Share on other sites More sharing options...
strang3majik Posted March 2, 2009 Report Share Posted March 2, 2009 how does it idle? and how are those injectors working for you Link to comment Share on other sites More sharing options...
dmyers151 Posted March 2, 2009 Author Report Share Posted March 2, 2009 Idles really smooth, and the injectors are great, I ment to PM you. I had one problem with the FPR, I guess it went bad and it was actually being bypassed and blowing fuel into the mixing bowl through the vacuum line. Luckily, I had a spare and it all worked out. Link to comment Share on other sites More sharing options...
89PalermoSHP Posted March 2, 2009 Report Share Posted March 2, 2009 the mixer is looking good. follow up with some sand paper http://i177.photobucket.com/albums/w202/89PalermoSHP/mixer.jpg Link to comment Share on other sites More sharing options...
Coke Posted March 2, 2009 Report Share Posted March 2, 2009 Oooooooo shiney objects! Looks good Dale...I might just send you mine Hahaha Link to comment Share on other sites More sharing options...
strang3majik Posted March 2, 2009 Report Share Posted March 2, 2009 the mixer is looking good. follow up with some sand paper http://i177.photobucket.com/albums/w202/89PalermoSHP/mixer.jpg if mine ever looked like that, Id be afraid to put it on...it may get dirty...lol Link to comment Share on other sites More sharing options...
89PalermoSHP Posted March 2, 2009 Report Share Posted March 2, 2009 it was a bit obsessive for me i still have work to do on it. unfortunatly it doesnt match my intake on the outside of it Link to comment Share on other sites More sharing options...
Coke Posted March 2, 2009 Report Share Posted March 2, 2009 Do you use Mothers on it? LOL Link to comment Share on other sites More sharing options...
89PalermoSHP Posted March 2, 2009 Report Share Posted March 2, 2009 if your gonna do it at all, do it right Link to comment Share on other sites More sharing options...
Indiana Posted March 2, 2009 Report Share Posted March 2, 2009 You look at the way the divider is placed then you look at the primary and secondary injector placement. If the air were swirling would it mix as well? Like you said the divider is to straighten out the air flow just prior to mixing in the fuel. This is sort of why they named it the injection mixer. Remove that divider and have injectors that spray poorly and what do you suppose can happen? I leads to crazy thoughts like the intake flows like crap. You have conclusions based on observing only the end result and the details are usually overlooked. Like buying check valves because your dipstick doesn't pop out any longer and you hear some sucking sound at idle but that is oh so not what is going on... Glad you kept that divider in there, it helps that air/fuel mix divide more evenly after it goes through the throttleplate as well. Link to comment Share on other sites More sharing options...
dmyers151 Posted March 2, 2009 Author Report Share Posted March 2, 2009 Gotcha Indiana, I was waiting for you to chime in with a comment. I knew I read somewhere that it was bad to remove it. Justin, if you want to send yours to me I'd be more than happy to do it up just like mine. Now that I've done one, a second should be no problem and go much quicker. Lemme know. Link to comment Share on other sites More sharing options...
Maxzillian Posted March 3, 2009 Report Share Posted March 3, 2009 Actually if the divider was made to straighten the air, it would not have a blunt backside like the factory mixer does. Instead it would be knife edged end to end. Instead it induces eddy currents (sort of like a concentrated turbulence) that trails behind the divider and into the path of the injectors. These eddy currents do a great job of dispersing the fuel and mixing it with the air, leading to better combustion. Link to comment Share on other sites More sharing options...
Technology Posted March 3, 2009 Report Share Posted March 3, 2009 Put a turbonator in there. Link to comment Share on other sites More sharing options...
89PalermoSHP Posted March 3, 2009 Report Share Posted March 3, 2009 Put a turbonator in there. isnt that veird Link to comment Share on other sites More sharing options...
MontyTSI Posted March 3, 2009 Report Share Posted March 3, 2009 I've heard removing the divider increases intake turbulence and will screw with your idle, so I left it for now. If I come across another mixing bowl, I might just take that divider out and see how the car reacts. I dont have any scientific data to confirm this.. but that divider is directly inline of the outlet nozzels of the injectors. So as the boost/ cfm (velocity) increase if the divider is not there the fuel load from the injectors is smashed against the back wall of the mixer housing. It would appear this could cause an uneven fuel mix which for a TB car is not so good as the stock intake already causes an imbalance of fuel density b/t 1-4 and 2-3 Link to comment Share on other sites More sharing options...
natturbo2.6 Posted March 4, 2009 Report Share Posted March 4, 2009 sweet i will try this on a spare i have in the trunk. thanks for the little tip there buddy. Link to comment Share on other sites More sharing options...
89PalermoSHP Posted March 6, 2009 Report Share Posted March 6, 2009 this isnt 100% but i think it where Im going to leave it. http://i177.photobucket.com/albums/w202/89PalermoSHP/mixer2.jpg http://i177.photobucket.com/albums/w202/89PalermoSHP/mixer1.jpg Link to comment Share on other sites More sharing options...
eurotiva Posted March 6, 2009 Report Share Posted March 6, 2009 Nice man. Do you feel like doing my wheels? lol Link to comment Share on other sites More sharing options...
dmyers151 Posted March 6, 2009 Author Report Share Posted March 6, 2009 this isnt 100% but i think it where Im going to leave it. http://i177.photobucket.com/albums/w202/89PalermoSHP/mixer2.jpg http://i177.photobucket.com/albums/w202/89PalermoSHP/mixer1.jpg That looks ridiculous. It kinda looks to me like you left the step on either side of the divider, maybe it's just the reflection. Either way, yours looks considerably more polished than mine. Great job. :thumbsup: Link to comment Share on other sites More sharing options...
89PalermoSHP Posted March 6, 2009 Report Share Posted March 6, 2009 Yea... theres just a bit of a web coming off the divider. I could get obsessive about it for another week but I think it will be fine. Its probably not any huge gain (15HP max ) but it is the bottleneck of the intake so why not make it as smooth as you can. Ill get a pic of my timing cover, I did the same with the water pump cavity :thumbsup: Link to comment Share on other sites More sharing options...
Briman2021 Posted March 26, 2009 Report Share Posted March 26, 2009 To the people going for a mirror finish, have you read anything about giving the intae surfaces a rougher textures to promote turbulence to keep the air/fuel mixed better? I remember when I was reading up on how to do it, everyone said to leave a little roughness on the intake, and as smooth as possible with the exhaust, has this been proven/disproven? example: http://www.bonnevilleforum.com/t267503/ Link to comment Share on other sites More sharing options...
dmyers151 Posted March 26, 2009 Author Report Share Posted March 26, 2009 I just posted a response to a similar question not too long ago. I think that what your asking is a common argument among performance enthusiasts. Rougher walls induce turbulence and thus better mixing, while a smooth intake wall will increase intake velocity. I have no idea which is better, but I know that taking down the parting lines and whatnot that are in the mixing bowl are definitely an improvement. It's such a small area anyways, I cannot really see what myself or 89Palermo did to be that beneficial or detrimental, it's kinda more just to say it's done. Link to comment Share on other sites More sharing options...
Drive-By Posted February 6, 2010 Report Share Posted February 6, 2010 Absolutely right the divider is for vortecy creation just like the MAF divider but for obviously diferent reasons. I side with polished over rough as fluid dynamics would sudjest a rough surface at high velocity narrows the port by average of twice the hieght of the protrusions. Nice work I will be doin Liv's when I replace her seals. Link to comment Share on other sites More sharing options...
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