fredrik94087 Posted March 7, 2015 Share Posted March 7, 2015 It started with a desire to have a larger TB. The OEM TB was not going to be an easy job. Throttlehappy suggested the boomba TB for STI. The boomba TB has a 75mm opening. However, at the Intake Manifold, it necks down to 65mm (same as OEM). The intake manifold is 68mm. So, I had the back plate of the boomba TB machined to 68mm and I had the back plate mounting holes slotted to fit the larger bolt pattern of the 3.6R intake manifold. This still allowed the gasket of the boomba back plate to remain in place. I followed their startup instructions. Started the car...no codes/faults. Let it idle a bit. Gingerly went around the block. No issues thus far. I couldn't log anything because I am useless with torque pro and my laptop had completely discharged. I don't believe I am going to cause any damage by going from 65mm to 68mm. I am re-charging my laptop and will log either later today or tomorrow. Heading for a short drive to the grocery store...fingers crossed. 20150319 update: I was datalogging and decided to compare mass airflow (grams/s) at similar/same engine speed at WOT as before and after. Before: 5451 = 205.88 5725 = 211.73 5993 = 215.75 6151 = 219.49 6294 = 222.45 After: 5488 = 209.88 5727 = 221,65 5962 = 222.91 6014 = 224.95 6283 = 229.58 I had to combine this data from a few different logs as it is difficult to capture every single rev at WOT. I hope this helps. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
Perscitus Posted March 7, 2015 Share Posted March 7, 2015 Awesome awesome awesome. Let us know how Shrek likes his bigger mouth. Throttle response should be much improved! Link to comment Share on other sites More sharing options...
GTEASER Posted March 7, 2015 Share Posted March 7, 2015 Nice job Fred! Who would have thought that teaching you how to do your own brakes would lead to this! GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 7, 2015 Author Share Posted March 7, 2015 Much appreciated gteaser...and it made life a lot simpler for track days. The koni thing I did was a more painful ordeal maybe becuse of the errors more than the trials. This one was pretty straight forward. Maybe I got lucky. Quick update... I cant seem to get any codes or knock (that I can hear) under WOT. Going from 65mm to 68mm is about 9.5% increase in surface area. Assuming air goes up 9.5% from the 12.5 ratio Rob had tuned, I would be around 13+. Laptop is not charging. Either my new battery will work or I have to do something else. Initial impression...biggest impression is that the car pulls a little better in third. Cant dyno as the local shop has closed and I dont want to deal with mann just yet. I dont know if they want to deal with me either. I will figure out my logging problems and keep you guys posted. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
Perscitus Posted March 8, 2015 Share Posted March 8, 2015 Sounds good Fred. Is the Boomba unti 70 or 75mm? I think as long as the butterfly valve is 75mm, the TB can be considered 75mm, even if its 65 or 68mm on the inlet and outlet ends. Or 75mm on the inlet and 68mm on the intake manifold facing outlet. In fact its very good that the ID is not the same throughout, otherwise we'd be dealing with a rather big velocity loss vs stock. The 75-68 helps recover some of the stock venturi effect we have going on to help fill the manifold and carry some turbulence into the cylinders. Did you notice snappier or crisper throttle response? Especially evident going from cruising speed to WOT or rolling start WOT? That should be there, like the acceleration in 3rd you sensed. Gains are likely a function of a re-tune. If the engine can benefit from and is seeing more air now, then fuel adjustments will nicely balance things out and bring out the hp/tq. I think you will pickup some power with this mod. Can't wait! Link to comment Share on other sites More sharing options...
ripstik Posted March 8, 2015 Share Posted March 8, 2015 Glad to see you got it done Fred. can't wait to see what happens after a tune. Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 8, 2015 Author Share Posted March 8, 2015 It is 75mm perscitus. I just checked their web. So 75 to 68 neck down. The butterfly is on the 75mm. The backplate necks down. Thats what made it super easy to go from 65 to 68. Third gear pulled easier. Seems like the car may have picked up a little on the top end. Wont know for sure until I either get on same dyno or until I see my straightaway speed at Laguna. New battery did the trick. I managed to do some logs. I will upload and send to Rob. Do you guys care for me to post any logs? "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
Perscitus Posted March 8, 2015 Share Posted March 8, 2015 Oui, oui. I'd love to see peak MAF readings in either g/sec or CFMs under WOT and measured AFRs under WOT and warm idle. Plus short and long term fuel trims. Rob was excited to get cracking on the logs and a retune. Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 8, 2015 Author Share Posted March 8, 2015 Looks like AFR is getting to 11.5??? I believe the column called "AM" is my AFR reading. At cruising, it is hovering 14-16. The smaller files are WOT. The two larger files are cruising.DeltaLog-ad09c-1704-Sat Mar 7 2015 17-03.32.csvDeltaLog-ad09c-1704-Sat Mar 7 2015 17-16.57.csvDeltaLog-ad09c-1704-Sat Mar 7 2015 17-11.17.csvDeltaLog-ad09c-1704-Sat Mar 7 2015 17-11.58.csvDeltaLog-ad09c-1704-Sat Mar 7 2015 17-15.43.csvDeltaLog-ad09c-1704-Sat Mar 7 2015 17-16.26.csv "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 9, 2015 Author Share Posted March 9, 2015 I updated my previous post. It hit me in the shower. My statements and assumptions were correct, but my math was off. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 9, 2015 Author Share Posted March 9, 2015 Spoke with Rob. He says the car is happy and amazingly the car compensated and ran a bit more rich. He will get me an updated tune along with something additional they have been developing in house. Cant wait. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
GTEASER Posted March 9, 2015 Share Posted March 9, 2015 along with something additional they have been developing in house. Oooh, oooh! What is it? GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
GipsySpec.B Posted March 9, 2015 Share Posted March 9, 2015 This is all very cool to read up on. Nice work Fred and once I get out that way I'll definitely join you at Laguna with the Spec.B Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 9, 2015 Author Share Posted March 9, 2015 Oooh, oooh! What is it? Lets say it has a little to do with the transmission. It is not finalized, but we will keep working on it. This is all very cool to read up on. Nice work Fred and once I get out that way I'll definitely join you at Laguna with the Spec.B Thanks Gipsy. It's not that easy to squeeze blood out of a turnip, but we are trying. Once I get my tune, I will take care of brakes and tires and I should be good to go. Oh yeah, forgot about coordinating with the wife before hand "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 19, 2015 Author Share Posted March 19, 2015 first post updated.... 20150319 update: I was datalogging and decided to compare mass airflow (grams/s) at similar/same engine speed at WOT as before and after. Before: 5451 = 205.88 5725 = 211.73 5993 = 215.75 6151 = 219.49 6294 = 222.45 After: 5488 = 209.88 5727 = 221,65 5962 = 222.91 6014 = 224.95 6283 = 229.58 "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
GTEASER Posted March 20, 2015 Share Posted March 20, 2015 2-5% increase. I think that engine is just not capable of sucking any more air. What is the rate of airflow that a 3.6l 6cylinder with your compression ratio at said rpm process? My guess is that you aren't gonna get any more air into it without forced induction. GTEASER's 2012 Legacy GT - Sold GTEASER's 2009 XTeaser - Sold GTEASER's 1992 Legacy SS - Sold Link to comment Share on other sites More sharing options...
fredrik94087 Posted March 20, 2015 Author Share Posted March 20, 2015 That is most likely a true statement, GTEASER. I increased the surface area by 9.4%, but gained only 2 to 3% in airflow. But, I have not looked into port matching the cylinder heads to the intake manifold. This would be costly, but if there is a mis-match as there was with the TB opening and the IM opening (65mm vs 68mm), that is something that can be addressed. If the IM opening is larger than the cylinder head, then there may be an improvement that can be made...but costly at that. If I can get on that darn dyno next week or even the week after (assuming everything falls into place with the next door shop taking it over), I would be happy if I see a 2-3% WHP and WTQ gain. However, that may not happen in a linear fashion. Increase TB by 9.4% results in 2-3% more airflow and ???% HP gain (maybe 1%???) I have to get on that dyno. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
marsho Posted August 26, 2015 Share Posted August 26, 2015 Was this ever dyno'd? tuned? any CEL's? Endless thanks for tinkering, there's so little that can be done to these cars for gains without throwing away $5k for a supercharger. kudos. Link to comment Share on other sites More sharing options...
fredrik94087 Posted August 26, 2015 Author Share Posted August 26, 2015 Was this ever dyno'd? tuned? any CEL's? Endless thanks for tinkering, there's so little that can be done to these cars for gains without throwing away $5k for a supercharger. kudos. Nope...never got a chance to dyno it...complicated situation with dyno availability. I had to use the same dyno or would not know if I gained or lost. I can tell you that ItalianLegacy has the TB now. They were able to tune for more power as they had better flow. No cel. No issues. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
marsho Posted August 26, 2015 Share Posted August 26, 2015 Bummer. Yea but his is charged, meh I'll still see if he added it to his build tho... No cels or issues? Bravo I'd mark this as a win then. Score one for the EZ36! Link to comment Share on other sites More sharing options...
Texas_Legacy Posted April 20, 2017 Share Posted April 20, 2017 What is the Boomba TB part number? They have several listed on their site and I am not sure which one was used for this. Thanks! Link to comment Share on other sites More sharing options...
fredrik94087 Posted April 21, 2017 Author Share Posted April 21, 2017 I assume any 2008 or newer STI TB would be the same??? Remember that you need to have the plate machined for our wider bolt pattern. "It's within spec" - SOA "Depth is only shallowness viewed from the side." - Fredism "So, how much did it cost for your car to be undriveable ." - Stephen (very close friend) "You have done so much it would be stupid to go back." - Sunny of Guru Electronics 2018Q50RS | 2015WrxThread | Shrek Link to comment Share on other sites More sharing options...
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