iracemine's purpose built N/A ST2 thread

The results are extremely relevant to my interests. :)
Hey thanks for following. As I watched the dyno results (mainly the vacuum readings) from the diffrent intake manifolds I am guessing on what I might need next. The stock mani with out the VI working (only short runners working), and having the "twiggys" AKA stage 3 N/A cams worked great up until 6K or so. Then the vacuum would spike up and down, just like ICE experienced. Then I got the VI working the long and the short runners, switching at 5250RPM. The vacuum reading would go crazy from 3500 to 5250 till the short runners would switch open, and calm back down until 6K again. I then put on 626 mani with even longer runners (yet nice and smooth with no bs to go through) and that made the vacuum spikes the worst yet so far.

My super lame theory is that short and fat runners might make this thing breath ok. yes... just ok. I know going to ITB's will liberate this motor, and changing stack lengths easy, but at a cost. A cost at the dyno w/tuner guy.

IF

you are running stock or J-spec cams you will most likely be loosing power by doing this IM shtuff. As you need to keep a nice velocity ramming a column of air into your tiny bit of scavenging effect mazda spec ed into the stock system. However with the amounts of air the stage 3 cams need I hope I can satisfy them with this cheaper solution than ITB's as I need to also get the brakes %100 and also pay for a few more races to keep my racing license current. THIS YEAR. and pay morgage, and bills and feed myself and pay for gas to get to work ect.. ect..
 
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Subin just found this thread. Was thinking of running itb's myself but then I realised how much work it is lol. Ended up settling for a supercharged setup that is still under construction lol
 

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I hope this works. If it does... it will save me a ton of money. Fit and finish where close, but rushed. If he could have just trimmed up the powder coat and re-taped the holes after welding the mani would have gone in a ton easier. Also the throttle cable sticks way up and seems dumb. But overall a excellent aftermarket piece. Waiting on a 45 degree elbow from summit and then should be off to the dyno.

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What are you doing to your manifold?

OK before I lay out 5k on ITB's I am going to try the 505 intake manifold. The runners are shorter than stock, MUCH shorter than the 626, but the angularity of the piece sucks, But I will like that I dont have to buy anything else and I can still use the ICV and my microtech.

Time to penny pinch and sell some crap and I can post up some dyno results for a N/A with a 505.
 
welp getting them to email me the dyno results is like pulling teeth. I might have to go back there and see if I can't wait around till a car has a problem and then jump on the computer and email my runs to my self. BUT... the vacuum spike are all but gone. The power curve is perfect for my application. approx 179whp, and 146wtrq. The torque curve is about flat as you can get. So the 505zoom intake will work great for the stage 3 n/a cams. I just need my dyno runs b4 I go and start posting up in the other threads.

Ordered dtc-60 brake pads and motol700. I will bleed this thing one last hard time and then change the pads and see if that will stop this monster. With all that I hope to be done. Just making videos would be the most custom making I want to do for a while.

Dyno results to follow.
 
Excellent numbers for a N/A car! What was the engine speed where 179 hp was made? I can't recall what you said redline was.
 
not at the rev limit. in fact it starts to level off around 6K. I am dying to get the runs from them, but like I said I will most liky have to go back down there and email them to myself. The last times they just printed them out, but I guess the system is no longer printing...
 
Where is your Microtech located, are you using the map hose that came with it?
Hey thanks for following. As I watched the dyno results (mainly the vacuum readings) from the diffrent intake manifolds I am guessing on what I might need next. The stock mani with out the VI working (only short runners working), and having the "twiggys" AKA stage 3 N/A cams worked great up until 6K or so. Then the vacuum would spike up and down, just like ICE experienced. Then I got the VI working the long and the short runners, switching at 5250RPM. The vacuum reading would go crazy from 3500 to 5250 till the short runners would switch open, and calm back down until 6K again. I then put on 626 mani with even longer runners (yet nice and smooth with no bs to go through) and that made the vacuum spikes the worst yet so far.

My super lame theory is that short and fat runners might make this thing breath ok. yes... just ok. I know going to ITB's will liberate this motor, and changing stack lengths easy, but at a cost. A cost at the dyno w/tuner guy.

IF

you are running stock or J-spec cams you will most likely be loosing power by doing this IM shtuff. As you need to keep a nice velocity ramming a column of air into your tiny bit of scavenging effect mazda spec ed into the stock system. However with the amounts of air the stage 3 cams need I hope I can satisfy them with this cheaper solution than ITB's as I need to also get the brakes %100 and also pay for a few more races to keep my racing license current. THIS YEAR. and pay morgage, and bills and feed myself and pay for gas to get to work ect.. ect..
 
Is that the map vacuum source off the plenum to the Microtech? If so when I dynoed my car the map was jumpin around badly up high, it was pulling from the plenum on my PG mani like yours.I ended up runnin a thicker 1/4" hose from my Vibrant vac block instead of the plenum,to the Microtech (my Microtech is close to where yours is. When I pulled the hose out of the firewall that came with the Microtech it was torn, thin,narrow,soft and weak. The new hose flattened out the map all the way up very smooth. Aaron at Pure Tuning who was doing the dyno knew what what wrong right off the bat,said the distance of the hose run called for a better vac source and bigger hose. Total difference in the wot and on road cruise, actually all the way around.
 
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I've got some self thought out upgrades goin on should add 10-15 hp N.A. to the 151 whp I posted. Any manifold made for the FS engine has way too long runners to make power above 6000,and that 505 is too short/way too big plenum/rectangle shape no good.No turbo manifold will do any widespread good on an NA FS motor . The ****** car was for sale no one wanted it, their loss now Im keeping it and taking it all the way. Its did it all myself - its mine!
 
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Well did not have enough time to find the better runs, but at least some proof of how much smoother the car ran with doing nothing but changing the intake manifold. And I mean nothing else. Not a air filter, spark plug, coil, vacuum tube, dick. Just the 505 zoom mani. You can see the massive spikes in this dyno sheet from last year was terrible, but the one from this year and the 626 mani I never even bothered posting cause it was so bad the car barely ran. Yes, way worse than this!

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And so ok, yes ITB's would be perfect in so many ways; tuning, breathing, rpm band, gains, blah blah blah. But the cost for me to do that would be more than I could get for the car, and well that would be/should be money spent on a van demon. BUT never the less I just kept thinking about the 505. Yeah yeah its a turbo mani, and its wrong in so many ways for n/a. But my motor is obviously starving for air. By looking at the air/fuel charts and the on and off of the stock variable runners you can tell the longer the runner the more starved the air. SO I thought the 505 zoom might work. I mean its already there. Its already made. And its a s*** ton cheaper then ITBs. So yes it was a gamble, but thick short runners seemed that it might do the trick.

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I will try to get the tuner to find the dyno runs with the higher numbers. I did stop by once and there was a 177 up on the screen so I know there in there. And maybe have him put the before and after on the same chart.
 

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That's a nice torque curve - only about a 20 ft-lb range from 2500-7000 RPM. Looks like you're making peak power right around 7000 RPM. Overall it looks to be a pretty good setup despite the intake manifold being "wrong in many ways."

A turbo intake manifold isn't necessarily bad for a N/A car. The principles behind the design are the same but turbo applications are more forgiving because you're shoving air into the engine. A well-designed N/A intake manifold will benefit a turbo car. If anything, runner length would need to be shortened slightly to achieve better top-end performance since the turbo will make up for the low-end velocity loss.
 
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This is so awesome. I want 180whp NA lol

Edit: I just noticed from the OP you are only running an OBX-style header?!?! Wow imagine how much more power you would be making with an AWR, Mazdaspeed, AutoExe, or Pacemaker.
 

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