rxseven

Just get rid of them! According to Dave Lemon of mazdatrix, his dyno testing showed maximum power without any kind of sleeves more than even the radiused ones you could get from pineapple. As for low end torque, it will get a bit more sluggish under 2800 rpm. Since it is hard to keep the car under 2000 rpm anyway, it is a loss over a very narrow range. This has been my observation on both my N/As.

pengaru

I've suspected something like this, but I imagine radiusing the 5th and 6th ports in the housings is better than just ditching sleeves (this is done in the popular turrentine overhaul video)... the pineapple inserts still keep the sleeve so the passage is limited by the sleeve, you cant really port it or match it to the LIM well. Is Dave Lemon's statement you mentioned available on the web? If so, URL?

FCmaniac

Here, $10



http://cgi.ebay.com/ebaymotors/ws/eBayISAP...item=1872501557

mazdaspeed7

I completely disagree with you. First, I have been there, and done that. I ran my car without the sleeves for a while. The car was on its face below 5K rpm. I have never driven a car with worse low end. It was aweful. Then I took and made an insert to go into the runner for the 5/6 ports that made it a nice smooth transition into the ports, kinda like the pineapple sleeves, but without the stock sleeve. The increase was amazing. I gained so much low end, and a little on the top end too. If you have ever lookat the port itself, the runner ends in a flat dead end a few MM past the end of the port. Thats horrible for airflow, and you can tell by driving a car like that.



I spent so much time trying to get that engine to run as good as a car with a working 6 port system. And no matter what I did, I still could not come close to the drivability of having working 6 ports. On the motor I just ported and built for my car, I made the 6 ports operational. I also made some nylon pieces like the pineapple sleeves, and did a little modifying of the 6 port sleeve so it isnt as much of a restriction. And you know what? My heavily ported motor with workign 6 ports has much more bottom end than my old stock port motor with the sleeves removed.



I think youre just wasting hp for the sake of being lazy if you wire your ports open or otherwise. A stock or even street ported motor will only lose low end, for no gain in the top end if the sleeves are wired open.



If you think its a restriction, go look at your AFM. The intake ports them selves are the best flowing part of the whole motor. With the stock ecu and manifold, there is no way to make the engien flow enough that the 6 port sleeves becoem enough of a restriction to actually have a negative effect on the powerband.

ChainSawOnSteroids

i like learning things, thanks for the info, but ill probably just remove mine, as im a lazy ****, and i dont care about low end

ChainSawOnSteroids

i used tie wraps to make mine stay open, works just fine

rxseven

Mazdaspeed7,

It's interesting to see such different observations on the same subject. A guy on the 1st gen mailing list sent me a dyno sheet of his stock port GSL-SE with the 5/6 sleeves removed. His max power was 153 rwhp and 135ft-lb. of torque. If I can get him to mail me a link, i'll post it here. It did show max torque at 5k rpm rather than at 3k rpm for a stock GSL-SE but the chart showed the torque at 3k rpm to be around 105 ft-lb. which is not too shabby considering the max torque is 135. Having around 175 Hp at the flywheel is pretty nice with just a header and s-afc so it can't be all that bad!

As for dave lemons comments, he used to post on the "other" forum on rare occasions with the mazdatrix username. Unless it was an impersonator, that's where I found the comment.

mazdaspeed7

I base my statements on much more than peak power/torque. If its a race only app, go ahead and pull the sleeves, theres no real need for them. BUT the people asking here dont have race cars. Street cars spend SO much of their time in the lower rpm ranges. Drivability is more of an issue than a few extra hp at the peak, while losing LOTS of torque down low where the car gets driven nearly all of the time.



People say its not bad, they just downshift if they need to go. But why give up drivability like just for a minimal(at best) gain at the power peak? its not like you would even notice the gains, but I can gaurantee youll notice the losses.

j9fd3s

i should dyno mine both ways (i wanna dyno it anyways), one stock working 6 ports, one wired open, one wired closed, i'm waaaay to lazy to take the manifolds off, if the ports work, so you dont get that one, hmm.

time to call gd.



mike

1Revvin7

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