AT Horsepower Restriction
08-11-2009 | 09:07 PM
#101
08-12-2009 | 01:22 PM
#103
Original Turbo 'd Auto !!
Joined: Mar 2004
Posts: 2,133
Likes: 4
From: Surprise, Arizona
Wow with all this banter going on, looks like i missed out..
The 4port intake manifold wouldn't be that hard to remake into something that flowed smoother and better.
After looking into it's design it appears to direct more air into the rear rotor in a pressurized situation.
Thanks for the kind words Phil.
The 4port intake manifold wouldn't be that hard to remake into something that flowed smoother and better.
After looking into it's design it appears to direct more air into the rear rotor in a pressurized situation.
Thanks for the kind words Phil.
Last edited by 09Factor; 08-12-2009 at 02:35 PM.
08-12-2009 | 01:27 PM
#104
08-13-2009 | 03:24 AM
#105
Here are some of the pics during the porting I did for Phil's engine. These are unfinished. Only issue is Mazda made the ports as big as they could. They really didn't leave a lot of room for enlargement. The water jacket is close to the port sides so you can't cut a whole lot out.
Mainly what I did was to smooth the flow. There are some casting edges inside the port that were removed. And made the trailing edge a bit higher and a little larger.
Now as discussed I don't see an issue with obtaining 275+ WHP out of the 4 port with porting and a decent FI kit.
I still need to dyno mine since the 75 shot was hooked up and tuned and the dwell reset on the BHR coils. I'm thinking I have a little over 200 WHP at this point in time.
Plus we are still working on a few things with the higher N2O shots. 100 shot here I come.
Mainly what I did was to smooth the flow. There are some casting edges inside the port that were removed. And made the trailing edge a bit higher and a little larger.
Now as discussed I don't see an issue with obtaining 275+ WHP out of the 4 port with porting and a decent FI kit.
I still need to dyno mine since the 75 shot was hooked up and tuned and the dwell reset on the BHR coils. I'm thinking I have a little over 200 WHP at this point in time.
Plus we are still working on a few things with the higher N2O shots. 100 shot here I come.
08-13-2009 | 04:10 AM
#108
My car has 81,000 miles on it. The AP has been on for 40,000+ miles (9000 redline). And the original transmission. I've changed the fluid twice now and both times it is clear and red. NOT burned at all. It's due to be changed again and I'm going to try Enos AT Fluid this time. It's still clear and red and unburned. I've been using what the dealer recommends so far. And I do the power flush when it's gets changed.
What Phil was referring to is that the transmission will "slip" (rpms shoot up) when engaging 2nd to 3rd gears. Sometimes. It does this regardless of the rpm preset redline. 7500 or 9000.
I've owned two AT 8's (4 speed)and they both did it. If your in second gear for an extended period of time (cruising at say 6000 rpm) and floor it and shift into 3rd. It sometimes does not immediately engage. And the rpm's increase with no load on the trans before it does. It does not do this all the time.
Now Mazda looked at both my cars and had no answer or resolution to this issue. They attribute it to high fluid pressure on the shift solenoid. So I let off the gas a little and it works fine.
That is the only issue I have with the AT transmission and it really isn't that big of a deal.
What Phil was referring to is that the transmission will "slip" (rpms shoot up) when engaging 2nd to 3rd gears. Sometimes. It does this regardless of the rpm preset redline. 7500 or 9000.
I've owned two AT 8's (4 speed)and they both did it. If your in second gear for an extended period of time (cruising at say 6000 rpm) and floor it and shift into 3rd. It sometimes does not immediately engage. And the rpm's increase with no load on the trans before it does. It does not do this all the time.
Now Mazda looked at both my cars and had no answer or resolution to this issue. They attribute it to high fluid pressure on the shift solenoid. So I let off the gas a little and it works fine.
That is the only issue I have with the AT transmission and it really isn't that big of a deal.
Last edited by WTBRotary!; 08-13-2009 at 04:26 AM.
08-13-2009 | 08:39 AM
#109
Now do you have a secondary tranny cooler though that is the question... because id totally buy a Cobb AP with MM's tune if I could run it safely... o and lets not mention the torque converter... I thought it couldnt keep up very well and do its job very efficently which is another reason the redline is limited to 7500rpms...
I drive like a great grandpa (cuz I am)
but Erick is crazy
with his driving and if the tranny can stand up to him then I would say it's strong.
08-13-2009 | 08:45 AM
#110
Erick, mine is a Racing Beat twin catback and a Pettit straight pipe (no resinators). I think it's a little quieter than yours due to the s/c. I have a little drone I would like to get rid of and am counting on the BHR single resinated mid pipe to control.
08-13-2009 | 05:25 PM
#111
Alright well sorry I missed the one saying you had one, would both of yall recommend waiting to get the Cobb AP before I get a new radiator or after? or maybe just a secondary tranny cooler? Im just trying to find out if its safe without those 2 to be running the A/T around 8750 rpms with just the Cobb AP...
08-13-2009 | 05:57 PM
#112
Thanks Charles... Ill try to save up some money and go out and get the Cobb AP with MM tune real soon... kinda excited to see a 8750RPM redline on a auto... hmm I wonder how much different my car will feel now...
08-13-2009 | 06:36 PM
#113
08-13-2009 | 08:08 PM
#115
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Joined: Jul 2008
Posts: 324
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quik update on my 6-port a/t.. My engine is back in the car running better than ever. I'm about to order Cobbs AP and a midpipe from corksport... im in the process of looking for a MT drive shaft(carbon fiber).. The MT driveshaft fits perfectly on the AT transmission. That should put a couple more HP to the ground...
in about 2 weeks i will start ordering the turbo parts.
in about 2 weeks i will start ordering the turbo parts.
08-15-2009 | 03:25 AM
#125
whoo hoo i got my BHR midpipe installed today, its quite a difference..not a big one but nonetheless feel-able on the AT especially going to 8500 rpm 
cant wait for the rest on my future mods.
cant wait for the rest on my future mods.