Pettit Update - What we are talking about
04-10-2007, 08:30 AM
#27
Originally Posted by sldrmr21
is there any issues with supercharging the engine? i heard that there was a problem with the engine being a six port as opposed to a 4 port.
I would say if Pettit is on it, making almost 340whp, there probably isnt much of an issue. And if there is, they will probably tell you about it and how to fix it. So, please, what exactly did you hear? and from whom? did your mopar buddies tell you the motor needs to be rebuilt ever 50,000 miles or so?
04-10-2007, 09:32 AM
#28
Fire-Spewing Maniac
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We have seen 340 whp with a turbo setup we have done on track cars, not with our supercharger, although with the right size is attainable via supercharging.
We have used the car on the track with the supercharger and the temps have been good.
We do reccomend upgrading the radiator though, as it will definately help with cooling.
Mazports fan mod is also a good idea.
We have used the car on the track with the supercharger and the temps have been good.
We do reccomend upgrading the radiator though, as it will definately help with cooling.
Mazports fan mod is also a good idea.
04-12-2007, 10:28 AM
#29
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Originally Posted by mac11
I would say if Pettit is on it, making almost 340whp, there probably isnt much of an issue. And if there is, they will probably tell you about it and how to fix it. So, please, what exactly did you hear? and from whom? did your mopar buddies tell you the motor needs to be rebuilt ever 50,000 miles or so?
04-12-2007, 03:25 PM
#31
Originally Posted by sldrmr21
HA! mopar buddies? where did that come from? no, i just thought that because the rx7 engines are similar (im refering to the 2nd gen. engines here) and i know that the NA rx7 are having problems when there being turbo'd or SC'd (something about the port wall because there a 6 port and not a 4 port) but then again i really havent thought about pettit fixing the problems, really i was just rambling or thinking out loud. i was really just curious, and wanted to know if there were problems.
From what I have read the similarities stop at rotary displacement and Mazda.
05-22-2007, 01:53 PM
#35
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05-22-2007, 02:34 PM
#37
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When might this be available guys?
05-22-2007, 08:51 PM
#38
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Im shooting for 280 but im going to have to mod the tranny first. If I see more HP great. I have a good friend in MD that builds outrageously strong automatics. Im planning on heading up there soon and letting him take stab at it. I wouldnt go past 250 HP with the stock auto, thats my oppinion. Like I say if it can be broken ill do it. Im going to let him do mine up and when its done ill post how to get in touch with him for other auto owners that want there tranny reinforced. I havent seen one apart but im pretty sure the bands will take more of a beating causing slippage and im not sure how big the pins in the planaterys are. He will also now about the valve body. I dont have the time or id do it myself and im sure it will take him less then 4 days. Hes never done this perticuler tranny but after mines done his turnaround will be 2 days. He builds them for a living and has stock rebuilds done in less then a day including removal and instal by himself.
05-31-2007, 06:30 AM
#39
Im shooting for 280 but im going to have to mod the tranny first. If I see more HP great. I have a good friend in MD that builds outrageously strong automatics. Im planning on heading up there soon and letting him take stab at it. I wouldnt go past 250 HP with the stock auto, thats my oppinion. Like I say if it can be broken ill do it. Im going to let him do mine up and when its done ill post how to get in touch with him for other auto owners that want there tranny reinforced. I havent seen one apart but im pretty sure the bands will take more of a beating causing slippage and im not sure how big the pins in the planaterys are. He will also now about the valve body. I dont have the time or id do it myself and im sure it will take him less then 4 days. Hes never done this perticuler tranny but after mines done his turnaround will be 2 days. He builds them for a living and has stock rebuilds done in less then a day including removal and instal by himself.
05-31-2007, 07:41 AM
#40
I understand the possible need to rebuild the Auto transmission for above 250whp, but why are the Auto RX-8 guys not using 3rd party Auto Transmission Fluid Coolers and better Auto transmission fluid already?
Its a kind of cheap $300 more or less mod.
Its a kind of cheap $300 more or less mod.
06-01-2007, 07:24 AM
#42
I am using a tranny cooler and RP trans fluid. My problem is shifting my AT at higher RPMs. The tranny does not seem to like RPMs above 7800-8000 for shifting. Hell it will not shift at 9000 RPM and at 8000 thru 8500 is not stable during the shift. My s/c will be installed on June 9th by Charles R. Hill and I expect real problems after that unless I go back to shifting at 7800. Ray is going to have a look at the tranny when he's here so I'll leave further comment to after he looks at it. If your are aware of a company that offers upgrades for the AT please send me a PM or post it.
06-01-2007, 09:54 AM
#43
Your best bet is to go to a true trans shop and see what they have to say about it. All the talk around here is that the trans itself is pretty bulletproof but the torque converter just can't take spinning up that high which is why you are having problems.
And like Al said, the TCU doesn't like full load redline shifts, you will just have to ease off the gas.
And like Al said, the TCU doesn't like full load redline shifts, you will just have to ease off the gas.
06-05-2007, 02:26 AM
#44
I am using a tranny cooler and RP trans fluid. My problem is shifting my AT at higher RPMs. The tranny does not seem to like RPMs above 7800-8000 for shifting. Hell it will not shift at 9000 RPM and at 8000 thru 8500 is not stable during the shift. My s/c will be installed on June 9th by Charles R. Hill and I expect real problems after that unless I go back to shifting at 7800. Ray is going to have a look at the tranny when he's here so I'll leave further comment to after he looks at it. If your are aware of a company that offers upgrades for the AT please send me a PM or post it.
Also, I'm not clear on what specifically your shifting problem is. Do you mean that it appears to stick a bit before letting you shift? That there is a delay between you manually shifting and response?
As far as "stickiness" is concerned, I noticed that it appears to shift when you release. I don't know how to describe it. The faster you attempt to shift and let go, the better the results seem. If you attempt to shift slowly, it seems to "stick" a bit before changing the gears. At lower RPMs, "stickiness" is less noticeable, but at higher RPMs you need to use a faster technique.
I agree that you may need to take it to a transmission expert. Hopefully, someone that might have seen RX-7 and/or RX-8 transmissions before. Sorry, but I can't recommend anyone for you at this time.
Also, there may be something to looking the AT ECU more. I think it gets ignored as many pro-tuners are focusing on the MT and don't care to dig into AT issues. Charles Hill had mentioned doing this before on this board in one of the topics related to this issue. Since you have his services, you should bring it up again.
It would be great to look at how the the Automatic Transmission is being controlled to see if there is any tweaks possible. I just don't hear of anybody using the Int-X in this way for the RX-8 Autos. Maybe it can be done and was just not looked into. Hopefully when the Cobb AccessPort comes out, we may be able to dig into the AT ECU more too.
I'm looking forward to yours and Charles report on the RX-8 Auto install.
Last edited by sosonic; 06-11-2007 at 01:47 AM.
06-05-2007, 07:02 AM
#45
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I won't be able to make any mods to Phil's tranny while I am there but I will get a chance to observe the tendencies of the transmission, itself. Most high-perf. trans work involves modifying the internal pressures the various systems operate under, which is controlled by the valve body(i.e. "shift kit" like those offered by TCI and B+M) as the bands and clutches are usually able to handle abuse they would endure on a street car. In the case of the Phil's 4sp. auto, this issue may be either electronic control-related or an accumulator valve that could stand a little tweaking.
Am I correct in understanding that the '07 models have the 6-port and a 6 speed auto in them? If so, I may be very interested in driving one of those models.
Am I correct in understanding that the '07 models have the 6-port and a 6 speed auto in them? If so, I may be very interested in driving one of those models.
06-06-2007, 06:39 AM
#47
Also, I'm not clear on what specifically your shifting problem is. Do you mean that it appears to stick a bit before letting you shift? That there is a delay between you manually shifting and response?
"Quote sosonic"
0-7800 RPM: mostly solid shifts - occasionally seems to slip (just a little) when at 7800
7800-8500: few solid shifts - seems to slip into gear most of the time
8500-8700: does not want to shift until I let off and the rpm reaches 8000 then seems to wants to slip into gear.
8700-9000: will not shift period - when rpm drops lower than 8000 then seems to want to slip into gear.
Slip: an extended time between asking for a shift and the reality of the shift without seeming to be in any gear. This varies with the RPM at the time of shift. Yes there is always the chance of "operator error" but the AT/4 even leads itself to compensate for that.
Now I would be worried that my tranny was failing if not for the solid shifts at and below 7800 RPM. I checked the Royal Purple tranny fluid and while not scientific, it does not smell burned and is at the recommended level. Ray will look at the tranny when he's here installing the s/c.
I think that with the install of the s/c and the interceptior X that this is a week link and needs addressing now.
"Quote sosonic"
0-7800 RPM: mostly solid shifts - occasionally seems to slip (just a little) when at 7800
7800-8500: few solid shifts - seems to slip into gear most of the time
8500-8700: does not want to shift until I let off and the rpm reaches 8000 then seems to wants to slip into gear.
8700-9000: will not shift period - when rpm drops lower than 8000 then seems to want to slip into gear.
Slip: an extended time between asking for a shift and the reality of the shift without seeming to be in any gear. This varies with the RPM at the time of shift. Yes there is always the chance of "operator error" but the AT/4 even leads itself to compensate for that.
Now I would be worried that my tranny was failing if not for the solid shifts at and below 7800 RPM. I checked the Royal Purple tranny fluid and while not scientific, it does not smell burned and is at the recommended level. Ray will look at the tranny when he's here installing the s/c.
I think that with the install of the s/c and the interceptior X that this is a week link and needs addressing now.
Last edited by Phil's 8; 06-06-2007 at 06:41 AM. Reason: spelling
to get this thing before the end of the year haha