Cam for a 2800lbs. car.
Cam for a 2800lbs. car. So if I can ever get my hands on a pullout, I'm dropping an LS1/T56 into my 3rd gen RX-7. I was wondering about cam selections as far as what to look at. From what I've been reading, it seems like 228/232 or 230/232 would be a good choice, but I was wondering if I could get away with something a little bigger. This car's my DD, so it has to be streetable, but I didn't know how much the weight would have an effect on selections. Any info/advice would be greatly appreciated as I'm coming from the rotary world, so I'm having to relearn about piston engines.
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Joined: Jan 2007
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From: Pusan, ROK
Depends on your gearing, how much you want to pay for gas, whether you are going to do a lot more engine mods down the road and a few other things.
If you want the a wild sounding car I think that RX7 would probably benefit more from one of those violent ramp and high lift/duration cams than a stockish F-body would. And you can get some good performance w/o even changing the heads if you were on a strict budget.
If you want something tamer then a mild cam/heads would give you just as much power (maybe lower peak numbers, depending on cam, but probably better E/Ts). PP LS6 heads that flow amazing numbers are going for around $900 now. And the milder cam would be easier to drive and get you better city mpg.
It mostly depends on your preference.
If you want the a wild sounding car I think that RX7 would probably benefit more from one of those violent ramp and high lift/duration cams than a stockish F-body would. And you can get some good performance w/o even changing the heads if you were on a strict budget.
If you want something tamer then a mild cam/heads would give you just as much power (maybe lower peak numbers, depending on cam, but probably better E/Ts). PP LS6 heads that flow amazing numbers are going for around $900 now. And the milder cam would be easier to drive and get you better city mpg.
It mostly depends on your preference.
with a car that light you could go with a fairly large cam since you shouldn't need as much torque to get that thing moving. something like a torquer2 (232 234) or similar would be a decent choice.the tune is what makes or breaks driveability.
I've got the same question only my Rx7 is going to be stripped and be around 2400-2500lbs. This is a weekend car at best and barely streetable. I wanted to go pretty damn wild.. probably either a TRex or bigger. Just wanted to know what you guys thought of that.
Yeah, while reading up on the board, I had to keep reminding myself that my car's a lot lighter than an f-body, so I could probably get away with a cam that's a little larger than usual. I'm probably going to stick with the stock heads for the time being, but will have LTs and pulley at least. Later on I'll be looking for better heads, 90/90, 100 shot, etc. etc. As far as gas mileage goes, anything's going to be better than what I got on the rotary, 14-15mph city and 19 at best on hwy, so no worries there. I think my biggest problem is going to be traction, so losing some torque down low really isn't a concern.
I'm running a comp XE-R 232/240 112+4 in my rx7. I just put it in yesterday, but I broke my stock pulley taking it off, so I ordered an aftermarket one and now I have to wait for it =(
Another fact that might not be too well know in these parts, is that almost all rx7s have a 4.11 final drive, and the only other(simple) option is a 3.9. With a lighter car and this gearing, you can pretty much get away with whatever you want as long as its tuned properly. I will be going to a 3.55 final drive via 03/04 cobra rear, and don't intend to have any problems with the cam I'm running.
In a street car, I would try to keep the power down in the useable range, something in the upper 220s to 230s for duration, keeping decent compression and valve events should do well. If you want all that you can get out of it, then one of the big popular cams(t-rex, ms4, vindicator) would make good choices - but they do come with disadvantages, like being hard to tune, having an *** hair worth of ptv, won't really take off until 3-4K+rpm...don't forget the toll lots of high rpms can take on your engine.
I love the way the stock cam just rips from down low, but hate how it falls down a bit up top. I hope the cam I chose will be a good compromise, but I guess theres only one way to find out for sure...
Another fact that might not be too well know in these parts, is that almost all rx7s have a 4.11 final drive, and the only other(simple) option is a 3.9. With a lighter car and this gearing, you can pretty much get away with whatever you want as long as its tuned properly. I will be going to a 3.55 final drive via 03/04 cobra rear, and don't intend to have any problems with the cam I'm running.
In a street car, I would try to keep the power down in the useable range, something in the upper 220s to 230s for duration, keeping decent compression and valve events should do well. If you want all that you can get out of it, then one of the big popular cams(t-rex, ms4, vindicator) would make good choices - but they do come with disadvantages, like being hard to tune, having an *** hair worth of ptv, won't really take off until 3-4K+rpm...don't forget the toll lots of high rpms can take on your engine.
I love the way the stock cam just rips from down low, but hate how it falls down a bit up top. I hope the cam I chose will be a good compromise, but I guess theres only one way to find out for sure...
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Joined: Jan 2007
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From: Pusan, ROK
In my personal opinion of what I would do w/ stock heads:
Get some really agressive lobes with around a 240 intake/exhaust and a slightly over .600 lift and a light weight drivetrain (aluminum flywheel, pressure plate, driveshaft, etc. for fast revs and response) with free flowing intake/exhaust and a fuel system to keep up with it. Keep the final gear you have and just spend some money getting that power stuck to the ground (bigger tires, stiffer suspension, lower angle of body weight inertia on that rear end). You will lose a bit of low end torque but with your car's weight (especially if you do some weight reduction) you will not notice much on the lower end torque. Get an amazing tune and you will be smoking most at the track. Plus an RX7 with a large cam and free flowing exhaust would sound amazing, especially from what most would expect. I bet you would be pulling high 10s with slicks and a setup like that and it really isn't THAT expensive.
I don't think this would work as well with a heavier car but would be awesome for the cost on an RX7. Also I'm no expert/mechanic, there are probably others that would have much better ideas than me. Just my thoughts.
Get some really agressive lobes with around a 240 intake/exhaust and a slightly over .600 lift and a light weight drivetrain (aluminum flywheel, pressure plate, driveshaft, etc. for fast revs and response) with free flowing intake/exhaust and a fuel system to keep up with it. Keep the final gear you have and just spend some money getting that power stuck to the ground (bigger tires, stiffer suspension, lower angle of body weight inertia on that rear end). You will lose a bit of low end torque but with your car's weight (especially if you do some weight reduction) you will not notice much on the lower end torque. Get an amazing tune and you will be smoking most at the track. Plus an RX7 with a large cam and free flowing exhaust would sound amazing, especially from what most would expect. I bet you would be pulling high 10s with slicks and a setup like that and it really isn't THAT expensive.
I don't think this would work as well with a heavier car but would be awesome for the cost on an RX7. Also I'm no expert/mechanic, there are probably others that would have much better ideas than me. Just my thoughts.
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i'm not a real fan of the really agressive lobes,especially for a dd car. in my opinion a great cam would be something like a 234-236 on intake, 240 on exhaust with xer lobes on a 112 +4 or so.
^ almost the exact cam rosey has.
with a final drive of 3.90 or 4.10 you can use a slightly bigger stick.i didn't know that was about the only option in those cars,learn something new every day.
pm someone like predator z or some of the other guys that are really in the know on these lsx engines and see what they have to say.
^ almost the exact cam rosey has.
with a final drive of 3.90 or 4.10 you can use a slightly bigger stick.i didn't know that was about the only option in those cars,learn something new every day.
pm someone like predator z or some of the other guys that are really in the know on these lsx engines and see what they have to say.
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TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Yeah, plenty poeple, this is basicaly a G5X3 but with a +2 advance instead of +4. Since you're M6 and a light car the +2 will carry a bit further in the rpms.
What yoear is the block you are putting in?
What yoear is the block you are putting in?
It's an '03. I finally found a pullout lastnight and will be driving to get it soon. I don't know if there are any mods done to it already, but I'll just assume it's stock for the time being. I had found a site that listed the differences between the different years, but I can't find it now.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
That is good. 03 is a good year, rod bolts and block design are finaly refined by then, intake is LS6.
I'll give you my honest opinion. A good cam that will act big and provide good flat trq across with nice high rpm output, minimum supporting mods and very nice performance IMO would be a reverse split.
230/228 .592/.588 110-1 LSA (Yes you're reading correctly retarded 1* for VE tailoring), custom order Comp Cam XE-R grind
Valve Events:
IVO>4
IVC>46
EVO>43
EVC>5
ECL> 109
9* Overlap
Description of behavior:
>It is intake biased from TDC so it will have the means to carry very well past peak
>It has a 46* IVC and due to LS6 intake it will peak in the 6300 rpm neighborhood.
>It has 43* EVO so midrange trq for acceleration will be really strong and very flat trq curve
> 9* Overlap is a nice chopchop with plenty power potential (equivalent to a 232/234 112)
The power band should be from 2200>6700
I'll give you my honest opinion. A good cam that will act big and provide good flat trq across with nice high rpm output, minimum supporting mods and very nice performance IMO would be a reverse split.
230/228 .592/.588 110-1 LSA (Yes you're reading correctly retarded 1* for VE tailoring), custom order Comp Cam XE-R grind
Valve Events:
IVO>4
IVC>46
EVO>43
EVC>5
ECL> 109
9* Overlap
Description of behavior:
>It is intake biased from TDC so it will have the means to carry very well past peak
>It has a 46* IVC and due to LS6 intake it will peak in the 6300 rpm neighborhood.
>It has 43* EVO so midrange trq for acceleration will be really strong and very flat trq curve
> 9* Overlap is a nice chopchop with plenty power potential (equivalent to a 232/234 112)
The power band should be from 2200>6700
Last edited by PREDATOR-Z; Jul 13, 2007 at 01:07 PM.
Originally Posted by slow trap
i'm not a real fan of the really agressive lobes,especially for a dd car. in my opinion a great cam would be something like a 234-236 on intake, 240 on exhaust with xer lobes on a 112 +4 or so.
The tune will ultimately determine how streetable it is...I wouldn't worry much about streetability, as even a trex could drive like a baby if you put the time in working the bugs out, or paid someone else to put the time in.
The reverse split that predator mentioned would work nicely, although I wouldn't have chosen it because it wouldn't work quite as well with 150+ hits of spray. Glad to see his first recommendation isn't too far from what I have
The reverse split that predator mentioned would work nicely, although I wouldn't have chosen it because it wouldn't work quite as well with 150+ hits of spray. Glad to see his first recommendation isn't too far from what I have