Another Vote for the Throttle Response Cam

[surfdog4]

Well i just installed the round throttle reponse cam..and I like it. It definitely seems to make the car feel more "sporty" in regular driving.

I haven't had any issue with it being "jumpy" in stop-and-go traffic like some folks have discussed.

I would recommend folks give it a try..if you mod the existing cam it won't even cost you anything...installation was very easy

[Tervuren]

Originally posted by surfdog4
Well i just installed the round throttle reponse cam..and I like it. It definitely seems to make the car feel more "sporty" in regular driving.

I haven't had any issue with it being "jumpy" in stop-and-go traffic like some folks have discussed.

I would recommend folks give it a try..if you mod the existing cam it won't even cost you anything...installation was very easy

I actualy find it easier in heavy traffic, just a small touch of the throttle when you suddenly need to get moving again, or suddenly need to accelerate to change lanes, etc.

For performance driving though, I prefer a more linear throttle offered by the standard cam. If I'm just trying to be aggressive in traffic on the road, the throttle response of my brother's '86 is great, just feather the throttle to be zooming when needed, cuts a lot of time.

My driving style though, involves a lot of subtle throttle moves throughout sections of a corner, rather then a sudden punch, so I prefer it to be linear so I have more control. All a matter of driving style.

[ERAU944]

in actuality, the throttle cam mod or replacement cam is 'linear' where the original cam has kind of a two-stage curve to it. the initial part moves the throttle less (on a curve)... due to the larger, yet decreasing diameter of the circle that it makes. toward the end of the travel the cam changes, it is a smaller constant-rate circle that provides faster opening of the throttle in a linear fashion.

the replacement cams or modded ones are simply a constant-diameter circle and provide a linear throttle opening

that said, i've used both and i find it easier to drive more smoothly on the street with the stock cam, as smaller corrections are more easily made. on the track however i would probably go for the modified or replacement cam since it would take less time to go to WOT.

[thoen]

i heard that a round cam is makeable? i see the prices going from $26. (performance parts) to $40. on ebay. i guess there is no difference? so how can you mod it for free unless you make one yourself??

[surfdog4]

there are at least two versions of "make it yourself" i dont have the links here but if you do a search you will find them...I ended up buying the one because I wanted to have the stock one intact in case I sold the car some day

[thoen]

Thanks.
I will buy the $26. (weltheimer(sp?)) from performance. i will update your post when i get an opinion out of it!!!

[thoen]

i found the article on how to modify the cam:

http://www.dietersmotorsports.com/tech/2001/944_throttle_cam.htm

[hpaulb]

Is there any gain on doing this to an automatic? I have an extra can and can fool around with this in the winter. Also, how do you take up the extra slack in the cable length. I would assume you'd have to adjust the nut by at least an 1/4 inch. Doesn't look like any change in the picture?

[Tervuren]

Originally posted by ERAU944
in actuality, the throttle cam mod or replacement cam is 'linear' where the original cam has kind of a two-stage curve to it. the initial part moves the throttle less (on a curve)... due to the larger, yet decreasing diameter of the circle that it makes. toward the end of the travel the cam changes, it is a smaller constant-rate circle that provides faster opening of the throttle in a linear fashion.

the replacement cams or modded ones are simply a constant-diameter circle and provide a linear throttle opening

that said, i've used both and i find it easier to drive more smoothly on the street with the stock cam, as smaller corrections are more easily made. on the track however i would probably go for the modified or replacement cam since it would take less time to go to WOT.

However, the valve is not linear, so you want a non linear opening of the valve to attain a more linear amount of actualy flow.

[Dana Norris]

My current 944 which I just bought 3 weeks ago, has the modified cam.
My last 944 an 1984 model was stock, the current car does seem a bit sharper upon step in, but has anyone experianced a higher idel RPM?
My 86 idels at about 1200 RPM.


_________________________________

1986 944NA Black with Burgundy Leather
1984 944NA Garnet sold to a Corvette owner in1993
1969 912 modified with 1974 911 2.4 CFI sold to a guy from Alaska
1976 911S modified with 1983 911SC 3.0

[Techno Duck]

Originally posted by hpaulb
Is there any gain on doing this to an automatic? I have an extra can and can fool around with this in the winter. Also, how do you take up the extra slack in the cable length. I would assume you'd have to adjust the nut by at least an 1/4 inch. Doesn't look like any change in the picture?

Automatics benefit from from the throttle cam also, however because you have the extra kickdown cable, you need to make a slight modification to any cam you purchase. Either that just make it yourself.

[ERAU944]

high idle is probably caused by an out of adjustment throttle cam. you should hear a click when the throttle closes (the car doesn't have to be on to hear it). also, when you install the cam, the pedal stop is also supposed to be adjusted so that you don't stretch the throttle cable by pulling harder than would do any good.

it sounds to me like whenever the cable got adjusted at the motor side, it was adjusted too tight. see if the switch clicks, if not, loosen the cable just until it does consistently.

[surfdog4]

yes you must adjust the cable to accomodate the new cam...at least on 85-2's and beyond the adjustment is right near the cam where the cable clears the sleeve..I read on earlier ones it is on the firewall.

If your idle goes up after the cam swap then you need to give the throttle cable some slack.

You also may have to adjust a large plastic bolt that lives in the floor pan behind the accelerator pedal so that the pedal hits it before the cable is pulled completely taut. It's actually easy to get to.

[IXLOR8]

I got a used cam from the PO of the car. I am not quite sure where you adjust the extra cable on a 84 944?

Please help.

Thanks

[surfdog4]

the instruction sheet i got with the new cam said that on pre 85-2 the throttle cable adjustment was where it came through the firewall..that's all i have

[onZedge]

No comment.

[thoen]

i just put on the response cam. NICE difference but Small difference. I am glad i did it just for the initial response when the foot goes on the gas.

[Harpman2]

I installed one last week, and my N/A now puts out 15 HP more than before the install. I'll post the dyno charts after I scan them in.

[marghella]

that dosent make sense it shouldent give u hp

[Rrrockhound]

I believe that was sarcasm.