Don't know whether to advance E cam or not. I had two people give me different advice on this, they are both extremly knowledgeable about cars. One said to do it, the other said not to. My car will be a 90 to 95% street car and 5 to 10% track. Sometime in the spring i plan on getting the heads and lower intake ported.
To advance cam or not
- Thread starter kevsstang
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At one time I had a very simliar combo as you. I run the E as of now and is a good cam. I left mine alone. I wouldn't advance it or retard it. With the gears you have you will be fine installing it striaght up. I wouldn't mess with it, especially since it will be mosty street driven. She will kick in hard at 3K. You really don't need a higher power band than that on the street. You'll hardly use it..
Michael Yount
Mustang Master
Most people find that installing the E a bit advanced helps that 'kick' come in at a lower rpm. I don't think he's asking about shifting the power band up; but rather shifting it down.
Yes, Michael you are correct. I just didn't know what to do with the two people giving different advice. I guess the more advice i receive would help me decide what to do. Would there be a benefit to advancing the cam. I think the Ecam rpm range is 2500-6000??? By advancing it would it lower the rpm band, but would i lose much on the top end.
Michael Yount
Mustang Master
Kev - it's hard to say; the cam works in combination with the other parts. I do know a lot of people install the E 4 degrees advanced - open .050" at 4 btdc. Some swear by it - and claim it helps restore some bottom end. If it were mine, and I were going that far into the motor - well, last time I did, I pulled the E out of mine, sold it, and put a custom from Buddy Rawls in. That would be my advice.
I would say that is good advice. How big of a difference between an off the shelf cam vs. a custom. I imagine alot has to depend on what type of custom cam you want, how radical the cam is and what combo. I thought about a custom but have no idea what to order. I do know it has to be emissions friendly.
Michael Yount
Mustang Master
Kev - you don't have to "order" a custom like you do a regular cam. The designers will request a bunch of information from you about your set up (head, intake, exhaust - flow data, compression ratio, stroke and rod length, etc.) and also ask you to answer a lot of questions about what you're after, how you use the car, if it has to pass emissions or not, what kind of idle you can live with, where you want your peak power, etc. -- then THEY model your set up and THEY determine the specs of the cam. That's what makes it a custom.
An off the shelf cam can perform just as well as a custom - IF, big if, IF you happen to guess correctly and pick a cam that works the way you hope it will. I'm not willing to leave that to guessing and hoping - hence the custom route. With the model, the guessing/hoping is pretty much gone.
An off the shelf cam can perform just as well as a custom - IF, big if, IF you happen to guess correctly and pick a cam that works the way you hope it will. I'm not willing to leave that to guessing and hoping - hence the custom route. With the model, the guessing/hoping is pretty much gone.
Michael Yount
Mustang Master
"Is there a difference in HP between the two? If so is there an average number or is it based on the combo. "
Kev - your questions imply you still are not quite grasping what cams and custom cams are all about. Go here (Buddy Rawls' site), open all the tabs and read about how cams do what they do. It'll give you a better understanding of what the custom designers do, and how using an off the shelf cam is just guessing. http://www.wighat.com/fcr3/
HP difference - depends. IF you happen to guess well on your off the shelf, there may be no difference at all in peak HP levels. But very few folks guess right. More important than peak HP in a street car is where the car is making power and where it's making torque. I hated the E in mine - the bottom end was WAY too soft, and fuel economy went all to hell around town; idle quality was miserable. I told Buddy I wanted my stock idle back, with plenty of vacuum and I wanted lots of bottom end - and that I was willing (and understood I probably would) to lose some peak power to gain the bottom end torque back. I would've simply put the stock cam back in but I'd sold it already with other stock pieces from the car. Buddy's cam did EXACTLY what I wanted it to. My gas mileage is actually amazing to me - 18-19 around town, 24-26 highway; we gained 80-90 lb-ft of torque between idle and 3000 rpm (HUGE difference in drivability as you might imagine); and we lost about 15 HP peak - a trade off I was HAPPY to make. The car has a very flat and broad torque curve, and I suspect it's just about as quick as it was before - while the peak power is down, the average power is up (it's not as peaky as it was with the E).
One of the reasons I went this way, and also one of the reasons the E was a bad choice for me was because I have a restricted exhaust set up. My heads are intake biased, and due to some limitations on my chassis, I run 2.25" head pipes into a single 3" exhaust sytem. Buddy designed the cam around those exhaust restrictions - my custom has a lot more exhaust duration than intake duration. It's a perfect example of me 'guessing' and picking the E, only to find out (the hard way) that my configuration and desires weren't even close to being achieved with that cam. Buddy's modeling showed me exactly what was happening, and why that cam wasn't working well in my case and for what I wanted.
Kev - your questions imply you still are not quite grasping what cams and custom cams are all about. Go here (Buddy Rawls' site), open all the tabs and read about how cams do what they do. It'll give you a better understanding of what the custom designers do, and how using an off the shelf cam is just guessing. http://www.wighat.com/fcr3/
HP difference - depends. IF you happen to guess well on your off the shelf, there may be no difference at all in peak HP levels. But very few folks guess right. More important than peak HP in a street car is where the car is making power and where it's making torque. I hated the E in mine - the bottom end was WAY too soft, and fuel economy went all to hell around town; idle quality was miserable. I told Buddy I wanted my stock idle back, with plenty of vacuum and I wanted lots of bottom end - and that I was willing (and understood I probably would) to lose some peak power to gain the bottom end torque back. I would've simply put the stock cam back in but I'd sold it already with other stock pieces from the car. Buddy's cam did EXACTLY what I wanted it to. My gas mileage is actually amazing to me - 18-19 around town, 24-26 highway; we gained 80-90 lb-ft of torque between idle and 3000 rpm (HUGE difference in drivability as you might imagine); and we lost about 15 HP peak - a trade off I was HAPPY to make. The car has a very flat and broad torque curve, and I suspect it's just about as quick as it was before - while the peak power is down, the average power is up (it's not as peaky as it was with the E).
One of the reasons I went this way, and also one of the reasons the E was a bad choice for me was because I have a restricted exhaust set up. My heads are intake biased, and due to some limitations on my chassis, I run 2.25" head pipes into a single 3" exhaust sytem. Buddy designed the cam around those exhaust restrictions - my custom has a lot more exhaust duration than intake duration. It's a perfect example of me 'guessing' and picking the E, only to find out (the hard way) that my configuration and desires weren't even close to being achieved with that cam. Buddy's modeling showed me exactly what was happening, and why that cam wasn't working well in my case and for what I wanted.
A custom is going to run @$500 after you pay for the cam and new springs. Other than the benefits Mike stated with the events being right for your combo one big advantage of a custom is they have better lobe profiles which ends up giving better average performance. But (and this is just my humble opinion) the parts you have are very similar to the parts Ford recommends to use with the E cam so I doubt you'll see huge gains in going with a custom. I would first have lower intake ported then drop fuel pressure to 39psi (30lb and 42lbs are abit much for your setup) and finally spend money on having someone tune the car well. I also bet you'd see gains in HP and TQ from advancing the cam 2 deg only if you have a chain that allows this but as Mike stated it's a bit of work.
Michael Yount
Mustang Master
His X springs will be fine with the custom cam - my lobe ramp rates and peak lift were greater than the E - the springs have no problems with them. That makes the pricing comparison cam to cam.
I don't think the combo will be making enough HP to overwhelm the GT40 lower - I don't think porting it would result in significant gains.
I don't think the combo will be making enough HP to overwhelm the GT40 lower - I don't think porting it would result in significant gains.
JFYI- my dad has a 91GT with a holley systemax II kit on it that was ported by FTI and he has a custom FTI cam. When Ed sends you a cam it list two recommended intake center lines to install it dependent on the cars weight. Well, my dad was right around the cut off for the two suggestions, so he went with the lighter one. The car just didn't perform as well as we had hoped so Ed suggested trying to advance it 2* the end result was an IMMEDIATE gain of 2-3mph at the track, yet on the dyno it lost 10rwhp at peak, but the car picked up everywhere else as is obvious by the times. It did gain 15ftlbs of TQ at peak. It made the car a lot more fun to drive on the street too as it brought back a good bit of low end. He has since run 11.8 at 117mph in the car and its still a standard bore 302.
How do you know those springs will be fine with a custom cam he'd get? Have you seen the lobe profiles...come on Mike you know better than to make a generalized comment like this. If he gets a custom that doesn't require a spring change than I'm not too sure it's worth the money to make the swap.
Stock Cobra intake flows about 190ish cfm where the GT40Xs flwo over 200cfm (@220ish), how can you say its not holding back performance?
