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I installed an E-303 cam in my 93 GT that has a GT-40 intake and Fox Lake TFS Twisted Wedge Stage 1 heads. I had the car dyno'ed and it had 267 HP at the rear wheels. While the cam sounds awesome at idle and the power feels good, the car bucks going down the road in fourth or fifth gear below 2500 rpm. I don't like the cam and want to replace it with one that is smoother. Can anyone recommend an emissions legal cam that will give better performance than the stock cam but not have the roughness of the E-303? I am also going to replace the GT-40 intake with a TFS street heat intake. The car is driven 99% of the time on the street commuting to work but I want it to have enough power to pull some good times at the track.
 

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I have a 65mm throttle body with the stock injectors and stock Mass air meter.
 

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I was initially thinking that your mass air was bad or you were getting turbulance from fan wash going into your mass air causing your car to buck, but I could be way off also.
 

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I'd say that if you go to a smaller cam your combo will be even more unbalanced. You will have a well selected combo of heads and intake which are designed to perform best above 3000RPMs and a wimpy cam that won't support the RPMs. Your car will still not realize it's full potential. Plus you have a really tall gear for those heads and the TFS intake.

Unfortunately you can't have really good low end torque for smooth street driving and huge HP numbers on small displacement engine like the 5.0. Your combo just won't match. I'd go to a cam that is well matched to your heads and intake and get rear gears that will keep your RPMs where they need to be for the best street driving. I'd think 4.10 would be about right.

I'd call Ed Curtis and have him custom design a cam for you. He can give you the 70% solution to your compromise between low end torque and also make the best of your setup.

When I called about replacing my "B" cam he was brutally honest in telling me what I'd have to change on my combo the get it to work together properly as a daily driver that only goes to the track 4 or 5 times a year. Essentially he told me not to even buy a cam until I took care of several other issues first because I was wasting my money.
 

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I can tell you my personal experience with aftermarket cams in my car. I've had the stock cam with 1.6 rockers, a B302 with 1.6 and 1.7 rockers, a B303 with 1.7 rockers, an XE270HR-12 on a 108IC with 1.7 rockers, the same cam on a 114IC with both 1.7 and later 1.6 ratio rockers, and a TFS2 cam on a 111 with 1.6 rockers. I can tell you it is hard to look in a catalog and tell what is going to give you mild manners. As a matter of fact, every one of these gave thier own headaches. Some liked to buck, some some just didn't like to go. What helped me more than anything else was getting a Tweecer and learning to tune out the problems. Don't get me wrong, the E303 sucks for your setup, but the drivability problems may or may not be fixed by a simple swap.
 

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Discussion Starter #8
How hard is it to learn to use the Tweecer?
 

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I achieved similar rwhp numbers in a much milder 95 (although similar to yours in many respects), see sig for details. I would bet that using the Baby Crower (212/531 both sides) would get you where you want to go. My 95 was the wifes car, it sounded and drove like stock but put down numbers equaling cars with more mods and $ spent(I used the stock intake ported!).
I have put together other cars with "big" heads and small cams, and they can work if the lobe is aggressive and the valve timing is right.
For an off the shelf cam the Baby Crower would be great. Of course, having one of the popular cam consultants here on the Corral spec one out for you could work even better. Also check out the Comp hyd roller cams in the milder versions, they also work well.
Lastly, get it tuned by an expert. Donnie Walsh did my 95, and it was exceptional.
Let me know if I can help further and good luck.
 

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Check out: http://www.wighat.com/fcr3/FMScam.xls

With the E cam, the minimum static compression required for best power is 10.25:1 (I'm not sure if that was for iron or aluminum heads?).

Anyway, you can see that your combo's probably low on compression. Some more compression would probably help more than anything.

As for the idle & low end, the overlap/separation will mainly dictate it's behavior.

Overlap = (int_dur + exh_dur) / 2 - (2*LSA)

The E cam (crane 2040) is right at zero:
(220+220) /2 - (2*110) = 0

Some more lobe separation should help.

The stock cam is around 211 with 115 lsa (-19 degrees!).

Check out the TFS stage 1 cam, which is made for your combo!
I think it's (218+221) / 2 - (2*112) = -4.5

I'm not sure about PV clearance, but you might check out a mild comp cam extreme grind or the crane 2030 (216/220,112lsa, -6 degrees overlap).

The Tweecer is fun :D

You've probably openned up the throttle butterfly to raise the idle. Have you made sure the TPS is less than one? If not, the computer won't know it's supposed to be idling.

Also, with the TB openned up, the computer can't use the Idle-Air-Bipass to properly control the idle. Some people use a block-off plate to eliminate the surging.

The EEC tries to idle around 670 RPM... too low for a big cam.

With the tweecer, you can back off the throttle (so there's actually a choke in the cold!), and let the EEC control the idle with the IAB... at whatever idle you'd like! Mine idles nice at 840 RPM... even in the cold.
 

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i know that the e-cam isn't the latest and greatest cam out there BUT you should have made more power than 267rwhp.

what makes you think it's the cam?
who installed the cam (straight up or advanced)?
what condition is the shortblock in?
what was the a/f ratio?
can you post the graph?
 

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bjboudre said:
I have a 65mm throttle body with the stock injectors and stock Mass air meter.
get a REAL meter before assuming its the cam!
:rolleyes:
 

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Change your meter and injectors before you do anything. At minimum get a TwEECer to add more fuel, those injectors probably just aren't supplying enough to feed it. E is not the best cam out there but you should be making more than 267.

I made 268rwhp w/stock heads slightly ported & large vls, GT40, 65mmTB, 75mm Meter, B303 and 24lb inj then adding box stock TW heads and noticed a huge improvement right across the board!
 
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