Need cam advice from you experts :-)

[mto502]

Hi guys

I have a 95 GTS with 31,000 k's on stock block and I just modded her up last summer. I have a Trick Flow Track heat intake, Canfield heads(2.02/1.60 ) match ported to intake (have flow numbers), stage 1 TFS cam , 1.6 rockers,MSD 6AL, 24# injectors, 255 lph pump, BBK cold air intake, BBK 70 mm TB, 75 mm Pro-M mass, Kirban pullies, catted X-pipe, Mac shorties, Flowmaster cat back 2 chamber mufflers, 355's.

I dyno'd 280 rwhp and 317 rwtrq. I didn't have the pullies at that time so lets say maybe I'm at 285 rwhp now. The TFS cam I have is very mild and I'm not even close to taking advantage of all that beautiful port work. Flow numbers will be at bottom of this post.The other thing I've noticed since the mods is oil consumption has increased. I thing the intake is sucking some in through the PCV valve since aftermarket intakes do create more vacuum. Anyway I'm leaning towards either a custom grind or just going for the Ford Camzilla Z303 cam.

My best ET is 13.6 @ 104.6 mph with an almost 2.2 60 ft time on street tires. I think my cam isn't performing and my trap speed should be at least 107 mph. I also want to break the 300 rwhp barrier. I should add I'm running with stock computer and stock fuel pressure regulator and my A/F is 13.5:1.

Any input is appreciated. Rick

My flow numbers are as follows
Lift: Exhaust:
0.100 73 64
0.200 137 102
0.300 193 148
0.400 247 177
0.500 279 190
0.550 281 194

 

[NIIIIICE]

Rick, has the cam given your car any ideling problems?

i went with the steeda19 cam caus ei was concerned with the ideling surging issues found with our processors

 

[mto502]

Hi Steve. No the car runs fine. I'm just stewing over the money spent on extra porting when I'm not taking advantage of it. My numbers should be higher and my times should also be better at the track. Maybe not my ET so much (traction issue) but my trap speed more importantly.

 

[Joes95GT]

Those are some SERIOUS flow numbers for a SBF head, especially one going on a stock shortblocked 302. You would need a cam somewhere in the .550 range with 22x/22x duration to take advantage of that head. Unfortunately, with the 2.02 valve, I don't think you could run as much camshaft as you could with a 1.90 valved car. Did you check PTV clearance with the TFS stage 1 cam? I'd be willing to bet you were under .050 clearance on the intake side.

Are the flow numbers on paper? If so, I would sell those heads, showing the flow numbers attained from those heads and buy a head better suited for a 302, such as an AFR 165 or Edelbrock Performer. You can run in upwards of 230 degrees of duration on both sides of the cam - something you may not be able to do with your current head.

What seems weird to me is what you said - the car should be trapping around 107 or so. Your time of 13.6 @ 104 is about right. It seems that the car is running "how it should". I would venture a guess that you are lacking air flow (velocity), which is killing your times. What size are the intake runners on those heads? Also, the cam that you have in there is too small for the head/manifold combination you have, however, like I said before, I don't think you could get away with much more cam.

If it were my car, I would sell those heads.

Joe

 

[mto502]

Thanks Joe. I just bought these damn heads !!!! I'm am looking at a cam in the 550 range. I should add that the pistons were flycut and are good for up to .600 lift. I also have double springs. The heads are 54 CC's for added compression since I don't plan on going forced induction. Hopefully these small details I forgot to mention will change your opinion on these heads. Yes my flow numbers are on paper. They were only mildly ported as the factory numbers for these heads were already decent.

Rick

 

[green94droptop]

If you just got your short time down into the 1.7 range, you'd probably trap 107 pretty easy. HP number don't mean anything anymore. 280rwhp is pretty good in my opinion.

 

[mto502]

This is a sample of my dyno. This was the only pic I could find. The torque is down in this pic due to the discovery of a vacuum leak later on. The horsepower curve levels off and drops too fast. Cam related I'm sure.

 

[green94droptop]

Why would vacuum matter on a dyno? There's no vacuum under WOT.

 

[mto502]

Why would vacuum matter on a dyno? There's no vacuum under WOT.

Any cam suggestions ?

The finding of the vacuum leak made about 16 rw ft lbs of torque difference. Either that or the torque just magically appeared on the dyno after reconnecting a hose to the bottom of the intake.

 

[Joes95GT]

Thanks Joe. I just bought these damn heads !!!! I'm am looking at a cam in the 550 range. I should add that the pistons were flycut and are good for up to .600 lift. I also have double springs. The heads are 54 CC's for added compression since I don't plan on going forced induction. Hopefully these small details I forgot to mention will change your opinion on these heads. Yes my flow numbers are on paper. They were only mildly ported as the factory numbers for these heads were already decent.

Rick

The heads are good for .600 lift, but for how long is the question. You can run a cam with .400 lift and run into problems if they valve timing is wacky. You want to keep the LSA tight on an N/A cam, however, our computers don't like that. You would either need some form of tuning device or a custom burned chip after the cam install.

I forgot to ask the most important question - is this a street/strip car, or a street car, or what? Look into Comp cams, something like a XE274HR would be good for a more drag oriented car. Something like a XE266HR would be better for a daily driven or street driven car. Driveability would be affected somewhat (by either cam), but I think that should be expected. Whatever you do, make sure to check PTV clearance.

Joe

 

[mto502]

PTV ? Did you read my reply to your 1st post? Advancing a cam reduces rpm and my rev limiter is set at 6000 rpm anyway.

 

[mto502]

This would be mostly a street car. My computer accepted the cam I have now. I want drivability. From what I understand the Z303 is still a very streetable cam. I believe the 95 computer seems to learn once you've driven the car for a while. It gets smoother and works bugs out in my experience with what I've done to the car so far.

Remember I have no desire to go as radical as .600 lift. I just want a nice all around cam that's going to net me more horsepower and torque without drivability issues.

If I can't find something off the shelf to match my flow numbers and hardware then I m ay have to go custom grind I suppose.

 

[Joes95GT]

Generally, durations in excess of 220* and LSA's tighter than 114* are what give our computers problems. Your cam is a little on the small side, which is why you didn't have too many problems, if any at all. The Z cam would give you more problems than you could imagine, it's designed for a more drag oriented car anyhow. Because you are looking for so much out of the cam, and there are so many variables in your motor, I would definitely get some type of custom cam. I could guess at a cam that would keep your street manners and give you more power. I would probably be pretty close too, but there is still that key word - guess.

Joe

 

[Killercanary]

What rpm did you shift at when you ran it at the track? The reason I ask is that if it was my car I'd shift that thing at no less than 6000rpms, but you mentioned you have the limiter at 6000. I think you might have more there now as it sits if you rev'd it a little more. You have heads and an intake that should make power well into the 6000rpm range, so cam it accordingly.

 

[stangboy]

Joes95GT, I have a quick question for you. Would that Comp. XE274HR cam cause any more driveablity and idling issue than a cam like an F303? Since I read this post I've been comparing the F303, which I have already, TFS stage 2, and the Comp XE274HR. I like the TFS stage 2 but it has more lift than I want to deal with right now. The Comp cam seems nice but the 110* LSA is making me worry about idle and driveabilty issues. I know my computer will probably accept the F303 better simply because of the 114* LSA. The Comp seems to be the better of the 3 for me, but the 110* LSA is kinda turning me off about it.

mto502, you could probably benefit more from the TFS stage 2 cam.

 

[mto502]

Generally, durations in excess of 220* and LSA's tighter than 114* are what give our computers problems. Your cam is a little on the small side, which is why you didn't have too many problems, if any at all. The Z cam would give you more problems than you could imagine, it's designed for a more drag oriented car anyhow. Because you are looking for so much out of the cam, and there are so many variables in your motor, I would definitely get some type of custom cam. I could guess at a cam that would keep your street manners and give you more power. I would probably be pretty close too, but there is still that key word - guess.

Joe

I'd appreciate your advice in what you believe my cam specs should be Joe. I'll take whatever numbers you suggest with me to my engine builders and he also has a program he uses when determining the best cam. I don't want to lose low end either so it looks like I'll be going with a custom grind, and I also want it to work, at least this season, with my stock computer.

 

[mto502]

What rpm did you shift at when you ran it at the track? The reason I ask is that if it was my car I'd shift that thing at no less than 6000rpms, but you mentioned you have the limiter at 6000. I think you might have more there now as it sits if you rev'd it a little more. You have heads and an intake that should make power well into the 6000rpm range, so cam it accordingly.

If you look at my dyno graph posted above, you'll notice that at around 5400 the horspower drops. I generally shifted at 5500. That's why I'm looking for a cam.

 

[mto502]

mto502, you could probably benefit more from the TFS stage 2 cam.

I was actually reading up the specs on that cam today. It did look interesting however I've had some people in the profession tell me the TFS cam is a cheap cam. Who knows.

 

[Joes95GT]

Joes95GT, I have a quick question for you. Would that Comp. XE274HR cam cause any more driveablity and idling issue than a cam like an F303? Since I read this post I've been comparing the F303, which I have already, TFS stage 2, and the Comp XE274HR. I like the TFS stage 2 but it has more lift than I want to deal with right now. The Comp cam seems nice but the 110* LSA is making me worry about idle and driveabilty issues. I know my computer will probably accept the F303 better simply because of the 114* LSA. The Comp seems to be the better of the 3 for me, but the 110* LSA is kinda turning me off about it.

mto502, you could probably benefit more from the TFS stage 2 cam.

Lets bench race . All cam specs are courtesy of Summit.

F303 Specs:
.512/.512 Lift
226/226 Duration @ 0.050
109/119 LSA

XE274HR Specs:
.555/.565 Lift
224/232 Duration @ 0.050
112 LSA

TFS Stage 2 Specs:
.542/.563 Lift
224/232 Duration @ 0.050
112 LSA

Each one of these cams is going to present idle issues, so that shouldn't even be a topic of comparison. A typical, "good" SBF cam is something that favors the intake side in duration, and most of the time lift. I would immediately rule out the F cam, now we have the other two. As you can tell, these other cams are very much alike, what I don't like about them is that they seem to have about one-hundreth too much lift on both sides. I would pick the TFS Stage 2 just because the lift figures are slightly smaller. Keep in mind that most springs on aftermarket heads experience coil bind somewhere around .550" lift. Check with the seller for max. lift figures and valve spring pressures at the seat and at max lift. They should be somewhere around 150 lbs. at the seat and about 350 at max lift. Please remember that these cams are a drag oriented cam. These two cams will probably have terrible street manners, and will only be able to be driven on the street if the revs are kept over 2000. You are going to want a smaller cam (duration-wise) if you want to keep the car streetable. Please remember that I am no expert, this is just an educated opinion (not an educated guess ).

Joe

 

[mto502]

Thanks Joe

We'll see what Ed says when I talk to him eventually. I need all thias snow to go away before I take the car out.I need to do a compression test 1st. Ed will need that info as well I'd assume.

I would hope that with a custom cam I wouldn't have any drivability issues if it can be ground to suit my setup.