Cam Selection Help

The first question you have to answer is what are you going to do with the car?




Far too many people put a dab of this and a dollop of that, and then wonder why the car doesn't run worth beans. Then they think off the shelf computer chips will fix their mismatched parts problem. It won't

You have to have a plan for what kind of performance you want: Hot street. Street/Strip, Pure strip, Autocross or Road course. Each one requires a different strategy and a different set of components.. Mismatch the components and you’ll have a car that falls flat on its face when you demand performance.

Everyone thinks HP! HP! HP! and thinks that peak HP is what they need. Peak HP is great for a drag strip car when it has the proper gears and tires to get the car up into the high RPM range where it develops that high peak HP near the finish line. On a street car, that strategy will have Honda Accords outrunning you, because you will never get the engine RPMs high enough without running over everything in your path.

Here’ the strategy: Always remember that there are some tradeoffs in any engine combination. Most of us don’t have enough money to “have it all” as if it was possible by some masterful combination of parts and tuning.

The following recommendations are for 5 Speed Manual transmission cars without NO2 or pressurized induction, stock short block.
1.) Hot street: Broad flat torque curve, high velocity airflow in the intake and heads for best throttle response. Gears suitable for reasonable gas mileage and long road trips without excessive engine RPMs. Stand on the gas pedal from a rolling start to squeeze into that gap in traffic in front of you, and it jumps quick and hard to get you there. Max RPM’s are 5200-5500 RPM for best power. Lopey cams may sound cool, but run poorly in a low RPM street environment.
Use stock cam, stock, GT40 or mildly ported stock heads, Cobra or Explorer/GT40 intake, advanced timing, stock 19 lb injectors, stock fuel pump. Use some good 1.6 or 1.7 ratio roller rockers for extra punch. Use a King Cobra clutch, with stock iron or steel billet flywheel. MAF cars can use a 65 MM TB from the Explorer intake manifold and a 70MM MAF from a 94-95 Mustang. Drive train: 3:55 gears with soft tread compound tires. Use some Ford Racing unequal length headers, stock 2 1/4” cat pipe and some mufflers that don’t drone or get too much attention from the law enforcement or neighbors. The stock computer will handle all this with no problems and doesn’t need any help in 90% of the cases. No skinny or grossly undersize tires for the front: remember you still have to stop quickly in traffic. Make sure all the rubber bushings in the front and rear suspensions are in first class shape. Leave the emissions equipment intact and working. Removing or disabling it won’t get you any more HP or performance. Do not convert to carb or remove A/C: either one will reduce the resale value. Carb conversions cannot be titled for street use or get tags in some places. They definitely won’t pass smog inspections.

Street/strip: A little more slope to the torque curve with a gently sloping peak. Use slightly larger port volumes on intake and heads for more peak HP. Uses 3.55 or 3.73 gears to get the RPM’s up into a higher range quicker. Be prepared to sacrifice some low RPM throttle response in exchange for high RPM power. This by necessity will be a Mass Air or Mass Air conversion on 86-88 5.0 Mustangs, since stock speed density will not run well with the changes in engine airflow. Don’t get too crazy on any one engine part since you still have to drive the car on the street, and a mismatch can make street driving miserable.
Use stock or mild aftermarket cam, Ported GT 40, or 165-180 CC port volume aftermarket aluminum heads. Use a Trick Flow, Edelbrock Performer or equal intake manifold. Take a 73 MM aftermarket MAF calibrated for 24 lb injectors, and 24 lb injectors, 155 LPH fuel pump, Kirban adjustable fuel pressure regulator. Be prepared to shell out some $$$ for a custom burned chip using data gathered from a dyno run. Mass market chips will not get the job done. Use some Ford Racing unequal length headers, aftermarket 2 1/2” cat pipe and some mufflers that don’t drone or get too much attention from the law enforcement or neighbors. Drivetrain: expect the stock T5 to fail, so save your money for a super duty 5 speed trans. Tremec 3550, TKO 500 & TKO 600 are the best choices. Different gears in a stock T5 case work for some, but there is only so much power you can pass through a T5 in race mode before it breaks, even with stronger gears. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Carry spare tires and wheels for the drag strip: skinnys for the front and drag radials for the rear. No skinnys for street driving! Over 85% of the breaking power is generated by the front tires, so skinnys won’t do the job in a panic stop situation. Disconnect the front anti-roll bar at the strip; reconnect it before you drive home. Leave the emissions equipment intact and working. Removing or disabling it won’t get you any more HP or performance. Do not convert to carb or remove A/C: either one will reduce the resale value. Carb conversions cannot be titled for street use or get tags in some places. They definitely won’t pass smog inspections.

Strip only: High RPM, High flow heads (185-215 CC port volume), wild cam, high flow intake manifold, 70 MM or larger TB, 80 MM or lager MAF, strip everything out of the car that doesn’t make it go faster. Carbs are OK if that’s what you want, but remember that as the temp/humidity/ barometric pressure/altitude changes, you have to re-jet and readjust the carb. EFI eliminates most of that with its built in compensation or you can tune of the fly with a high end Motes or Tweecer system combined with a wide band air/fuel ratio meter. Use custom headers, dumps and minimal mufflers. How fast you can go on 5 liters is a function of the skill level of the driver/mechanic and the size of your wallet.

TRAILER the car to the race track since it won’t be legal to drive it on the street. Drag slicks in the rear, skinnys up front, use 3.73 or bigger gears (4.xx) in the rear axle. Since you won’t be driving on long trips, the big gears with work with the high RPM power curve to get the best results. Drivetrain: TKO 500 & TKO 600 are the best choices. Different gears in a stock T5 case work for some, but there is only so much power you can pass through a T5 in race mode before it breaks, even with stronger gears. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Remove the front sway bar, put an airbag in the rear spring of the side that spins the tire the most. Plan on a roll cage if you are truly serious about going fast: most strips will require it once you get to a certain ET range.

Autocross is a combination of Hot street engine and street strip chassis prep. The engine must accelerate quickly from low RPM and needs a broad, flat torque curve. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Most of the time you’ll never hit third gear, so some 3.73 or bigger gears (4.xx) may help a lot. You’ll have to spend some more money on brakes since it kills brakes quickly. Rear disks, larger rotors up front, stainless steel brake lines, different brake pads. A 87-88 T Bird Turbo Coupe or SN 95 rear axle will be your best bet. Autocross will severely strain 1st & 2nd gears, so your T5 may take a premature dump. Save your money for a super duty 5 speed trans. Tremec 3550, TKO 500 & TKO 600 are the best choices.

All out road race is the most difficult of all: an engine that will run at high rpm hour after hour and never fail, yet pull hard out of the hairpin turns that will require a lot of torque at lower RPMs. In my opinion, guys that can successfully build a winning road race engine are the cream of the crop. Top this off with a chassis built for strip only duty, but with changes to the settings of springs, tires, roll bars brakes and shocks. It’s a whole other world of racing.
You’ll have to spend lots more money on brakes since it kills brakes quickly. Rear disks, larger rotors up front, stainless steel brake lines, different brake pads. Air ducting to cool the brake rotors will be a must. The brake rotors of cars on a high speed road course glow red after several hard laps of racing. Drivetrain: TKO 500 & TKO 600, and T56 close ratio are the best transmission choices

with your mild setup you can go a few ways

stock cam and 1.72 rockers
TFS1 or comp cams 258 or 262 cam and 1.6 rockers

yes. what injectors and MAF are you running . You can get away with 19# injectors but they will be getting near maxed out.

Pro-m MAF 75-80mm with the 24#inj and at least a 190# fuel pump(I'd go with a Walboro 255lph). Another cam option is an Anderson n41.

Get a cam from Ed @ FlowTech Induction along with a valve spring package. Just because the heads/intake are mild doesn't mean you are stuck with a stock or junk off the shelf cam.

You may need new pushrods(will have to measure to find out) and the rockers should fit(that also depends on what parts you use). If you're keeping the same cam everything should fit(but you have to check and make sure).

Grn92LX said:

Get a cam from Ed @ FlowTech Induction along with a valve spring package. Just because the heads/intake are mild doesn't mean you are stuck with a stock or junk off the shelf cam.

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You want him to spend $500 to get a custom cam and springs from Ed so he can get 20 more hp than an OTS cam? Don't see the need here.

mikestang63 said:

You want him to spend $500 to get a custom cam and springs from Ed so he can get 20 more hp than an OTS cam? Don't see the need here.

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I agree and I usually spout off about going custom myself. But with such a limited head/intake etc there really is no need. If the op wants to spend the money for it, it wouldn't be "wrong",but really isn't necessary. Any of those cams listed above would work well.

jlinmo said:

mikestangs63 would my stock computer handle the tfs1 cam ?

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I am running the stock computer with .613 and .588 lift,

I had the tfs 1 and n41 with my old gt40 combo, they both worked well. The previous owner installed the tfs1 with 1.7rr with stock pistons. It worked, but I have no idea what the clearances were.

Joe

mikestang63 said:

You want him to spend $500 to get a custom cam and springs from Ed so he can get 20 more hp than an OTS cam? Don't see the need here.

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Yep. About $100-$150 more than the junk dated recommendations listed here and well worth it. Cookie cutter parts = cookie cutter results.

Well he already has a "dated" cookie-cutter top end. Those cams listed for op's intended use vs custom isn't worth the extra money IMO. If it were a better topend...then sure. I'm positive Ed would have a better profile available but I don't see a drastic change in power available(20hp would be a generous guess IMO)

$100-$150 well spent plus the after sale customer service you get with Ed. I have no idea what peak hp gains can be had but overall you'd have a hard time finding a better deal for power per dollar spent with the extra $150 for a custom cam from flow tech

Umm I'm already running a custom. I agree with your general sentiment. But in this instance I feel there's very little to be gained. I like flow tech. I recommend them/Ed often. Just not with this type of build. If the op was asking about other "upgrades" AND a cam...different advise would be given. If the op wants to go that route(custom) he would be in good hands(Ed).

what o what did we poor idiots do before custom cams were around? $500 for a custom cam and springs makes no sense for this guy's mild build.

Yeah I'm one of those fools running one of those crappy OTS cookie cutter cams and with AFR heads and the usual bolt ons making 300rwhp through an AOD.

And for the record, I've used Ed on former builds when it was worth the money. You really think cam manufacturers haven't figured out these cars by now for 90% of the usual bolt on builds?

Trickflow stage 1 cam - $220 + say $200 in springs = $420. Cam from Ed about $350 and say $200 in springs (he needs springs either way) = $550. So appx $130 difference. The anderson N41 cam was another cam recommended. At $328.59, using simple mathematics it would cost about another $25 to do it correctly with a cam from Ed. Point I was making is yes it is worth it since it's very little extra cost to do it correctly.

Mike, what's your combo?

afr 165 heads with TFS upgraded springs and ford 1.6 RR - bought used for $1000
TFS 1 cam- new from Summit $200
Ford ceramic shorty headers- used $65
BBK 70MM TB, T Moss ported lower explorer intake $150 used
ProM 75MM MAF and Ford 30# injectors $150 used
SilverFox valve body $350
Taurus E fan- $30 used
usual other bolt ons exhaust, gears, CAI,alum radiator
Dynoed at 302 rwhp and 322 rwtq at Thunder Auto sports with Diablo tune. AOD's suck up 18-20% of hp so figure around 365-375 crank hp with mostly used and cookie cutter parts in a full weight convertible.

Feel free and tell how much hp I left on the table by not going custom cam for another $350. I chose to spend it on 4 hours of dyno tuning and a custom Diablo chip which picked me up 30hp and better idle and driveablity.