Unique or ERA 427 Cobra build

[mrmustang]

Originally Posted by MGP69stang

Cobras are light so ..What is the HP sweet spot for the 427 Cobra ? 450-500HP ? Controllable trackable HP range ? Sticky Tire recommendations ?.. high wear not a problem.

For the street, 400-425hp is more than enough, anything higher, and you'll deal with a car not very street friendly.
For the track, if you are serious about racing, 500-600hp is about right

Bill S.

PS: Keep in mind, 200hp is enough power in a Cobra to kill you. No anti lock brakes, no computer controlled engine management, not anything like you have driven before, not even if you race formula 1 or Nascar as has been noted before by owners who did.

[MGP69stang]

Yep.. planning on around 450-475.. I heard there is a 427 build thread that is about more torque and street-able power.. does anybody have that link ?

[patrickt]

Originally Posted by MGP69stang

Yep.. planning on around 450-475.. I heard there is a 427 build thread that is about more torque and street-able power.. does anybody have that link ?

There are numerous threads on that issue. Any builder of an FE can get you those numbers and higher without batting an eye. But, if you are going to be driving your car predominantly on the street, and sometimes in traffic, then your engine builder needs to know that so that some manners are dialed in at lower revs.

[Buzz]

There's also a school of thought among experienced Cobra owners that says don't skimp on the horsepower on your initial build. If you're a capable,sensible and responsible driver and also enjoy fast, powerful cars; you soon get used to a mildly powered Cobra. After a while, you end up wishing you had more for that adrenaline rush when you (gently) mash the throttle in an appropriate setting.
A stroked big block or even a big-inch Windsor can make 550+ docile, streetable horsepower easily without revving to the moon and just because you have it doesn't mean you always have to use it. Practice judicious self and throttle control and I promise you the car won't suddenly fly out from under you and go skidding across the highway. For those who simply cannot grasp that the right foot controls the power, there's plenty of used Miatas out there that will absolutely refuse to break the rear end loose unless you're driving them on ice.

[MGP69stang]

Also on a tangent.. I know automatic transmissions are sacrilegious but still thinking about C6. I was researching and the C4 transmission is a smaller footprint and might not require making the tunnel much larger than for a Tremec 5spd. Summit , Gearstar and others make performance C4 that can easily handle 427 power

[patrickt]

Originally Posted by MGP69stang

Also on a tangent.. I know automatic transmissions are sacrilegious but still thinking about C6. I was researching and the C4 transmission is a smaller footprint and might not require making the tunnel much larger than for a Tremec 5spd. Summit , Gearstar and others make performance C4 that can easily handle 427 power

Look, unless you are handicapped in some fashion DO NOT put an automatic transmission in your Cobra. It will gut the value of the car and other Cobra owners will snicker and point at you behind your back.

[MGP69stang]

Lol ..ok

[twobjshelbys]

Originally Posted by mrmustang

For the street, 400-425hp is more than enough, anything higher, and you'll deal with a car not very street friendly.
/

Which is why a 289 small block Cobra is better suited for most Cobra owners. After having the 550HP SBF 427 I speak from experience. The down side to a big displacement lopey cam engine is that it's simply not happy running at low RPMs. If you have a Tremec 5 speed you'll find yourself in 3rd or 4th most of the time to keep the RPMs up a little.

[MGP69stang]

The FIA body is proportioned well between slabside and the 427. FIA roadster body with no rollbar , exhaust out the back and a hood scoop(blended into the hood) wood be very sweet. A true 289CI, TFS, webers, Tremec TKX.. Damn !

[Sargie]

Originally Posted by MGP69stang

The FIA body is proportioned well between slabside and the 427. FIA roadster body with no rollbar , exhaust out the back and a hood scoop(blended into the hood) wood be very sweet. A true 289CI, TFS, webers, Tremec TKX.. Damn !

I’ve got an ERA 289 FIA car with a 331 SBF & webers. Carbs don’t like low rev driving. Need to keep the revs up 2,800 -3,000 minimum to run smooth. Love the car and wouldn’t change a thing. At about 420hp it’s all I’ll ever want far more than I need. The small block is good driving balance in these small cars.

[RUFdriver]

I agree 400-450 is plenty of power in a Cobra, probably a lot easier to drive on the street. Just start with a good base and you can always add more power later. Smeding and others can build a nice 427 stroker in the 450-460 power range, powerful motor with a mild cam.

[PDUB]

Originally Posted by Too tall

6'4", 230lbs. Visited Unique in Gadsden, Alan told me his son-in-law was 6'4, and I painfully drove the son-in-law's car. Excellent folks -- I wanted to do business with them,

I believe that car is one of the older setups from before they lengthened the foot boxes, which, if memory serves, was in early 2010, as I got the first one. There is more room in them, now. I encourage MPG to make a visit to Gadsden to check it out for himself... it's the only way to tell definitively.

[Harpoon PV2]

Did you snicker behind old Carrol's back? He owned a few auto Cobra's! His last ever was a CSX8000 MKII with an automatic!

[CSX2345]

I have an ERA 289 FIA as well.

427W Keith Craft with a Holley 750. Perfect combination of small block weight and size with big block HP and TQ.

Great daily driver with no issues in traffic.

And yes I drive it to work when it's 100+ in AZ, stays right at 180deg. all day.

Cheers

[w-lewis]

I have a Unique and can attest to everything already said, especially the recommendation to visit their shop in Gadsen. You won't be disappointed.

[RockBit]

Very sage advice from Buzz in post #64.

I have a sideoiler built by Brent Lykins. I asked Brent to make it streetable and perform well at 2000-4000 rpm with a broad flat torque curve. It dynoed at 580 hp and 659 lb-ft, and I have no problem with it from stop light to stop light. It has a great lopey idle.

Unless you specify good street manners, most engine builders will give you something that is more suited to running flat out on the track. You will then be changing the cam to try and detune it.

Since you live in Florida, get the big cooling option, and don’t use an oil cooler. Mine is plumbed for looks but not used.

[w-lewis]

Mine has an oil cooler and I wish it didn't. My oil temp seldom gets my hotter than 175.

[twobjshelbys]

Originally Posted by w-lewis

Mine has an oil cooler and I wish it didn't. My oil temp seldom gets my hotter than 175.

Which also affects the water temperature. My observation is that the huge radiator (if it's the usual Fluidyne) and oil cooler the engine is "over cooled". The engine never really gets to a good operating temperature. If you get an oil cooler at a minimum you should get a thermostat. Some just put it in but don't plumb it to fill the hole in the front. I went to a higher set point thermostat but had I kept it another year would have put in a oil cooler thermostat.

[Buzz]

Originally Posted by w-lewis

Mine has an oil cooler and I wish it didn't. My oil temp seldom gets my hotter than 175.

Interesting point. When I was in the process of ordering all the parts for my rebuild, Alan Weaver at Unique advised me not to add the customary oil cooler. It turned out to be sound advice - many years of driving in consistent 80 degree plus temperatures and my oil temperature was always perfect.

[mrmustang]

Originally Posted by twobjshelbys

Which also affects the water temperature. My observation is that the huge radiator (if it's the usual Fluidyne) and oil cooler the engine is "over cooled". The engine never really gets to a good operating temperature. If you get an oil cooler at a minimum you should get a thermostat. Some just put it in but don't plumb it to fill the hole in the front. I went to a higher set point thermostat but had I kept it another year would have put in a oil cooler thermostat.

Both of my Cobras see consistent coolant temps in the 185-195 degree range, oil temps in the 180-190 degree range. Has a lot more to do with humidity levels coupled with the 80-95 degree temps we have here in the upstate of SC. The FIA has an oil cooler, the 289 roadster does not. Both have a 50/50 mix of coolant, with Amsoil "Dominator" coolant additive. Temps are consistent whether at highway speeds, or around town.

Bill S.