Best/Worst decision when ordering SPF MKIII

[Lowell W]

I can't help you with the gearing or the tires, but you raise an interesting point with the carb vs. injection question.

I have a mild (530HP) 427W with a carb and really don't have any driveability issues once the motor is warm enough to idle, which only takes a couple of minutes. Part of the Cobra's appeal for me is its simplicity and the fact that it is more "owner serviceable" than a modern car. It would lose some of that appeal with FI, simply because a problem would be more difficult to isolate and rectify, especially on the side of the road in the middle of nowhere. On the other hand, once it's set up and running, a motor with FI might run trouble-free forever.

Lowell

[cobrasnake]

I ordered mine with no fender mount mirror as they are pretty much useless. I mounted my Raydots on the windscreen with a bracket similar to what Finishline sells.

I like my smaller leather wrapped wheel - easier on the hands and turning - not as authentic looking however.

I have a Roush 427R - almost 10K miles. Cam sounds great but terrible mileage (10± mpg). Had a Holley 750 but changed to an 870, mileage went down (duh) but eliminated a stumble around 2K RPM. Dual plane manifold. I understand Roush is working on a 427SR which is suppose to be more streetable - you may want to look into that if you aren't looking for maximum HP/TQ.

Seat heaters if you want to keep your co-pilot a little warmer or go for an electric blanket.

Great car!

[greg schroeder]

For what it's worth......

I'm real happy with my Roush 427R-095, single plane manifold, Pro-Systems carb, 2 in. primary Olthoff headers, taller air filter on maid in Taiwan Cobra look air intake. It has zero street driving problems and is smooth as silk. It's also almost as quick as you're going to find on the street from a standing start to about 100 mph with the MT street drag radials. I picked up a second set of 17 inch wheels with Yokohama A032R soft compound tires and another road course carb from Pro-Systems too.

I have the 3.73 8.8 Ford rear end with Tremec TKO 600. The 4th gear and that rear end on 28 inch tires is just about perfect for a 1/4 mile and it runs like butter through the gears around town too.

If I did more I'd use different side pipes with interchangeable mufflers, larger fuel line/fuel delivery and a little 50 HP wet shot and stronger splines for the half shafts on the rear end.

If I had to choose between having all changes above or fuel injection on a base car I'd go with the above. Just my opinion.

Here's the general shift points and performance from an off idle start of how I have the car now. It's not the best run, but repeatable in our Arizona winter months.

[jmorganw]

Greg,

Thanks for the info. Looks like you get close to 50 in first which is about where I feel I want to be. I am a little surprised you rev to 6500. The Rousch site states Max RPM 6250. I am planning to have a rev limiting ignition and thought I might limit to 6000.

What sort of rpm do you have in top gear at, say 70 mph?

Can you tell me something about the headers? I seem to understand that the standard ones don't quite match up with the engine. Don't know what the diameter of the standard headers is.

[greg schroeder]

Originally Posted by jmorganw

Greg,

Thanks for the info. Looks like you get close to 50 in first which is about where I feel I want to be. I am a little surprised you rev to 6500. The Rousch site states Max RPM 6250. I am planning to have a rev limiting ignition and thought I might limit to 6000.

What sort of rpm do you have in top gear at, say 70 mph?

Can you tell me something about the headers? I seem to understand that the standard ones don't quite match up with the engine. Don't know what the diameter of the standard headers is.

I use a 6800 rpm rev limit. It over revs now and again to around 7000 as I'm all fired up going through the gears. From what I understand not all cam specs are the same in each 427R. Roush has declined to give me my cam specs. I have 427R-095 which seems to pull great up to 7000 rpm with the Pro-Systems 1000ish cfm carb.

Here's the RPM page from the above run. There was some wheel spin at start so that's why it looks choppy in the beginning. The tires on rear are Mickey Thompson ET Street drag radials, 325/50 15. They're not actually 28 inches tall as their site says, but rather about 27 inches.


My Superformance small block headers covered .3 inches of width on each exhaust port for the heads on my Roush 427R-095. The height of the Superformance header opening is too tall. The heads are AFR 205s built for Roush. The headers I got from the Olthoffs were 900 dollars and have a slightly larger diameter than the AFR 205 exhaust port. They look just like the Superformance headers, but are 2 inch primary instead of 1 7/8 and have a new flange welded on then re-jet coated. I aligned the pipes to heads even on the bottom with the over size at top to more center the highest exhaust volume location within the exhaust port below the bend in the pipe at top.

I don't recall my RPM in 5th gear at 70, but it's quite comfortable with the .64. The 4th gear is a 1.0.

My side pipes are on order from Buckshot Racefab.
http://buckshotracefab.com/

My new half shafts are coming from the Drive Shaft Shop in a few days as I shattered the splines on one in the left side in the differential.
http://www.driveshaftshop.com/

I'm putting on a larger size fuel line for the mechanical fuel pump that came on the Roush 427R-095. I may buy a 130 gph pump with regulator next if I do a 50 HP wet shot Nitrous oxide system.

[jmorganw]

Thanks again Greg,

I am not a mechanic so some of these things are outside my ability, but the headers are not, and while I want to have "bragging rights", I may never fully utilize the power.

I looked up the carb company, Pro Systems and will investigate that too. I do want power, but since I will not be going for the max I am really interested in drivability first and power second.

[Bill Wells]

jmorganw :

the Pro Systems custom carb gives you BOTH driveability and power. i recommend them for street cars never expecting to see the strip or track , as well as the racer folks. their carbs are superb outta the box :

see ; http://www.pro-system.com/

they have built two carbs for me for 2 different applications....excellent all around performance, and mine are without chokes yet start right up -even after storage. bill