95 Cobra build suggestion?

**DRRummel** · 02-05-2009, 02:45 AM

I am going to most likely tear my engine down and rebuild it.
It is almost (if not completely) stock. Now I have heard the 94/95 Mustangs were persnickety about mods and the Cobra computers were even worse.

But I will have the engine torn down. So with keeping the Cobra intake, and ECU, what can I do to upgrade and still keep it running.

Will a CR increase cause a problem?
Will a different cam work much better then the stock?
Swap heads for a set of AFR 185? (this also forces a piston swap because of valve size)
I am not looking to swap a A9L and install a MSD. Not a stroker either, I hear it causes the computer to barf.

I understand the FOXs are so much easier to mod...

**venom** · 02-05-2009, 08:11 AM

ehhhh.

I had a 95 cobra back in 96 with heads, cam , & procharger on it. I had it tuned, and got rid of 98% of the computer issues. I would a surge at traffic lights here and there, stalling out from time to time, but thats to be expected.

Don't be skerd. Mod that biatch.

**Killercanary** · 02-05-2009, 11:15 AM

I can tell you that you are way more worried than you should be. I'll do my best to explain why the 94-95 EEC is different and that may help you understand why certain things will cause more issues with these cars than the fox's.

The 94-95 EEC is load based in its calculations. I feel the best way to describe load is to give an example of what effects it and how it increases. Picture cruising on the highway in 5th gear at a lazy 2000rpms with the cruise on. Then picture that the highway starts to go up a large and steep hill. Given the cruise is on the RPM's and vehicle speed are going to stay the same but the TPS will increase and the vacuum will go down as the throttle is opened to make more power to cope with the added grade in the road... thus an increase in load. In the 94-95 cars this has be figured out by the EEC by looking at TPS, MAF voltage, RPM, etc. Basically it would see that TPS voltage would increase as the throttle was opened, but it'd see that there wasn't much change in the MAF voltage and that the RPM's didn't go up as they both would given that same change in throttle position if the car was on a flat piece of road. This is how it interprets load since it can't determine vacuum in the engine.

The eec uses this calculated load for timing and fuel tables. Now what can cause issues here? Well first is a "recal'd" MAF will definitely cause some issues that must be tuned around since the MAF voltage is "tricked" in a recal'd meter and the 94-95 uses the MAF voltage to determine load. This can cause all sorts of problems if much larger than stock injectors are used or a poor MAF is used. I'd stay away from a C&L on all 94-95's since it only relies on altering the amount of airflow over the MAF wires to trick the EEC.

The other problem is a cam swap. When a cam "lopes" it changes the vacuum within the engine and since the 94-95 doesn't have a MAP sensor it gets sort of overwhelmed with the sudden increase in RPM and MAF voltage while the TPS voltage hasn't moved. I believe this is the cause for the surge and die syndrome and its also why most correct the problem with an idle bump to get the car above the "lope." There has to be more to it because some are successful in having the car idle at 700rpms loping just fine while others can not.

Strokers can cause some issues as the load calculations are based on a presumed 302ci. I remember in my eec tuner there was a line to actually change the CI of the engine and I assume this helps the EEC rescale its load calculations to account for the larger CI. This makes sense because there should be an greater increase in vacuum per movement of the piston than the stock 4.00 bore/3.00 stroke setup.

I hope that helps. A good tuner should have no problem tuning these cars so I say mod away!

As much as it sounds like problems with the 94-95 EEC this is actually a faster processor than the A9L, its just more sophisticated.