Another ECU question

[LaserGurl]

hey guys!

I recently got an 86 shelby charger to play with. The motor is pretty well shot, but I have another motor from an 85 lebaron T1. I just ordered a 86 stage 2 ECU from FWDPerformance. Did I screw up? Will I have to have an 85 ECU to run the lebaron motor? Would it be easier to swap the head and distributor and such to the 85 motor?

Ive been searching the site for info, but havent come across exactly the info Im looking for. Any help would be much appreciated!

Thanks guys!

Tifany

[t3rse]

Yes and no....

The 85 probably has a G head: casting number 4323287

The 86 + is probably a swirl head: casting number 4105782

The swirl has a smaller combustion chamber meaning higher static compression, which means to accomplish the same HP as the G head it needs less timing. This means that the cal you ordered will have less timing programed in and will cause you to lose power. The distributors are the same.

The second reason I think it was not wise is because every car likely has different parts: from different length and diameter charge pipes to different intercoolers to different turbos etc. This makes it hard for a vendor to come up with a universal cal. There are plenty of competent people here that could burn you a cal for your specific needs at a comparable or cheaper price.

However, your car will probably run fine with the cal as long as the boost isn't a ton higher, else you will most definately need an intercooler, it just may be down on power slightly (from where it could, not should be).

I've never met a Tiffany spelled with one f; welcome!

[daytonaturbo87]

I would send it back and exchange it or tell them to recailbrate it for a G head calibration. The G head flows better than the swirl head and therefore requires more fuel, and it requires more ignition timing than the swirl head. G head on a swirl calibration will likely cause your car to be down on throttle response during normal driving. IMO you're better off just getting the correct calibration for your car.

As far as t3rse's point about every car being different and no universal cal being perfect, I totally agree. But an adjustable fuel pressure regulator and a wideband o2 to tune with will get you the rest of the way past where any universal calibration falls off. Ignition timing isn't as easy to tweak as adding a little extra/less fuel tho.

You could put the swirl head on your car, but beware it'll increase your compression ratio. 85 uses different pistons than 86+ and combined with the swirl head having a smaller combustion chamber than the G head is why you get the increase in compression ratio. Increase in CR is no good for boost. IMO much easier just to get the correct calibration for you motor rather than tearing into it needlessly.

[LaserGurl]

Thanks for your help guys!

I think im gonna exchange the ECU for one cal'd for a G head then. I have an extra ecu that I may play around with a custom cal once i get this thing back on the road again. I saved this shelby from the crusher and unfortunatly she needs a lot of work!

You guys are awesome! Thanks again!

Tifany