SN94/95 owners - need your help

[Michael Yount]

I've got a friend in England who wants to modify his AC-Ace, and British sports car powered by a 94/95 era 5.0L/5 speed. At this point he simply wants to upgrade the exhaust, the throttle body, the intake manifold and the heads. He's planning on a set of 1 5/8ths shorties and downstream exhaust upgrades, a 65mm throttle body, a trickflow upper and lower, and a set of AFR165's. He has EXTREME emissions/inspection issues over there - so he wants to keep mods relatively conservative so that he won't have any problems in that area. For now, he's planning on sticking with the stock 70mm maf and 19# injectors, although he may have to upgrade the fuel pump. Cam will also remain stock.

His question is this - will the 94/95 ecu tolerate those changes ok? He's heard that he'll need a chip or twEECer even with those relatively mild changes, and I simply don't know enough about the 94/95 ecu to coach him. So, you guys get to educate me. Shouldn't he be able to bolt those on and see a pretty significant power/torque increase across the board, without any drivability issues?

 

[wytstang]

I wouldn't think it's going to be too bad. It when you switch out the cam is when the computers freak out (too much duration or too little). He will see a nice gain from the heads and intake that's for sure. Any drivability issues "should" be able to be worked out with out a chip or twEECer.

 

[VibrantRedGT]

He keeps the stock cam then he's fine.

 

[mootang]

if you look in my garage i have a very similar combo and i don't have any problems with it.

 

[RIO5.0]

I would have to stick with Vib....The cam swap seems to be the biggest problem...You can run all those mods and things will be fine, add a cam in there, and let the games begin..Least that was my expierience....

19s??? I dont know for sure on that one....I know with my mods the 19s kept the AFR right in the sweet spot...I was gonna do 24 but stayed 19s just for the info on the AFR...He may be "maxxing the 19s with those H/I ??
I still run a stock EEC and will pull 0 codes...so the EEC is not as bad as some say to me. I have had nil for problems...I have all my smog gone to...If he runs all the smog and cats, i'd dare say he'll do all right...
I run a Pro77 and have had excellant results...he's gonna run the stock 95 MAF??? That could be an issue with the airflow he's gonna be pulling??I would prolly add a nice MAF on the list....

 

[Michael Yount]

Thanks guys - this'll bump it back up. Others with similar mods?

 

[Killercanary]

Michael, I agree with the others. If he sticks with the stock cam he should be fine.

JFYI- the 94-95 EEC is a LOAD BASED EEC unlike the A9L that is more of an RPM based EEC. The problem with this is that the MAF is what the EEC uses to determine the load (along with TPS and such). So, in addition to a cam swap, a recal'd MAF can sometimes cause some issues since its sending a "tricked" voltage to the EEC and therefore load isn't measured exactly. For most of us, the cam is the problem, but often you'll see people with MAF related idle problems as well. Although some get away with a C&L, many experience problems and I believe this is due to the use of metering tubes that are pretty particular to air turbulence and such more so than say the electronics in the pro-m stuff. Hope that helps some...

 

[Michael Yount]

Thanks canary - actually, the maf-related drivability/idle issues aren't limited to the SN94/5 ecu, as you might imagine. But that's why I've coached him to stick with the stock maf and injectors. I believe they're sufficient to manage the increased air flow he'll see with the parts.