What's this "highway mode" I keep hearing about? Is it good for performance or mileage, or what? How do I get in and out of it, and is it available on an 88 Iroc?

thanks
steve

------------------
1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better

 

It consists of 2 parts (for the years that it's available): fuel and spark. It's strictly for mileage. The highway spark mode is usually disabled in most bins I've seen with the min. RPM set at 6350. The highway fuel mode was discussed in a recent thread with all of the details there. I'm not sure if your '88 has the fuel mode, but the '89 code definitely has it. If you're gonna be burning your own chips, might as well get the '89 definition file for whatever program you're using, then start with the ARAP bin (or the regular '89 350 bin) and go from there.

------------------
Greg Westphal
'87 IROC 305TPI/A4

 

Anyone else have any info that might help me?

------------------
1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better

 

If it's in the 89 code then how come I don't see it listed in the ARAP bin anywhere when I open it with Tunercat?

------------------
Black 88 GTA L98
261 RWHP, 345 RWTQ
13.406 @ 103.72 MPH
ZZ4 bottom end, Edelbrock 6085 heads, LT4 HOT cam, GMPP 1.6 RR's, ported stock TPI, SLP 1 3/4" headers, no cat, Dynomax cat-back, Stock PROM
E.T.F.A Member #11

 

because you need the updated 6E tdf file. Just email them and they will send it to you if you already purchased the old one.

------------------
355 10:1 , AFR 190 heads, LT4 HOT cam w/ 1.6 roller rockers, complete Superram intake, 58mm BBK TB, 24# injectors, screens out of MAF, MAT relocated, March underdrive pulleys, Streetdampner, Crane HI-6 ignition, 160 thermostat, K&Ns, TES headers(Jet hot coated), Mufflex 4' cat back, B&M shift Kit, 2500 converter, and 3.27s.

 

My rev 'N' 6E def file from Tuner CAT has like 10 different tweaks for the highway mode stuff...my old rev 'H' one had none of it.



------------------
GregF
87 IROC

 

I believe I saw Highway Spark in the 7747 TBI ASDZ hack BUT it is disabled...

Is it worth it for Spark alone??? Or should/can I just add spark in the Main Spark table at known MAP and RPM levels during highway cruising??? ie what is the benefit of highway Spark over said changes to the Spark table itself. Fuel table(s) I understand...

 

I just got TC about a month ago, has it been updated since then? I guess I'll shoot them an e-mail. Thanks.

 

OK nobody really answered my question - is there a way to activate it in my PROM? If not, where can I get a PROM for my ECM with it enabled and how much does it cost?
Wait a minute, what the hell is it in the first place? lol

------------------
1980 Camaro, '88 Police 350 engine, Headers, full exhaust, completely redone, my baby!
1988 Iroc-Z L98, MSD 6a, Accel coil, K+N's, Airfoil, Coolant Bypass, Flowmaster, Gears, Late model Bose, I like the 80 better

 

Your sig line says 88, do the hac at the ecm guy might give you some leads on where to go. Sometimes talks alot more work then then just typing a guestion to get an answer.
ie most folks probably are runnin a 6E program where your at a 32 or 32B, so it's less likely to get as detailed of info.,

 

The latest revision of GMEPro has a modified bin and includes highway mode.
The bits to it are at the DIY-EFI incoming area