cbracerx

Greetings,

I recently purchased a custom software service for my 993 RS 3.8 engine (it is pretty close to that model in spec, see below):

964 1990 Stock Valve Heads, heavy springs from DRC
964 1990 Stock Crankshaft
964 RSR 3.8 Lightweight Pistons
Lightweight Connecting Rods
DRC DC20 Camshafts
993 HE w/no-cat free flowing (loud) exhaust (has single 4 wire O2 sensor)
US 993 Varioram Intake (1998)
RSR Flywheel, PP and RS Clutch
55 Pin socketed chip DME.

I got the baseline chip, installed it and took two drives yesterday. Car runs very well as is, certainly more spirited at WOT than the stock 3.6 v-ram chip I was using. Will make arrangements to gather the A/F data soon.

Did have an issue though – after a few runs near redline (6700 ish) the rev limiter started to kick in at 5800-5900! I confirmed this a few times, then cycled the ignition – rev limit was back up somewhere near 7K (I did not try and push it over 6700).

After speaking with the software manufacturer, this was described as an occasional issue with ROW Variorams. Ouch. Does anyone have experience with solving this issue? Any thoughts on the real root cause?

For a while there, I was really happy to start to see the engine run more at its potential, but this is a bummer!

Thanks!

cbracerx

Let me add this question - is anyone selling the ROW software for the 993 RS that runs without any random rev limit reductions?

Geoffrey

Not to be a pain, but your engine as listed differs in some key areas from a true RS engine and the mapping will likely be off. The 146cc displacement increase is only a minor change between the stock 3.6 engine and an RS engine. The breathing improvements from the RS manifold, camshaft profile, heads, and valve size is fairly significant.

BTW, the RSR pistons are not lightweight, they are heavy at 541g without pin or rings.

Monique

FWIW, the redline for the 3.8 RS engine is 6980.

No. I never had any issues with limited RPm throughout.

Manthey Racing near Nurburgring may answer your question.

Go to Kontact. They will answer your question.

http://www.manthey-racing.de/

They maintained my car before I bought it and answered many questions. But I did the wrenching myself...

cbracerx

Geoffry,

Differences noted, although my pistons weigh 417 grams without pins (98g) and rings.

My request for this programming is not to plug and play, but to get a decent baseline so the chip can be further custom mapped on a chassis dyno. But it will not be much of a baseline with a 5800 RPM redline!

cbracerx

Do you have a suggested vendor to help cure this?

Bill Verburg

Geoffrey is first and only a Motec man

That would be a good albeit expensive way to go.