Geoffrey

FWIW, On my 930, I have a set of 321 stainless headers made by MODE engineering in the late 80s, so they are AT LEAST 15 years old. I finally had to TIG weld them each year for the last 2 years. but it was around the heater box attachment to the primary tubes themselves. I also made a better hanger for it which was necessary with the larger heavier T66 turbo. I believe these headers were $4000 at the time, well worth it in my opinion since they lasted on a car that primarily saw track usage 20+ days per year for the last 6 years or so.

SGOGT4

Stephen / Kevin -

I finally got a chance to take the 930 out on some empty stretches of highway. Funny thing is happening. As the tach climbs past 5,500 RPM the car begins to stutter. The car is definitely running harder with the HFS because I continue to maintain .9+bars straight thru the RPM range where as my 7200 dropped off pretty dramatically right around this same point.

Is this something that you have seen before?

I am running 3.3L, Garretson IC, Tial Waste Gate (1B equivalent less helper spring), B&B headers, K27HFS, Andial Fuel Enrichment, and Borla Exhaust.

ANY suggestions would be MUCH appreciated as this was not occuring prior to the turbo upgrade.

Thanks!

Kevin

How are your spark plugs.. Check them.. Plug wires? Is your overboost switch in effect? What kind of boost gauge do you have?

SGOGT4

I have a secondary vdo boost gauge in place of the clock. Are you thinking that this could be something as simple as plugs or wires? By overboost switch do you mean the overboost relay?

Thanks for the quick reply...

diabolos88

I know Im reviving an old thread, but I am curious as to what caused the stuttering to 930LDR's engine under load?

nathanUK '81 930 G50

It's usually the plugs, wires or the overboost safety switch.

diabolos88

Im a newbie, whats the overboost safety switch? wheres it located?

SGOGT4

Ended up being plugs/wires

A930Rocket

930LDR,

Did you go with stock plugs or something else?

SGOGT4

Stock plugs... my original ones were all crapped up.

nathanUK '81 930 G50

If you have short neck IC then it is in the left handside of plenum chamber/bypass assy.
If you have a long neck IC like my Kokeln then it screws into the IC.

It is just a pressure switch, NormallyClosed, no resistance. The boost sender gives a resistance for the boost gauge and is bigger than the switch.

diabolos88

Im thinking of swapping my Andial IC for a Kokeln since it is bigger. Im living now in Arizona and any additional cooling is a plus. Its not even summer yet and its already 90+ here. talk about sluggish turbo performance

jimculp

I'm adding a B&B front oil cooler to my car in addition to the B&B IC to try to keep things cool and offset some of this North Florida humidity.

A930Rocket

Should be one the one with the red boot.

Rob S

Actually, the overboost safety switch is in the red box on the left. The one in the red boot is the sending unit for the electric boost gauge. I've never seen a gauge sender with a red boot before. Is that the way they came from the factory?