2000-2700rpm surge

[Rowdy]

Alrighty.. so after the mods I started to notice this surge.. Its not EXTREME but it happens at part throttle from 2k to 2700rpm with a little bit of load. Quite annoying..

Now, I sent a couple logs off to Jon and Terry to see what else is up. Sounds like the car is pulling timing.

I've got 50/50 mix in the meth tank.. running either 92 Octane with a booster or 94. I double checked all the wiring connections. Watching the hijacked gauges I get 100% meth flow and in 3-4th gear it shows 16-17psi..

Anyone have any thoughts? Mods are as follows

VRSF stepped core intercooler, AR charge pipe, JB4 ISO, BMS meth kit. BMS catless downpipe RPI quad exhaust and a K&N drop in filter.

Went to the track last night and went a best of 13.3@108mph with a marginal 2.1 60ft time. Certainly a bit more practice and I could get a 1.9… but still! That just doesn't look right based on weight and trap speed.

[Freon]

"Surge" is a pretty specific diagnosis, and I doubt that is your issue. It's a word people like to toss around, but is almost never the issue.

You probably just have knock and the ECU is reacting by pulling timing and/or load (boost), so you feel hesitation. Start by replacing all your spark plugs, then you can try chasing down coils or injectors, or carbon cleaning.

[Rowdy]

Its not a hesitation. Its an oscillation when steady throttle at low openings. Sure surge sounds specific.. but that was the easiest descriptor.

I highly doubt it's cylinders that are carboned up. What with the water meth and the BMS catch can from new. You're right though. I will check the plugs and I know from the logs that it's pulling timing at WOT. Makes me wonder if it's got a bad coil…

[e36addict]

I know your problem, my car has done it since I installed JB4. ISO 5_3 seemed to help a bit at first but it's still very annoying. If I run it stock boost map 4 it no longer does it... So i've just lived with it.

[Grinchxvx]

Is your car really jumpy or snappy with the throttle? My car was doing the same thing and turns out my menu 10 and 12 settings were messed up so I reset all setting to default and now it's good

[Rowdy]

I haven't tried map4.. but 1,2,3 and 5 do it.

It happens at steady throttle with a light load between 2000 and 2700rpm. It literally sounds like an oscillation. Its not jumpy or snappy with the throttle..

[Rowdy]

Changed the DWM to 20 and sure enough its gone. Now to slowly bump it back up so it's not super laggy!

Also.. changing the plugs.. the two I pulled look haggard

[Grinchxvx]

Originally Posted by Rowdy

Changed the DWM to 20 and sure enough its gone. Now to slowly bump it back up so it's not super laggy!

Also.. changing the plugs.. the two I pulled look haggard

Did you change them back to stock or to something different? I would still just reset everything