RPMs: How low can you go?

[Cousinphil]

I took the Audi over to Mount Desert Island today, down along the quiet side of the island, through Pretty Marsh, West Tremont, and Bass Harbor. Bar Harbor is on the opposite side of the island which is the noisy side. The holiday traffic was heavy coming onto the island, many out-of-state cars heading for Acadia National Park. But on the quiet side there was hardly any traffic. I went through a little village called Seal Cove with about the prettiest stretch of road I’ve seen anywhere, with white churches, apple trees in bloom and the salt water inlets coming close to the road.





The Audi was running perfectly, the Michelins acting like they were glued to the road. I let go of the steering wheel a couple of times and the car went straight as an arrow down the road, neither pulling to the left or the right. This is a dream car. It doesn’t seem to use any oil.

Anyway, I’ve put about 10,000 miles on the car since I bought it, and I’m starting to get an inkling of just how low you can take the rpms and still have decent power. This 1.8T engine really doesn’t like to go below 2000 rpm. At 1500 rpm in third gear, if you tromp on it, you’re going to hurry up and wait. If you floor it at 2500 rpm in the same gear you’re going to be pinned back in your seat. So what I’m wondering is, if I get a custom tune for this car, is it going to pull any better at low rpms? Is the power going to kick in any earlier?

[MoparFreak69]

Welcome to turbo lag. Not much you can do to gain that down low power with a small 4 cylinder. Unfortunately that is just how it is. It gets worse with a bigger turbo.
A tune will help slightly, but not much down below boost thresholds (2500-3000RPM).

[jesse500]

Cannot really add anything other than exhaust components, to help spool time. A tune will definetly help with how hards it pulls, I am stage 2 tune, at 21 psi peak, where stock is 10-12.

But a nice 2.5" downpipe back exhaust, and catless downpipe/3" HFC will help spool time. Mine comes on around 2200-2300rpm. (6 speed).

A good tune though makes the car feel way better. Runs smoother, better on the highway in 6th, feels way more efficient. And 40+ hp difference is majorly felt.

Get yourself a 3" HFC (high flow cat) or 3" test pipe, and a Stage 1/1+/2 tune and you will enjoy car alot more.

[G-Ride]

e85 and a lot of timing helps.

[diagnosticator]

The stock boost is specified as ~11 psig from 1950 to peak torque RPM, a flat line on the graph. A 2.5" down pipe with a High flow cat will help the turbo spool up at low RPM to increase low speed torque. Skip the ECU tunes. That won't help lower RPM torque.