Let's take a fast forward into our Non turbo build that will be happening in the next few weeks. So many times non turbo owners jump on the forums and ask what they can do to improve performance and power and are met with the old stand by answer, “Sell it and buy a turbo”. While this advice may actually be well intentioned, and possibly the best option for a high powered build, there are still ways to improve the performance of these non turbo models. Our scheduled build is intended to be very approachable to the average owner with off the shelf parts and tuning of our 1995 Volvo 850. So let’s start by outlining the build and talk about what we can expect.
First things first, not all non turbos are equal. With regard to the 850 chassis primarily there are two fuel systems used in the non turbo models. From 1993-1994 the LH 3.2 Fuel system was used and can be easily identified by the use of two ECU’s to control the engine, one for fueling and one for ignition. Later 1995 and up models used only one ECU as Volvo switched to Motronic engine management version 4.3. The earlier systems are harder to make gains with since the rudimentary LH system is not exactly brimming with technology that can be easily modified for power gains. So for the rest of this article we’ll focus on 1995 and later cars including the Denso fuel systems that were used in non turbo cars starting in 1999.
Tuning
I’ve started tuning the car already just to get a sense of how hard we can push the timing advance in stock form by simply taking advantage of the improved gasoline quality that is available day by day at your local gas pump. The added ethanol and other additives allow us to add as much as 6 degrees timing advance in spots on the ignition map. The fuel and ignition calibrations from a car that is nearly 20 years old are unsurprisingly out dated with respect to today’s fuel content and quality. This translates to a much peppier car coming of the line and down the midrange. With some added enrichment I think we can provide a very notable increase in power. Granted it won’t be quite as considerable as the 30-35 bhp we can so easily attain with tuning turbo models but should help scoot us down the quarter mile drag.
Air intake
The plan for the air intake is to swap out the original long runner 850 manifold for a shorter runner ME7 manifold from a later 1999+ car out fitted with a 70mm throttle body and K&N Shrouded intake. This along with some cam timing and tuning should bring the power band further up the rev range where it naturally tends to fall off. This is in hope to spread the power over a broader section of the RPM range which will help get us down the track more quickly. Shorter runners are more desirable for taking advantage of intake wave pulses at higher RPM’s which can promote dynamic cylinder filling that exceeds 100%. Sort of like turbocharging but without the turbo.
Exhaust
For this one we’re going simple, high flow OBX header and a cat back system from the turbo cars as the piping is larger diameter and freer flowing
Ignition
The folks at Eurosporttuning.com were kind enough to donate an MSD coil kit for our build. Thanks to Frank for offering to be a part of this! We’re running Bosch Motorsports plugs even though these are overkill for this setup, but they needed replaced and we had them on hand J The remainder of our Stage 0 maintenance has all been completed including cap/rotor and wires.
Misc
We’ll add on the ARD light weight crank pulley just to help shed as much unnecessary weight as we can as well as remove the 5lb resonance block under the center console (You can see the yellow weighted block in the picture below)
We’ll leave the spare and jack in the boot since that’s an everyday item we all would normally travel with.
We’ve got all our parts in hand and we’ll be heading to the track first though to get some baseline data on the car in stock form and also stock plus a tune. Then the following week it’s install time and all the go fast parts will be installed and tuned for, then we’re back to the track to see if we can make this little green monster go!
Robert Lucky Arnold
ARDtuning.com
It's testing time for this weeks Fast Friday article and we're back from the track on part 2 of the non-turbo build. To recap, last week we outlined our plan for tuning and parts upgrades for the 1995 850 non-turbo automatic that we've chosen as our test mule and this week we'll be reviewing our preliminary data on stock performance as well as how the car performed with no parts upgrades and just tuning!
I'd like to start out by saying thanks to Kyle E. from the V shop for being our driver during our testing. Kyle has more time on the track than just about anyone I know and he's well known in the local scene for the work he's done on his non-turbo 240 as well as his consistency on the quarter mile. He's the perfect candidate to provide feedback during our testing and provided some great input during the runs, thanks Kyle!
To Begin... Weather
When we arrived at the track weather was not looking good and we got caught in a few sprinkles that seemed to threaten the evenings events for sure.
However after a 30 minute wait, the weather cleared, we got the go ahead from the tower, and we lined up on the grid! The first run put down a surprising 17.16 second run with a 2.55 60 foot time. Not too bad for a bone stock 225K mileage automatic transmission 850. Thanks to Kyles consistent launching the second attempt (also bone stock) ran a 17.14 with a 2.67 60 foot time. If nothing else this little machine is consistent and these were the kind of numbers we were hoping to see in stock form so far so good!
Prior development
I'd be driving the car all week doing some road testing and had gotten what I thought was a pretty solid tune file. Midrange was really snappy compared to stock and the fuel economy had even increased by 3 mpg quite consistently. The car was much more enjoyable to drive and with some considerable addition to the part throttle timing maps I was surprised how well the car behaved. With this in mind I really expected to see some decent time shaved of the quarter mile ET but I was in for a bit of a surprise, and not the good kind --
As you well know in a quarter mile drag the throttle control for a lower output engine, aside from the launch, is essentially foot hard down all the way. However that's not the way we typically drive cars on the street -- at least I hope not. I had spent considerable time in mid-range tuning which had netted a clearly improved power output and efficiency but when I translated this to the wide open throttle maps I had over advanced the timing such that the ECU was hearing mild detonation and in turn we suspected it was pulling timing back. This reduced power and left us with our first tune run at 17.23, actually slower! After a second run at 17.31 we knew for sure the ECU was retarding ignition timing and we needed to go back over the WOT timing curve.
Redo
We were running out of time but I wanted to at least get some type of gain from tuning as I knew there was some room for improvement over stock mapping. Starting from scratch I free handed the timing map for WOT and re-curved the enrichment map for fueling. Without my ignition angle calculator I had to work the ignition advance in my head quickly as we were realistically were only going to get one or two more runs in before the night was over. With that done we loaded the ECU and sent Kyle back to the grid!
After the first run we saw some improvement but Kyle felt he could get a bit better launch and get us into the 16' so he went back to the grid for one last run. With an excellent launch and a better timing map we saw a 16.91 with a 2.53 60 foot time. Not astounding by any means but it proved there was room in the tuning for improvement even if we only had time for a quick remap in the pits.
With more time and testing I think we can get the ET down to 16.5 and if time permits we'll be testing again this Saturday. We'll ideally plan to just tune on Saturday with some adjustments to cam timing while were on site. Then during the following week we'll install all our hard parts and finally return the week after for final runs down the track!
Retrospect
I realize the numbers on this build aren't the most exciting and of course the experience at the track was one that incurred some learning that partly slowed development, but I've come to find these happy accidents are just that --. something unintended but not necessarily undesirable. With that in mind I'm excited to continue the work on this and see what else we'll learn as we move forward. I hope you'll stay with us as the saga continues!
Robert Lucky Arnold
ARDtuning.com