#project86 - E85 tune
Just over 8 weeks ago now we sent #project86 off to PVS tuning for a flex fuel tune on our SME equal length headers and HKS drop in panel filter we installed. Now to get the max potential gains we should have thrown a front pipe and catback in as well but the budget just didn't allow it at the time.
The flex fuel kit is the Zeitronix unit from Pro Speed Racing that we fit ourselves before taking the car into PVS. The gauge is mounted to the air vent via a 3d printed mount. As mentioned earlier we are using SME equal length headers and a Tomei overpipe. Everything behind that is stock for now.
We spun up 132kw @6500 rpm and 221Nm @4820 rpm on the PVS Hub Dyno which for those in the know is about the number you would expect with a full exhaust, intake and 98. It seems as though E85 is the great equaliser on these cars. Want some power and torque on a budget? Throw some headers on and get an E85 tune and you’re off. Got abit more of a budget and want the simplicity of 98? Full exhaust, intake and a 98 tune and you’re making the same power. If you have a budget and happy to live with E85 and you’ll see 140+ KW which is awesome in these little cars.
The green line is with the E85 tune. You can see that the car accelerates out of the hole better and also hits higher top speeds at every point. It’s worth noting that you can see I was actually driving better on the day of the 1:10.1 as the 1:09.3 (E85) was done in an afternoon session whilst I was at work. The added power masked this poor driving and still gave us a better lap time.
The first video below is after the E85 tune. The data shows a mid-high 1:08 which i’m very keen to have a crack at when we can get back to the track. The second video is before any tuning. The only lap I got a on GoPro was a 1:10.4 however the laps were very similar. I lost the 3 tenths at T2 in this video.
Now, was it worth it? Absolutely it was. I gained a little under a second at Wakefield Park after the tune with most of that time coming from up and over the hill. The gain down the straight was only 3-4kmh which is alot in a low powered car but most people could find that speed purely with a tweak to their exit of t10 or the line into t1-2. This will obviously change once we go to a full exhaust which should see more power, longer uptop.
The biggest difference I found on the road was mid range torque. A car that could sometimes be a pain in the a** to drive in traffic with the torque dip etc is now awesome! Even with a torque dip still present the car feels so much more responsive and happy to shoot into a gap in traffic.
Now you’ll have to forgive me. This photo is stolen of the SME facebook page. I had some dramas on the night I fitted the header (stock header and overpipe were seized together, I had the wrong aftermarket overpipe etc) So i got the car done at 11pm the night before a Wakefield Park trackday so you’ll have to forgive my lack of photos.
If you’re shopping for headers you’ll find there’s a few options so i’ll give you a super short run down!
The biggest option here is Equal Length vs Unequal Length. The very short of it is Unequal Length (UEL) will alleviate the torque dip better by giving you more mid range torque but the sacrifice you make is top end power. UEL headers will give you that Distinctive “subie rumble”. Skip to 0:35 on the video below for an example.
Equal Length (EL) will sacrifice midrange torque for top end power and typically sound more raspy/tinny. Skip to 1:02 on the video below to see a great example.
For my application, EL is the way to go. On track you're very rarely in the rev range where you find the gains of UEL headers as you’re typically up the top of the rev range. Once I add a full exhaust so we can let the little FA20 breathe more uptop and a shorter final drive the EL design and philosophy will come to life!
Unfortunately we’re currently stuck in another lockdown so I haven’t had a chance to go back to the track yet. Whilst it sucks that we cant back on track for a little while it gives me a chance to catch up on some work thats been done to #project86 on these blogs. We’ve got some new parts fitted up to the car which i’ll be posting about shortly.