alfaholics exhaust modification.

doing some modifications on the exhaust system of my track day car.

[@onboro_alfa_SGL]

Thank you for sharing your experimental results. Very interesting! Looking forward to watching the next 🍀 I’ve subscribed your channel 👍

[@nord.tuning]

Thanks.

[@gregculverwell]

I Would have thought that you need to get the correct A/F ratio accross the rev range before you draw any conclusions.

[@nord.tuning]

Yes this would have been better. I had some issues with the close loop system, and at the dyno I found out that my O2 sensor readings were off. So far from perfect, but I run a Alpha N injection system ( RPM / TPS based fuel calculations ) so the amount of fuel injected stays the same. Now when you make the engine more efficient it pulls in more air, the AFR will go leaner because the delivered amount of fuel is the same. When the AFR leans out and the power goes up you can be sure you made some progress. On this basis I made my conclusions.

[@AlfaElaborazioni]

great video! looking forward to see the evolution of this.

[@e.b.laefam5433]

Hi. Thanks for taking the time to make good videos. This one with a bit of a surprising result:) When are you going to follow up with an exhaust or headers with smaller diameter to see if that improves effect compared to the Alfaholics exhaust. I have an alfa 105 project so I'm curious. Also, what is the spec of the engine your using in that test. Cams? ported? Compression increased? etc. Keep up the good work!

[@nord.tuning]

Hi, I did this video when I was waiting on parts for my engine rebuild, unfortunately it will take a while before I can do a follow up. Probably next summer :( Engine specs: CB48 inlet CB47 exhaust. ported. alfaholic (big) valves ( the exhaust valve is actually smaller and flows the same as a modified stock valve) motronic pistons 10.8 : 1

[@nord.tuning]

Sorry the cams are two C&B ST1 these have the same specs as the CB48 cams.

[@kingduckford]

Interesting to see the loss of low end. Always interesting to see how port and polish isn't "free power" when you consider the effects across the entire power band.

[@kisajz]

Cool stuff, may i ask what's the specs of steel wheels (00:35 sec) and where they come from?

[@nord.tuning]

These are stock wheels for a Peugeot 3008 17"x 7.5j et29 8.65kg. I sought the biggest steel rims with 4x108 I could find on the Oponeo.nl website and modified the car to fit these wheels. So they won't fit a stock giulia, maybe they fit a wide body GTA. In hindsight I don't think these are the best track day wheels because they are to big and have to much inertia. A very nice wheel is the stock Citroen C5 wheel, these are made from pressed alu plate and look like steel wheels. 15"x6j et 18 4,8kg they fit a Giulia GT and maybe the spider not a stock Giulia sedan.

[@kisajz]

Impressive, never seen 17' on Giulias 😊 That Citroen 15's are exactly what i wanted to fit, ultra light wheel but i was worried about specs, et18 sounds a bit tight to fit on sedan

[@enkinibiru1231]

Hello Nord Tuning, I am really amazed to view your video. I have - as you - also tried to find ways to enhance an engine's performance through finnessing the exhaust system, including the expansion chamber. My work led to a series of calculations designed to be applied to any engine. My test engine was a stock 1991 Nissan Sunny 1,500cc daily driver. My intention was to let it "breath" better. So I changed the airfilter - to a better flowing one - and openned the restrictive airfilter case and completely rebuilt the exhaust system. My formulas are based on specific engine data that led me to fabricate a 4 to 1 header. Which had specfic - to my engine - inner width and length primary tubes, the Primary Tube’s Collector Outlet Size and finally the diameter, length and volume of the expansion chamber, after which I placed a muffler for it did not affect performance. I sold the car many years ago, but was so exited with the results. The driving characteristics were NIGHT & DAY As a matter of fact, the person who bought the car fell in love with the sound alone until he test drove it. Then he said "I cannot believe this is a simple, ordinary and "mundane" Nissan Sunny. So suttle yet powerful". He bought the car, no more questions asked. I never had the chance to really prove my formulas as thoroughly & scientificaly as you have. I later applied the formulas in other vehicles, whose owners were delighted with the astonishing results. So - Dear Nord Tuning - I would be thrilled to share my formulas (simple Excel spreadsheet) with you for a "test drive" I would love to know I contributed somehow to the automotive tunning world.

[@nord.tuning]

Hello, Thank you for your kind words. I use as guidance the formulas in the book: four-stroke performance tuning by Graham Bell. And the dimensions mentioned in the book: how to power tune alfa romeo twin-cam engines by Jim Kartalamakis. Nevertheless I would like to have a look at your calculations/excel sheet. Greetings Nord Tuning.

[@MechaNick03]

I would love to build an engine with you in the future, you really seem to me passionate about tuning nords

[@nord.tuning]

Thanks. But I'm very busy keeping my Alfa"s on the road.🤷‍♂️ Making these videos also consumes more time then I thought.

[@MechaNick03]

@@nord.tuning i mean with your channel of course, always interestedin different peoples opinion

[@fulcrum811]

Great videos. Love to see how you tune the AFR

[@Runesten28]

I wonder why @alfaholics did not grind down that lip if it means reduced power?

[@jimspackman8527]

Because the lip is only a step of you're looking at it backwards like he is in the video. When he shows his own version he's viewing it from the engine side. If you did that with "our" version you wouldn't see the lip and neither would the exhaust gases. We fit this exhaust system to the GTA-R builds so it flows well enough for 240 bhp. The loss of low end torque he ended up with is why we used shorter secondary pipes by the way. Jim from Alfaholics

[@davidklauer3422]

Good job

[@nord.tuning]

Thank you.