You need more turbo! Less tig, you been following Lazarus7 on golf.au? He just finished his 7163, but he hasn’t tuned it yet
Due to the lack of a twin scroll manifold for the B7, the TIG is needed for more turbo.
Talk to Derrek, he is making me one. Or are you set on welding your own now?
Someone weld me a Fast intentions catback with a JHM Y downpipe…for less than $1700. I want it…but if I buy this I will now have over $6k in different exhausts…I think that might be a bit silly.
I need to see how well I do with tig welding first. I would love to make my own. I also was thinking about modifying my B&B catback into a true dual system and making a new downpipe that goes to a Y like JHM sells now.
At the price you can sell your a4 cat back you could pick up an s4 cat back. I’ve seen used FI cat backs go for 6-700
I don’t know how easily I could sell my catback for though, since I sold the downpipe it came with a while ago. As it sits, it won’t bolt up to a factory exhaust, hence the reason I was just going to modify what I already have. I just need to remove the 1-into-2 resonator and run two 2.25" pipes up to a Y on the DP.
2.25 is too small for a bigger turbo
That’s what I keep reading, but I would have to change everything to go larger. Not in the cards at the moment, but maybe down the road.
In exhaust design, does turbo vs non turbo matter?
Lets say you want 400HP. 400HP takes X amount of fuel and Y amount of air. Whether its supplied by a turbo or by 4 more cylinders doesn’t matter right? so theoretically 3" is way overkill for a TBE. Like the k04 guys, they don’t really need 3" right? I mean hell I don’t need 3", RS4 is what like 2.75?
Am I missing something?
But what would matter is how quickly it expands to avoid back pressure in a turbo system right? So if you are coming off a single 3" you would want to quickly split into two 2.5’s and then back to whatever shenanigans you might have but 2.5" would be totally fine right?
Here’s the hangup I have with 2.25" being too small: It all comes off of a single 3" downpipe. You can’t really go much larger here due to space constraints. Dual 2.25" pipes have almost 1 square inch larger cross sectional area than a single 3" pipe. I’m having a hard time believing that it will be a bottleneck for the exhaust to keep the rear portion of my exhaust as is.
An NA car you need enough back pressure and a great scavenging effect for good power from an exhaust. Turbo cars don’t need back pressure because it’s done at the turbo. So anything after the turbo is a restiction. On a turbo car, the faster you get exhaust out the faster you can get more air in. So a high flowing exhaust system is needed, hence our JHM DP-Y and 2.5" s4 dual catback.
Using an old S4 cat back on the B7 A4 is genius - how much for a used one? $100?
that’s what mine cost. isn’t an s4 catback 2" ID though? seems too small.
No forget off the top of my head. It’s close to the 2.25 though. with a DP-Y it flows more than a k03 needs.
2.125
Does anyone have experience with the AEM Peak and Hold injector driver? It seems like an ideal solution to add 4 port injectors in addition to the 4 DI injectors. The only concern I have is whether the trigger signal for the DI injectors will be compatible with the controller. You can also use something like a boost switch to control when the additional injectors become active. Something along the lines of 4 small port injectors becoming live at around 15 psi boost and mimicing the ecu signal for the other injectors would be tits.
Depending on what unit you get I have never seen a unit that is activated by boost or any voltage signal.
Something to maybe do is just tap into the number 1 injector signal and run one injector of that. You can tone the pulse back on the aem adjustment box. Set it to 20% less duty
Yeah, after rereading the info, I was mistaken on that. I’m not even sure it can drive an additional set of injectors. It appears to be meant for people wanting to switch from hi-impedance to low-impedance injectors and not for someone looking to add additional injectors.
http://i10.photobucket.com/albums/a129/2fast4sanity/image_zpsadde268b.jpg
I started smelling clutch just as I was figuring out how to launch it. Track was closing 20 minutes after this run anyways, so I called it a night. Until next time…