Shaun41178(2) wrote:I would say there are no major issues right now. There are a couple of minor things, but with this being a custom setup, certain things I have to live with, and since its a weekend warrior, the minor issues are very easy to live with.
1. Idle. When first fired up, the idle is good right around 900-1k. as the car warms up, the idle climbs to around 1300. Seeing as how this is a racecar intake, I live with it. It loses that lope as the rpms come up, but thats no big deal. I think the issue is in the tune. I think its a correlation between coolant temps, and the iac valve. As coolant temps rise, so does the idle. I will have to check with Ryan about that and see if it is correctable.
2.Tuning is just as easy on this ITb intake as it was on my single throttle iron head engine. My afrs are easy to dial in, and timing is easy too. I have talked with Ryan about more timing since I am running e85. Timing on 10 lbs is only like 13 degrees which is holding me back power wise. I have sent him some new timing maps to make, just haven't pulled the trigger yet. Its already making a ton of power on only 13 degrees and 10 lbs as is and I am sure the stock parts aren't liking it.
3.It does take a bit to learn to drive it. Much less throttle input on the right foot is needed to get going and to accelerate from say 50-60. Its just light touches unless you want to lay into it.
Synopsis; I am very happy overall with how it has turned out. throttle response is great, and with the ported heads, large plenum,lightweight flywheel, and top end cam, this thing climbs hard passed 5k rpm whereas my old iron head was meh comparatively speaking. The power it is making is unbelievable for the boost its running. I totally underestimated just how much power it was going to make, and how fast the car was going to be, when I was building this setup. Its faster than a new stock mustang gt, and new camaro SS, in line with a new Stang gt350r and not far off from a new z06. A tad more boost would put me with a new STOCK z06. With the higher compression, E85, and turbo efficiency, its a strong runner that has really impressed me
Ill prob look to drive it a small amount this summer, and more in the fall when its cooler as I have no a/c in it. Then if the setup hasn't blown up yet, as I plan to keep increasing the boost, I'll junk the shortblock and part out the top end and install my 3900 lz9 project I have on the engine stand.
It's really awesome to hear that it's all coming together and synergizing... and that it's really fast. Get some dyno curves.
1. Have you blocked off the IAC and tried starting it? Is the air that lets it idle at 900 RPM a leak, base airflow with closed IAC or the IAC's home postiion? If your base airflow with the IAC fully closed gives you 900 RPM, then you will not be able to control the idle any lower than about 1300, as the IAC won't be able to close much further than that. You want your base idle airflow with a closed IAC to result in more like a 400 RPM idle... that way when it's passing enough air to bring the idle up to 800-900 RPM, the IAC is in the 35-40 step range, which is the sweet spot for having control authority to either speed up or slow down the engine.
2. It's great that it's easy to tune. ITB's can be finnicky with the MAP signal on MAP systems, but generally require almost no accel enrichment or decel enleanment, so they're very easy to tune in that regard. Once you have a plumbing setup that gives you a solid MAP signal, you're golden.
3. The six throttles working together give you *WAY* more throttle area for air to get into the engine at *WAY* lower pedal angles than a single or dual throttle would. You can compensate for this with a progressive throttle cam that opens the throttles very slowly in the first half of pedal travel and then more quickly in the second half.
Why would you part it out? Think your plenum won't take that much boost? Or just that the intake doesn't fit the Gen IV (Gen V?) heads?