continued from above
Originally Posted by SoftBatch
To save some weight you may be able to get away with just the cats. When I had the '05 GT I had a muffler delete exhaust with stock headers and cats and was never above 93dB at the local autocross course. I know it's a different engine and exhaust configuration but there is also a big difference between 93 and 100 dB.
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Yea, I have heard a "muffler delete" exhaust on Kent's ESP-prepped S197. Its still pretty loud. With full length headers and a 7500 rpm redline on this Coyote motor, it might get a bit too loud. I don't want to be "that annoying guy with the loud car" at events.
Originally Posted by Leo_DOHC_GTS
We have been spinning our car past 7500 with a 8000 rpm limit. The car only picks up power beyond 7000 with a good CAI (we have a JLT) and just an off road H-pipe we see over 400 SAE on the cars we have tuned.
The shop car has; CAI - ported heads - long tube AR headers - X-pipe - resonator delete - flowmaster mufflers - 1 peice DS - RST clutch and flywheel. With SCT software we have gotten as much as 435 RWHP SAE.
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Ahh, some real power numbers from an S197 tuner. Thanks for replying. I noticed when we dyno'd the car it wasn't really losing power yet at 6800 rpm, so I could see it gaining a bit more up top with the right tweaks. I'm still planning on an eventual 7500 rpm redline. With the right tire choice (we've been looking at so many) in STX it could mean
a 73 mph 2nd gear speed. Virtually assured to never have to shift.
We cannot do the 1-piece driveshaft (the stock unit is a huge 2-piece unit that looks very heavy), ported heads, or the lightweight clutch/flywheel, but the rest is fair game. We need to look at the CAI offerings soon, as I'm getting tired of how quiet, stock and slow this car is already.
If anyone has experience with a Cold Air Intake on a 2011 GT, especially with before/after dyno numbers, please chime in. I saw a couple at SEMA already, but many weren't ready yet.
OK, onto the latest round of wheel testing.
The two Enkei test wheels arrived Friday but I didn't get a chance to test them on the GT until Sunday. The 18x9" ET45 FP01 fit fine. This wheel bolted right onto the front and rear, with ample clearance to the caliper and strut (front) and to the inner sheet metal (rear). Even without any camber and this 4x4 ride height the outer lip of the 18x9 wheel fit within the stock fender confines.
As they should - they are almost the same width/offset as the stock 19x9 ET42 wheel. In fact these Enkei 18x9's will be 3mm more inboard than stock, which is good - I like to run narrow track widths for autocross cars when I can, to make slaloms that much easier to navigate. Its worth a little time, as we've seen in testing where we time a car through a set gate length slalom, then again with wider cone offsets by just a few inches. You can see the big end link stud that interferes with some wheel/tire clearance when you push the wheel inboard. If it comes down to it we'll just cut/shorten this stud.
So the 18x10" ET38 Enkei RPF1 wasn't quite as easy to fit. The flatter spokes of the RPF1 didn't clear the caliper on the front, as we kind of expected, and some of you warned about.
Not a huge shock - so I tried it on the rear and it looked good. There's a good 1.5" more inboard room, too.
So back to the front with the RPF1 18x10". I didn't have any 5x4.5" wheel spacers, so I started stacking washers to get the proper clearance. Turned out about 7mm of spacer is all that's needed to clear the caliper with the spokes on the RPF1 up front. Then I counted turns on the lug nuts and had just a hair over 10 threads of engagement... which equates to 1/2" (which is 1 diameter). That's
just barely enough, and still only afforded about .040" of clearance at the caliper (but the
stock wheel only has about .050" clearance here). Hmm.
Then there was the outer fender clearance. With the already wide 18x10" and now a 7mm spacer. It looks... well, its damn hard to tell if it will clear at full droop and with no camber, even hard to show in pictures. With the stock ride height and stock camber, I'd guess no. But we're going to be lowering the car a LOT (2-3"), which will inherently add negative camber and tire clearance. And then with some more camber adjusted in at the plates, that's more outer wheel clearance we'd be adding.
So for now we'll punt on the 18x10" wheels, and retest this wheel again once we have the car lowered and a 285mm tire mounted to it (I've got plenty of dead Hoosiers in this size we can mount and test with). It looks like we'd need a spacer of some sort, which I can draw up and machine easily enough if it comes to it. So I'll get the longer wheel studs installed, just in case. We'll also get the remaining 3 wheels in the 18x9" set, then order the tires (I'll discuss the size and model in an upcoming post). I'll be buying all of the stuff mentioned in this post in the next 24-48 hours, so if you have suggestions/alternatives, speak up now.
Thanks,