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One last RS4-only update for this thread and comparison.
Comparison to ISF: the ISF is much more of a "track car" and is far more raw. You feel the difference in weight, especially because the RS4's engine sits at the very front of the car. Both cars are very rewarding to go WOT. I think the ISF is more quickly gratifying because it's powerband is shorter as is its rev limit. Since my RS4 revs to 8500rpm, it takes "more effort" per se, to have fun, similar to an S2000. However, it is extremely gratifying hearing a Formula 1 derived high revving V8 wind up from 2000 to 8000 RPM. It's hard to say which is more enjoyable, so I suppose it depends on my mood of the day.
As a daily, I think the RS4 is very competent. The 6-speed Getrag manual is very easy and enjoyable to drive. The gear throws feel like a 997 S except less precise essentially. The suspension is more dailyable than the ISF (vs stock ISF and vs with coilovers).
I have launch control from a flash tune in the RS4 and off the line the RS4 seems faster. It's very easy to launch by gingerly slipping the clutch.
Additionally, I bought this car with 86k miles. I already had to perform more repairs within 3k miles with the RS4 than I had to with the ISF (which weren't a product of self-sabotage) over the span of 10 years
Changed a throttle body, DIY fixed nav/radio antenna, changed PCV hosing, changed vacuum piping, changed a coolant pipe (this cracked because I sneezed near it--so brittle). Audi parts are so expensive...and it is way harder to work on the RS4 than it has been for any Japanese car I've worked on.
Overall, both cars feel special to me. Some of the last N/A analog sports sedans.
I put on a 2.75" exhaust (x pipe and axleback), ram air intake, and had a flash tune uploaded (which made a huge difference in fun factor). Finished off with a detail. Done modding this thing! Will be keeping it strictly OEM from now.
Had to replace the GruppeM MAF tube with one from MRP with honeycomb air straightener. GruppeM MAF led to drivability issues and loss of power throughout the rev range.
I upgraded the front calipers to GSF/RCF calipers (using RR racing aluminum adapter) and RR Racing GSF/RCF 2 piece rotors. I'm loving the difference in stopping power. Here's the difference between the ISF and GSF calipers.
I also threw in the rear wilwood 4 pistons calipers for more balanced braking bias.
I used speedbleeders and brake bleeding was almost enjoyable. I also used Techstream to further bleed the system (Techstream engages and bleeds the ABS pump--you just have to undo one bleeder--though it cannot be a speedbleeder, which is fine since the rear wilwood calipers have multiple bleeders).
I also shipped my front LCAs to FIGs to get spherical bushings pressed into the front-most mount on the LCAs. Now I have all spherical bushings in the front suspension of the car, no rubber (polyurethane in the steering rack). I added an Ultra Racing chassis bar that connects the steering rack and front-most LCA mounting points together as well.
The steering and turn-in feels very Porsche-like now (I've driven a 997 Carrera S), still needs alignment. Love it! Next are some new tires, Falken RT660 (have tried ad08r, r888, mpsc2), so I'm looking forward to trying a new brand.
I recently did the same to my front end. Pressed in the front bushing (already had the solid rear bushing in place), put Figs upper control arms with solid bushings on, and replaced the very tired OEM suspension with Ohlins DFVs. I haven't replaced the steering rack bushings yet (I have them, just haven't got around to it, solving other header related issues first). I agree about the steering feel - a lot more sports car like. Very precise. You'll be surprised at how much better it gets when it's properly aligned. It still feels light on initial turn in, but give great feedback as you progress (I also have the 42 steering ECU).
I really love being able to put everything in place and torque it down without having to preload the bushings! Super bonus for poly/solid bushings.
The other important thing was getting the subframe centered and squared. Big help with performance and balance there. I have a thread on it, but need to get a video up.
I recently did the same to my front end. Pressed in the front bushing (already had the solid rear bushing in place), put Figs upper control arms with solid bushings on, and replaced the very tired OEM suspension with Ohlins DFVs. I haven't replaced the steering rack bushings yet (I have them, just haven't got around to it, solving other header related issues first). I agree about the steering feel - a lot more sports car like. Very precise. You'll be surprised at how much better it gets when it's properly aligned. It still feels light on initial turn in, but give great feedback as you progress (I also have the 42 steering ECU).
I really love being able to put everything in place and torque it down without having to preload the bushings! Super bonus for poly/solid bushings.
The other important thing was getting the subframe centered and squared. Big help with performance and balance there. I have a thread on it, but need to get a video up.
I saw your thread on subframe alignment. May be above my paygrade, but I definitely want to do that or have some shop do that. That thread should be sticky'd especially if you get a video going.
I also have the -42 steering ECU. This car is so good...
I'm running -1.6 and -0.04 degrees on both sides. Once I get the rear pieces, I'll push all four corners to -2.0 with the same -0.04 degrees toe out in the front and 0.12 degrees toe in at the back.
I'm running -1.6 and -0.04 degrees on both sides. Once I get the rear pieces, I'll push all four corners to -2.0 with the same -0.04 degrees toe out in the front and 0.12 degrees toe in at the back.
That's almost exactly like the specs I'm playing with. -2 F&R, rear toe 0.12, front toe 0. You think a pinch of toe out is worth it in the front versus zero?
FYI, I had -3 F, -2.5 R, liked that a lot but it seriously ate the front tires. -2F is OK on tires.
I like a little toe out to help the car turn. One thing to keep in mind, we get a huge amount of camber gain with the caster we typically run. If you're at the high end of the range for caster, you can run less camber and still get excellent performance. This helps a lot with braking because the tires are closer to straight when under braking (where there is normally camber gain just from suspension geometry).
I like a little toe out to help the car turn. One thing to keep in mind, we get a huge amount of camber gain with the caster we typically run. If you're at the high end of the range for caster, you can run less camber and still get excellent performance. This helps a lot with braking because the tires are closer to straight when under braking (where there is normally camber gain just from suspension geometry).
Good point with camber gain. I didn't see a huge difference going from -3 to -2 degrees (on the street), but I did get the RR Racing FUCAs in between, which give a + caster gain, which obviously changed the steering feel as well.
Got the Falken Azenis rt660 on. They seem to have stiff sidewalls. Excited to see how they work on the car.
I want to mention to anyone using the Techstream airbleeding procedure for brakes, which I believe is great. I have speed bleeders which makes the procedure not doable without pressing the brake pedal (which you are not to do in the cycling of the ABS pump). The procedure calls for cycling the ABS pump and bleeding it through the right front or rear caliper. So, my right rear caliper (RR wilwoods) doesn't have speedbleeders, while every other caliper does. The procedure worked like a charm and honestly the brakes feel better than they've ever had for the past 10 years (they've only been conventionally bled in my ownership, not with Techstream).
In other non-Lexus news, I traded in my s2000 for an evo 9 some months ago. Evo 9 is a special car--only made for one year, IMO the most desirable evo (although I do like the evo 6 as well).
Normally, I like to mod my cars myself but this Evo 9 was too good to pass up on--has a built engine by boostin performance with a precision 6466, all built drivetrain components, twin disk clutch (feels amazing), etc. It is so ridiculously fun (fast and precise) that I turn into a little kid driving it. The steering precision and feedback is unlike any other car I've driven. Blows the Audi out of the park with that in my opinion, but the ISF, with suspension mods, honestly holds a candle to the Evo in the steering/handling department. ISF is going to feel more numb naturally, but with the increased caster and all metal bushings in front and only some suspension mods in the back, it really is great! I think I constantly praise the ISF on here, naturally, but I cannot think of a better all-around car.
Love the updates JDMV8. I agrees the Evo 9 is definitely the best year. Very special car indeed. Would have been hard to get rid of the S2k though. Still an amazing stable of cars.
Originally Posted by lobuxracer
I recently did the same to my front end. Pressed in the front bushing (already had the solid rear bushing in place), put Figs upper control arms with solid bushings on, and replaced the very tired OEM suspension with Ohlins DFVs. I haven't replaced the steering rack bushings yet (I have them, just haven't got around to it, solving other header related issues first). I agree about the steering feel - a lot more sports car like. Very precise. You'll be surprised at how much better it gets when it's properly aligned. It still feels light on initial turn in, but give great feedback as you progress (I also have the 42 steering ECU).
I really love being able to put everything in place and torque it down without having to preload the bushings! Super bonus for poly/solid bushings.
The other important thing was getting the subframe centered and squared. Big help with performance and balance there. I have a thread on it, but need to get a video up.
Originally Posted by JDMV8
Some ISF updates:
I also shipped my front LCAs to FIGs to get spherical bushings pressed into the front-most mount on the LCAs. Now I have all spherical bushings in the front suspension of the car, no rubber (polyurethane in the steering rack). I added an Ultra Racing chassis bar that connects the steering rack and front-most LCA mounting points together as well.
The steering and turn-in feels very Porsche-like now (I've driven a 997 Carrera S), still needs alignment. Love it! Next are some new tires, Falken RT660 (have tried ad08r, r888, mpsc2), so I'm looking forward to trying a new brand.
I just finally did the poly bushings on the LCA How streetable are the spherical bushings as far as ride comfort goes? I am not worried about mirror vibrations but is anything jarring I guess? I am running 18/14 coilover setup already on the car. Just wondering if maybe I should ahve went that route instead.
Sharp edges are significantly more abrupt. I dialed back the shocks from 15 clicks to 17 clicks and it helped a lot with this, but it's still significantly more jarring than when I only had the rear solid bushing. I don't mind it until I get in the wife's GS F and remember how quiet my IS F used to be. Also, a whole lot of this depends on the roads you drive every day. If they're full of pavement breaks, you might really hate solid bushings. Where I live there's very little of that (relatively speaking), just like there's almost never road salt, so I have zero corrosion issues. After seeing the underside of your car, it looks like a typical rust belt vehicle. Not sure I'd want to go full solid where you live at all, especially if you're in the Philly (or Pittsburgh) area or drive there a lot.
Sharp edges are significantly more abrupt. I dialed back the shocks from 15 clicks to 17 clicks and it helped a lot with this, but it's still significantly more jarring than when I only had the rear solid bushing. I don't mind it until I get in the wife's GS F and remember how quiet my IS F used to be. Also, a whole lot of this depends on the roads you drive every day. If they're full of pavement breaks, you might really hate solid bushings. Where I live there's very little of that (relatively speaking), just like there's almost never road salt, so I have zero corrosion issues. After seeing the underside of your car, it looks like a typical rust belt vehicle. Not sure I'd want to go full solid where you live at all, especially if you're in the Philly (or Pittsburgh) area or drive there a lot.
Appreciate the feedback. Sounds like I will stick with what I have. Local roads have lots of cracks and haven't been paved in forever. They also still put brine down on the roads sometimes around here although I am typically pretty specific in what cars I am willing to subject to that when those conditions come. Thankfully I am in NC so not much further north than you. My buddy just had the car in Pittsburgh for 6.5 years until I bought it back off him. Slowly replacing every fastener on the underside of the car to make it history that that happened. The only major component that will need to be recoated is the diff from that.
07-23-23, 06:38 PM
