illwillem

Headliner is out so I can rewire stuff when I do the carbon roof. TC-4 are not heavy but not the lightest wheel i can get. You can get the pro forged version and they are light.

Jwconeil

What brand roof are you going with? I’m having a hard time finding anything outside of Novel.

illwillem

I'm having the roof made by ALPHEYGA. They already make a buncha of other cool carbon ISF parts, the roof is just another they're adding to their line up. If you in the market you should hit em up.

Jwconeil

Please post a review of their roof and the process of installation, including needed supports. This is on my serious buy list, along with Tillet carbon seats and Ohlins coils. I’m undecided on aero, because I don’t really know what i need yet. I hope to drop down to 3350 pounds while keeping interior.

illwillem

Will do


I think that your goal may be a bit tuff with full interior. So far I brought my car down to 3429lb with a 100% full tank of fuel (car has not been corner weighted yet). It currently has no air bags, Titanium exhaust, no oem seats front or back, a single recaro race seat, no rear bumper beam, a carbon hood and rear door window motors and some other stuff. . I've retained AC/heat, center infotainment (heavy), condenser compressor and the majority of speakers. Yet to put the carbon roof on or finish gutting the rear doors; so there is still so weight thats coming off. I will be adding the roll bar, harnesses, passenger recaro, rear wing and chassis mounted splitter. I'm pretty sure with the removal of the final weight but the addition of the roll bar and aero ill end up around the same place. The last few places of low hanging fruit would be the 2 piece rotors and a drive shaft. Both of which i'm reluctant to get for one reason or another.




It is looking mean though.




Next phase of stuff starting to get finished, its shaping up to be even more rad.






Also, Figs jack jaws can survive a 100mph tumble off the bottom of the car. Who knew.

Jwconeil

The roof is 125 pounds or so from other stats that I read. It’s very significant. The carbon drive shaft does not lose any weight from what i have seen. The rotors do, but they cost significantly more than OEM on eBay. Personally, I decided to stay oem brakes for that reason. The 2k I saved on brakes can go to other important pieces.

I have never seen that splitter. Who made it? I believe the only functional splitter produced for the ISF is the Alphyga GT4, with the exception of your custom splitter. Looks much more effective at producing downforce. It also looks like you better be careful parking .

ljdsong

iTrader: (1)

So with your set up , did your isf" light up the fire" compared to your CTR? Correct me if im wrong, i think you missed, the magic ,most dramatic improvement in your isf, in terms of handling.
Leo

illwillem

From looking at the mechanisms involved in the sunroof assembly and the structure itself- its all aluminum and rather compact. The glass is going to be the heaviest part but even that is not substantially big, i'm really doubting the info that's out there regarding its weight. 125lbs is A LOT and i just don't see the mass to make those numbers. It would be great if it was, but again, i don't think so. Eitherway well know soon enough, ill weigh it and post back here with some definitive numbers. Surprising the carbon shaft doesn't save, typically on my pasr cars its at least good for 10-12 lbs. I am of the same mind as you are about the 2 piece rotors. They definitely have in both weight and transitional behavior advantage but when you track as much as i do the cost benefit of $500 replacement rings starts to loom large. I may get a set to swap on before competition events and just run the blanks otherwise. Well see.

Splitter is custom, and like the bumper has a quick release chassis mount capability the idea is I can add it easily once I get to the track.


LJDsong- Yeah your right. I've gone faster (so far) in the CTR but i always just have an 'Eh' feeling after lapping in it. Its a great car for beginner/intermediate drivers as it has a very safe and controllable disposition on track. The ISF, when set up, has some more sharp edges and requires a but more involvement. I haven't done many events in the car since i'm still busy building it but the ones that i have done get more and more fun to throwing such a big chassis around.

ljdsong

iTrader: (1)

LJDsong- Yeah your right. I've gone faster (so far) in the CTR but i always just have an 'Eh' feeling after lapping in it. Its a great car for beginner/intermediate drivers as it has a very safe and controllable disposition on track. The ISF, when set up, has some more sharp edges and requires a but more involvement. I haven't done many events in the car since i'm still busy building it but the ones that i have done get more and more fun to throwing such a big chassis around.

your right! the CTR is point and shoot . It eats up a lot of V8s in the track.
what im refering as the magic was, are you not putting a osgiken in your F. Its tranform the car like point and shoot.
leo

Jwconeil

Now it does surprise me that a stock CTR will outrun a stripped ISF. I don’t remember your power mods, and I think you have an open dif. Maybe those changes will Make the difference.

Jwconeil

You sure the roof is aluminum? Will a magnet stick to it? I could have swore it was steel. Maybe I just made that up.

if that’s the case, a carbon sunroof delete kit would be a nice alternative.

illwillem

Yeah im sure, the inner track structure for the sunroof is aluminum. Not the roof, the roof is steel. The aluminum framing for the sunroof tracks are bolted above the doors where the roof skin is bonded to. To me, the glass and those tracks will represent the heaviest parts of the roof when talking about the carbon replacement savings. The OEM roof skin is steel but relatively thin, apparently thin enough the Lexus saw fit to engineer some cross structures in a few places side to side to help give it some rigidity. Most cars; Civics, BMW M cars and Nissans that i've taken apart do not have this.

When you say 'out run' it makes a difference if were talking about track driving or drag racing. If drag racing i think the ISF may have it. On a racetrack you have a lot of other things working for my CTR and against my ISF as it sits at the moment. Lift at speed, bigger tire size relative to weight, where it makes its power etc.. Like you said traction is definitely one of them(at least while i wait on my OSG TDC LSD to show up.) Once the car has the proper aero package and roll stiffness with the new suspension it will no doubt be faster than a stock CTR. But looking at it like that, stock for stock, the CTR absolutely KILLS this ISF on track in just about every way. I do think the outright tuning potential of the ISF is at least as high as the CTR, dollar for dollar. On the CTR you just start from a much better baseline.

For reference I turned off all aids with the pedal dance on my first session of this last track day. I got on track and no matter what i did i couldn't put any power down on corner exit. Next session i did the push and hold 10 second which disables the VSC but leaves on slip management. In a hotter part of the day with that much more abused tires i was a full 4 seconds faster when leaning on the electronics to sort out the wheel spin. I probably blitzed my rear pads but it was faster. Its NOT ideal but if you're going to track an 08-10 ISF its 110% the only way id recommend doing it.

ljdsong

iTrader: (1)

Jwconeil .You have to drive the CTR to the track. Its point and shoot. See this pics youll be surprised more

Before

After

myclue

love what you did to the car!

Leander311

iTrader: (2)

Phenomenal work/project... especially considering the $125 buy-in!

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