403 LS2 FD - LS7 Build for 2020!

[Exidous]

If you read from the tailpipe it will usually come out a little on the lean side. Are you at 11.5 and N/A still? That's pretty rich.

You'll also get some wiggle if the rear braking is too strong. I use a 265 on a 10" and it's just right. No vagueness or wiggle on turn-in.

[MPbdy]

If you read from the tailpipe it will usually come out a little on the lean side. Are you at 11.5 and N/A still? That's pretty rich.

You'll also get some wiggle if the rear braking is too strong. I use a 265 on a 10" and it's just right. No vagueness or wiggle on turn-in.

I’m on stock brakes and stock prop valve still so it should be a bit front biased. The wiggle felt like it came from the front and not the ass end. There was some weird elevation change there right when I got on brakes might have pulled it a bit.

Yeah my wideband in hptuners is saying 11.5 and they told me it was 12.5 on the dyno with a tailpipe measurement.

[largeorangefont]

It’s the 275s on the 9.5 wheel. The tire moves laterally quite a bit with that setup... I think I have some on track pictures somewhere to verify.. it was alarming. 

I get way less tire rub now on the 10.5 wheels than I did on the 9.5 wheels with the same 275 tire. Effective offset is exactly the same between the 2 setups.

For what you are doing I don’t think it is a bad thing though. The car will ride and drive better when cruising, it will probably have more grip on exit and be a bit more forgiving. But it is just not going to be as crisp on turn in or under braking. You will feel that numbness waiting for the tire to take a set.

But check the alignment too just to make sure.

[Exidous]

I had that with 295's on the 18x10 in the back. The shift on turn in was unsettling enough that I went to a 265 in the back. I would have preferred to keep the 295 but CCW doesn't make my SP500 wheel the same anymore. Unless I had someone add 1" to the barrel and about 30mm in spacer.

[MPbdy]

For the RC1 I could put a 265 up front and keep the 275's as spares for the rear I guess if I really don't like it.  Other option would be a 255/275 stagger with NT01's.  I really like a square setup on this car though for rotating them and for handling balance overall.  It has always served me well.

I expected going from a taller 17" sidewall to a shorter sidewall of the 18" it would feel tighter up front.

The tough part is it is faster to change immediate direction like I expected, but less feedback in the wheel because I'm imagining it has a bit of squirm.  Not sure if that makes sense.  I am getting more used to it the more I drive it, but twice on that drive it started getting into the sketch area a bit when the car wanted to move around and the steering felt very floaty.  I need to get it in a little bit more of an open space to feel it out.

I'm hoping maybe I just have a bit of toe out in the front and correcting that will calm down the nervous feeling.

[kinger]

I'm on 17x10 square with 255/275 NT01 F/R and I love how sharp turn in is.  Those Front tires are stretched slightly to fit that rim and if I ever had an encounter with a curb the rim would get toasted but man it feels fantastic.  Its nice to get the car to a level where we are pinching pennies so to speak on what tires and sizes grip best.  LOF made a comment I probably added 100 hp to the rear wheels in traction and I would say that is probably true.  The car was not that great to drive until I got it on a proper tire.  Enjoy optimizing it!

[wickedrx7]

Love the video's, those roads look like fun.  I am pretty jealous... But it also helps to keep me from getting tickets...

How are the front tires for fitment?  Any rubbing?  What are you running for ride height to the fender arch?

I am 90% sure I going with 275-35-18 NT01's on my 10.5" wheels but i am mildly concerned they will rub....

[MPbdy]

Love the video's, those roads look like fun.  I am pretty jealous... But it also helps to keep me from getting tickets...

How are the front tires for fitment?  Any rubbing?  What are you running for ride height to the fender arch?

I am 90% sure I going with 275-35-18 NT01's on my 10.5" wheels but i am mildly concerned they will rub....

The canyons are fun!  They're actually a fairly well traveled highway which sucks.  There's nowhere to pass on the double yellow and there's usually a lot of traffic.  If you get lucky it is a fun ride but I don't feel good about blasting along at 100+ for long stretches like some others do.  The road is fast enough you could go 80 the whole way in a normal car and never slow down so it isn't really technical.

The front fits perfect it hasn't rubbed once.  My fenders are rolled flat.  My wheels are 9.5 +45.  Ride height FL/FR/RR is all 25 3/8".  LR is 25 1/16".  I did corner balance it once ages ago and it took some adjustment to get the cross weight dialed in.  If I remember right I set the car up at 25 1/4" everywhere and I definitely had to move them all around a bit.  I don't remember setting everything to 25 3/8, but again it has been probably 4-5 years since it was done. 

These ride heights are with 25.4" tall tires.  I was a lot lower with the 24.8" tall 17" setup.

Where do you run your ride height?  I can't go any lower.  My headers touch on speed bumps going at a complete crawl.

[wickedrx7]

The canyons are fun!  They're actually a fairly well traveled highway which sucks.  There's nowhere to pass on the double yellow and there's usually a lot of traffic.  If you get lucky it is a fun ride but I don't feel good about blasting along at 100+ for long stretches like some others do.  The road is fast enough you could go 80 the whole way in a normal car and never slow down so it isn't really technical.

The front fits perfect it hasn't rubbed once.  My fenders are rolled flat.  My wheels are 9.5 +45.  Ride height FL/FR/RR is all 25 3/8".  LR is 25 1/16".  I did corner balance it once ages ago and it took some adjustment to get the cross weight dialed in.  If I remember right I set the car up at 25 1/4" everywhere and I definitely had to move them all around a bit.  I don't remember setting everything to 25 3/8, but again it has been probably 4-5 years since it was done. 

These ride heights are with 25.4" tall tires.  I was a lot lower with the 24.8" tall 17" setup.

Where do you run your ride height?  I can't go any lower.  My headers touch on speed bumps going at a complete crawl.

I am on 285-30-18 Star Specs which are 24.8", my ride height is right at 25".  If I go with NT01's, they will jump to 25.55 with should theoretically put me around 25 3/8" on all corners.  My fenders are rolled and I don't get any rubbing currently.  I am pretty confident I won't have to raise the car up and and will be able to get a little more sidewall on the 275 tires.  I actually like the look a little better too....

[MPbdy]

Yeah it sounds like we’re right at the same spot!

I like the look of the taller tire too. With the 24.8-25” tall tires even though the car was lower it didn’t look low. People would tell me to drop it more...I would’ve had to be extremely low to get a similar look.

I don’t think you’ll have any problem at all.

[wickedrx7]

Yeah it sounds like we’re right at the same spot!

I like the look of the taller tire too. With the 24.8-25” tall tires even though the car was lower it didn’t look low. People would tell me to drop it more...I would’ve had to be extremely low to get a similar look.

I don’t think you’ll have any problem at all.

I actually had mine at 24 3/4" at one point and it would bottom out all over the place.  I was amazed at how raising it up a 1/4" helped. 

[MPbdy]

You'll love the NT01 over the star specs.  Have you ever had an R comp on the car?

[wickedrx7]

You'll love the NT01 over the star specs.  Have you ever had an R comp on the car?

I had ra1’s on stock rims way back in the day. Mainly used on track with minimal street driving.

[MPbdy]

So I checked my tire pressures and shame on me for not double checking after mounting them but America’s Tire set them to 25 on one side and 30 on the other. 32 front and 30 rear and the car feels a lot better regarding steering feel and sharpness. Set a little higher than usual up front to try and stiffen the tire up.

I put some time into the ls7 today. Not so great news started fitting bearings and the damn rear main is super out of round. Like .0003 in one way and .0032 on the diagonal. The block needs an align hone. All I can figure is the ARP studs are distorting the bores. Not sure how this was missed before, but it has to go back to the machine shop.

Ordered another set of $280 coated bearings, 1 under this time, and whatever the block machining is going to cost...I think the ls2 block was ~$400 to have done. Fun day lol.

I did get the rod bearings fit. Needed a full set of 1 tighter bearings which luckily my dad had in the drawer. The coated standards I bought for it are going in inventory I guess. Clearances fell at .0021 to .0025. Were well over .003” with standards.

The rotating assembly is off to the balancer. Gotta see if our usual shop does align honing.

[Exidous]

I'd imagine it was the ARP mains. It's the only reason I've kept the OE. Didn't want to have to hone the bores again. TSP actually did a really good job with the bearing clearances on my block so I can run STD everything. Why the fancy expensive bearings? I'm just running the regular mains that are about $80 and never had an issue.