RebekahsZ

Looks good. Now install it and tell us how it works. I've thought about cutting mine but was afraid the cutting might hurt the heat treatment. One way to find out!

Does MiKelly's car look ridiculous? I sure don't think so. It's awesome. The tire diameter is not really any bigger because the sidewall is shorter.

Availability for 16" tires isn't very good. 17" tires are super common. 18" tires are all the rage.

Lets all be a little more courteous and thick skinned, please-we are all friends here. I've learned a lot from this thread, so lets keep it going. For example, I hope to add two oiling mods this winter. 1) an Improved Racing baffle set. 2) a low oil pressure warning light. I also plan to add a puke can to the engine oil venting system. But what I don't understand is this: why should I put a vacuum source on the puke can (vs) simply venting it to atmisphere? I'm in no hurry to modify the PCV system because I can tolerate an occasional puff of smoke, if that's the only negative to the stock system(?)

Have you considered 17" or even 18"?

-glide? stall? tire?

That was my plan, good friend! I was next in line to go with the 2-step pushed up to 4500 (the level that has cost me the two driveshaft yokes and an inner CV at this sticky track) when the car ahead of me deposited his transmission case and all of its oil at the staging lights. The plan was to turn it up 500 rpm per run till it either didn't bog or broke. Unfortunately the day got cut short, but I was game to leave it all at the track. Hell, I'd have all winter to get it back together! But at least I can daily it now till my truck is out of Purgatory. I was at Subway today and coming back out and strapping into the Z, I got the biggest grin knowing that I was eating a sub while driving back to work in a car that can hoist the front wheels. All thanks to hybridz!

Paint the floors with several coats of good automotive paint.

Koni 8610-1437RACE single adjustable on sectioned stock tubes. 250# rear spring, 225# front.

You are right, but ls1tech guys aren't any smarter than we are. Professional is a worthless word. I dropped my truck off to a professional with a great racing pedigree in July for an LS swap and after $13,000 and 3 sets of main bearings, I'm still driving the Z that I built myself while the truck gets un-F'd. .

16s should be fine. 15s is a gamble. Cast aluminum 15s usually clear by a gnat's ass, but spun aluminum or steel wheels are a no-go at 15". If you only clear by a gnat's ass and you do a number on your wheel with a pothole, you might get a chance to repair more than the wheel.

heavy85 (I appreciate your opinion)-so you are draining from your puke cans (which have vacuum on them from the throttle body), not from your intake manifold-am I getting that right? I'm not sure what you mean by pushing it...I'm hauling ass best I can. I don't know how I measure up on Gs, rpms and what not, but I yanked both my tires off the ground 3 times at the dragstrip on Saturday. You'd have to ask CobraMatt how I'm doing on lateral Gs, I really don't have a good reference due to inexperience. I wonder effect the location of the vacuum port on the intake stream has...the LS1 port is on the throttle body, whereas my GTO intake system has it on the plastic snorkel tubing further upstream of the throttle body. You've got your puke cans on vacuum; I think SunnyZ has them to atmosphere...

My ultimate plan is to build a drag-only Z, 275 drag radial car and put a solid axle and a powerglide in it (funny car style cage, wheelie bars, a trailer hitch and a parachute will be part of the initial build). I think for this car I'm gonna keep it simple and just drop back to the 26" slicks and raise my rev-limiter to allow me to finish the race without a shift. I really only went to 28s to try to get the last few feet of the 1/8-mile done in 3rd gear. Remember, this is my daily driver, my standing-mile car, my autocross car and my road course car-I can't go all the way for drag racing. I'm walking on the wild side every time I go to the strip and I can't believe I made it home with trailer optional after dead-hooking 5 times in a row and getting light in the front 3 times. Weedburner-you are totally right. I've read your stuff and it is super cool, but I don't want a slippy clutch, but I did pay attention to your advice on tires and shocks. A couple questions: If I raise my air pressure, will the bias ply slicks be less shock-absorbant (less sidewall wrap?)? I was thinking that maybe by dropping tire pressure I was reducing the tire diameter at launch so that it would behave more like a shorter slick. When you say "less rear shock", do you mean less compression resistance or less rebound resistance? I had the rear shock on full stiff for rebound and the front shock on full soft for rebound. Compression is non-adjustable. I run 250# rear springs and 225# fronts.

How do you know you are getting a cup of oil into the intake? Do you pull it after each race and pour it out? I've just been driving the hell out my car for two years...that's why I don't understand this problem. I'm checking my oil level and its doing fine.

Yes ZG flares. Having trouble getting the video to download because it is in .mov format. And it is turned 90-degrees. The car had the traction to hoist em up, but not enough power to tote em more than about a foot or so. The video looks kind of ridiculous-like I hit a speed bump too hard. Thank goodness I kept my 26" slicks. I think the 28s will have a place on low-traction tracks, but I will definitely be going back to 26s and need to get hp-tuners to bump up my rev-limiter. Everything you said about 60-foot times is true to my experience. It was a good cool low humidity night-the car should have been faster.

Ok, cool. Practically, how do you put a vacuum on the puke can, other than pulling the vacuum from the intake side of the engine? Belt driven vacuum pump?

I'm not sure if everybody here is talking from LS experience anymore or perhaps just in theory. A couple questions: 1) if pulling crankcase fumes into the intake stream is all that bad, why does GM tolerate it on all their cars? 2) Can I expect some measurable performance gain from capping the PCV port on the throttle body and venting directly from the valve cover to a puke can? 3) somebody was suggesting a vacuum line to the puke can?? 4) by what pathway does the intake fill with oil? What part of the intake fills with oil?

Huh?

4000rpm 2-step clutch dump, 3.54 R200 CLSD with 28X9X15 ET Drag slicks 17psi, stock LS2 400hp/435tq, Z31 axles, Chequered Flag stub axles, single-adjustable Konis with rear rebound set full stiff and fronts set full soft. Mantic ER2 clutch and pressure plate. Lots of VHT with beautiful track prep. Both wheels up during dead-hook, but engine bogged and dropped the wheels back down, almost instantly. Two more wheelies during the night, but this was by far the best. Lowered tire pressure to 15psi and reset 2-step to 4500 with plans to keep increasing 2-step till either I got some tire spin or broke something, but the car ahead of me in staging blew his tranny up and dumped all of its oil all over the track and drove right down the groove to half-track before grinding to a halt in the middle of the lane. I saw 2-hours of track cleanup coming, so I loaded up and headed home. Car performed below par with 1.60 60' times and consistent 7.30s at 96mph, mostly slowed by dead hooking, even bogging the car on gear changes. I may be going back to 26s for this track since they put so much VHT down.

Popped my first little wheelie at the track yesterday! Mantic ER2 clutch, 3.54 gear, MT ETDrag 28x9 at 17psi, 4000 rpm on the 2-step. Having trouble posting pic and video taken on my buddy's phone. Looks awesome in the pic, but from the video, it just looks like I hit a little speed bump! Kinda like a little frog hop. But it was both front tires for sure! Had two other smaller wheelies on the five passes we made. Was in line with the 2-step turned up to 4500 and 15psi in the tires when the car in front of my left big pieces of engine and oil all over the track. It was gonna be a BIG clean up, so we got out of line and came on home. Car was not as fast on the 28s as on 26s. Not only was it dead-hooking off the line, it was bogging a bit on shifts. Either I'm down on power, or 3.54s and 28s plus tons of VHT on a perfectly prepped track is just too much for my modest 400hp. We walked the track before racing started-the surface was amazing.

If "filling up" the wheel well, look into tire DIAMETER. The smaller wheel will require a taller sidewall. And yes, you are crazy-everybody on this site is.

Every car is different, but yes, they should clear. Look at lots of pictures-most guys put this flares low to get the hellaflush look, but those of us racing mount them high and do a maximum cut of sheetmetal. It's pretty scary if cutting good metal.

I recommend that you do it with wheel offset. Any other way takes a huge commitment. If you do it with wheels and you later decide you don't like it , it is easy to change. I have changed my mind a lot over the 25 years Ive owned my Z. To do what JMortensen is doing is a commitment that few could follow thru on. And check my recent thread on how wide wheels really make a car a handful to drive. By just changing wheels, I can put skinnies on during the week and drink coffee when I drive, but no way can I do that with my track tires on.

Tires, alignment, brake pads and rotors all swapped to be ready go to strip tomorrow for last blast of the season. Now the lower hinge mounting for the drivers door is acting like the metal is fatigued and cracking. I'll try to have it patched up this winter, but it looks like I'm about two winters from a paint job (dreading that). This old body is so hammered and tired!

I don't think it hurts anything and its a little outside the scope of this thread, but I get a little blue smoke from my tail pipe when engine braking. I think it is because I am not vented to atmosphere but rather the stock GTO PCV crankcase venting into the intake stream before the throttle body. I think the high vacuum on decel is what really sucks on the PCV system. Puke can is on the list to try to keep my car from looking like it is worn out.