Racecar Rebuild: its been awhile!

[6G72gearhead]

I'll probably play with that over the winter, right now I don't have time to mess with it before the MiDiv event this weekend.

I'll hopefully be able to really set the car up over the winter and get it dialed in. I'm on a fresh build this year, so I'm testing things out.

[IVORY_G]

Subscribed, good to see you back and in full effect!

[6G72gearhead]

Its good to be back! I just got a set of Brembo Calipers in today, time to make sure I got all the parts for this winters build. Hope to have the car sorted out and ready for its debut at Nationals next year.

[6G72gearhead]

Anyone have any preferences for rotors to use with the Evo calipers? I've been looking at the DBA's from tirerack due to their interesting slot design, and it seem many have had good luck with them on the racetrack. I've also been looking at pads, but that is a different story, I'm up in the air between a set of Performance Frictions, and some Hawk track pads.

Well a little update, I didn't make it to MidDivs, the damned thing skipped 3 teeth on the timing belt after running for just a few minutes. The only thing I can think of is that the hydraulic tensioner is allowing enough vibration for the belt to skip. So I've ordered a new tensioner and I'll try it again, I'm a little worried as I don't want to mess these heads up since I don't want to mess with totally rebuilding this set again.

[xd_01]

man that sucks it always makes me nervous when it comes to issues with the timing belt.

[Galantman03]

lol same here. I'm dealing with timing issue right now.

[Blue3000GTguy]

Have you considered a solid tensioner?
When people start going big power on the 3/S platform, they get solid tensioners, because if we jump timing it's almost always DOOM.

[Silvertune]

Make sure when you tensioned it you pry the pulley into the belt from beneath it's axis of rotation. If you go over the top the clockwise rotation of the belt can actually pull the turn table up and as it snaps back down you get a bunch of slack that causes even new belts to jump.

I'd get the Performance Friction pads. Too many bad experiences with Hawk. Can't go wrong with the DBA rotors though.

[6G72gearhead]

The current update is the car is back up and running, just a little too late for any more racing this season. I guess its time to start tuning my new intake manifold design and developing a nice tune for the pcm. I'll be taking the car to my storage unit here pretty soon and getting it stripped for winter.

With the timing belt I ended up buying the tool and a new tensioner, the combination has worked wonderfully.

I'm debating leaving my Brembo's black or powdercoating them back to red. I'm thinking I'd like to start with totally fresh paint on them.

[8thLS6]

Nice you got the timing belt situation taken care of

[6G72gearhead]

Yeah, its not a fun issue since its bad news for the engine if something goes wrong.

I've been playing with ECUFlash a lot lately trying to figure out how to define my MUT tables so I can start logging in 2 bit load, anyone here tried to do anything like this?

Also I'm curious about using the big maps patch to get a finer control of the AFR's and Timing.

[6G72gearhead]

Since race season is like 5 weeks away I've ordered braided lines, rotors and pads for the Evo Caliper set up. Should be here next week, so it will be nice to have that done.

Looking at the SMF rules and my competition I'm going to have to do some major weight cutting to get down to a reasonable weight. I can flare front fenders 1.5" I belive and still be legal, really the simple solution would be to form a flared fender that replaces the factory one. If I'm going to really take this car to its potential I need a lot more tire. Like 295's or 315's. The minimum my car can weigh is 2125 lbs, I really don't believe this can be done while still in compliance with the rules but every bit will help. I've been looking into carbon panels, but no one actually gives the weight of anything, so its an exercise in futility. I guess its time to look into plugging off the sunroof, can't decide on thick Lexan or aluminum. Again, not sure if the rules will require steel.

I think I'm gonna try and make some lightweight aluminum intake runners to 1 drop weight, and 2 free up some airflow to make this thing breath. Along with a 90mm LS1 throttle it should have plenty of air in.

[Silvertune]

Even the heaviest 6g7 intake manifold weighs in at all of 11.5 pounds. And cammed 3.8's putting out 300whp run the 65 with zero choking issues. A 90mm tb will have the 3.0 at WOT at like 1/3 throttle. If you really want to be productive I'd put my efforts elsewhere.

[6G72gearhead]

The thing is I can get the throttle for cheap, and weld up a manifold for cheap, the biggest cost is getting the flange ends waterjet cut, which is cheap. The intake stuff will be primarily in preparation to hog out another set of heads and get some big cams. I guess if the 90 is too touchy I've got a 75mm stock throttle laying around somewhere. However watching the vacuum gauge on a dyno run on my 6G72 tells a little different story on how the throttle is flowing.

[Silvertune]

Who cares if its cheap when putting effort into other areas would yield more? I'd love to see a log of that vacuum gauge. If a cammed 3.8 isn't choking on a65 there no way in creation your 3.0 is choking even on a 60.

A 65 and a ported 3.8 manifold will outperform almost anything you could possibly DIY.

[6G72gearhead]

Not calling you a liar, but on a diagnostic gauge it never gets above 3"hg. Now, is this really choking it, no, but is there horsepower to be gained from reducing restriction, yes. Before you ask I have put the gauge to the crankcase vent port in the intake tube just to verify it wasn't filter/MAF causing it.

I know how good the 6G75 manifold set up is good, however the person I will be doing the manifold with has been building custom street bikes for years, and has designed and built a number of very well performing intake set ups for street bike engines. I know its not 100% the same, but much of the math and principals are.

More then power though, I need to drop weight, and that is a huge battle with my current budget. I graduate soon, so that should help, haha.

[xd_01]

What does your car weigh now and what have you removed so far?

[6G72gearhead]

I'm not sure, it should be under 3k lbs though. I need to weigh it at the school but the teachers don't really care for anything that isn't a lifted pickup or a muscle car.

So far:
Air Con, complete removal
Sound deadening
Trunk Carpets
Back seat
11.5 lbs battery on a custom lightweight tray
Lots of little bits and pieces like heat shields, EVAP parts, EGR etc.

I need seats and to remove the sunroof, those are big. I need to remove the sound system but driving it several hours to events makes it a nice feature.

[greddy]

I dont know how good the baffles are on the 6G series engines, but if you do serious tracking Id look into getting a baffled pan or having the OEM one baffled.

[6G72gearhead]

They have a few baffles in them, running 5 qts instead of 4.5 helps, I haven't run into any starvation at all in the 8 years I've been beating up these engines. Mine came apart very clean, almost new looking, it had spend at least 20k miles above 4k rpms at that point.

I'll probably need to baffle it at some point, but its not a major concern yet.