We are full steam ahead getting ready for the car's second race at PIR this weekend!!
Two teammates, Blake and Tyler made the drive out to try and get the car prep across the finish line a couple weeks ago. We were quite productive.
Just to recap the car's history:
Race 1: Spun rod bearing due to lack of oil, original 250k+ engine, 6.5 hours into last Oct PIR race.
Rebuilt/swapped Xterra 3.3L engine over the winter
Track Day: Spun rod bearing again, low oil pressure
Bought Quest Van 3.3L engine from junkyard. 140k miles. Quest's have front-sump oil pans (only the s12 and the quest VG variants had this), and should be somewhat "drop in".
So, swapping the quest motor in was time consuming. Mostly because I had to kind of stumble my way through discovering all of the differences between the 3 engines. The biggest differences are that each engine's crank pulleys are unique, which means I have to use the accessories that correspond to the crank pulley. I wanted to use as much quest stuff as possible as to reduce the amount of work, but that didn't happen.
I swapped the S12 original cams into the 3.3L motor because the 3.3 cams are very small (for torque) and make peak power, 170@4800 RPM. That didn't sound ideal for road racing. The s12 cams make peak power with a 3.0L, 160 @ 5300 (if I recall correctly). One problem I found is some stress cracks near the dowel pins on the cams... great!!! We torqued the cam gears to spec, and decided to run them. The dowel does not hold the cam gear in place once it's torqued, so I don't think we'll have a problem. But I won't run these cams again probably... Instead I'll send the van cams out for regrinds and replace them over the winter.
About the time I had the cams swapped and the timing belt on, I started to realize I had a problem. The truck crank pulley won't work with the quest water pump, I don't have quest accessories, so I have to use it. Swapping over the quest water pump I'm praying that I can keep the quest oil pump (and not have to swap pickups, mod oil pan, etc!). So basically after putting all of the truck stuff on to the front of the quest engine, with the quest oil pump intact... Its looking like its going to work! Resealed the oil pan, front&rear mains, cam seals, valve covers, s12 manifolds on with new gaskets, motor mounts on, leaving dip stick on opposite side of engine because it appears to not create any problems... completely destroy the spacer in the back of the crank before it's removed so we can swap in a pilot bushing...and we're ready!
We also added an oil pressure gauge, and an oil pressure warning light to hopefully prevent another engine failure from running out of oil, or low pressure... I know I should have done this two engines ago.
The PS was another project. I was stuck using the truck PS pump that matched the crank pulley, but the bracket wouldn't fit at all (ran into the body). I ended up using the van engine bracket, making custom brackets to hold the PS pump, getting a 1" shorter belt, making new high and low pressure lines, and relocating the reservoir to the drivers side. JEEZ what a project! IMO the car is too hard to turn without PS, so this was necessary. Especially if the race is hot, driver fatigue is real over two hours!
We dropped the engine back in. Hooked everything up, and cranked that bad boy for about 45 seconds until the oil pressure gauge bumped up to about 12 psi. I installed the distributor and set the timing, which I apparently nailed the first try. Cranked the car over and it didn't even try to start.... connected the coil wire and tried again Fired right up, and sounded extremely smooth!
Blake also brought over his heavier duty mig welder, and Tyler dropped the diff/fluid and cleaned the crap out of it, and I welded that sucker up. This was a hotly debated subject over the winter. The car had bad body roll with the stock springs, and bad inside wheel spin in all the tight corners...the throttle was useless in the chicane turns 1-2 and in turn 7. Over the winter I found some higher spring rate rear z31 springs and cut them to the correct height. I ran them on the track day that killed the engine and found the inside wheel spin had gotten worse. Now the inside rear spins in medium speed corners as well (turns 4, 5, 6, and 12). Something had to be done, but a diff that goes in this car is going to be $1000+, which we can't do right now. I ask the Lucky Dog group how people feel about racing with welded diffs. The consensus is:
Your car has a balance problem that's making the inside wheel spin miserable
Welded diffs are great for racing! (from literally every person who'd raced with one)
They had a point(s). 90% of the weight I'd removed from the car had been out of the middle/back of the car, and I still have a big iron V6 with a fully intact turbo hood scoop (that I don't have the heart to cut) and pop up headlights. They suggested: loosen the end of the car with drive wheels and/or tighten up the opposite end. So: stiffer front springs/bar or softer rear springs/disconnect sway bar, balance corner weights better. Since the race is very close and I don't have the ability to play with spring rates/aftermarket front sway bar etc., I did a few things:
I had a mk1 hood from a parts car (mk1 hoods do not clear VG's without cutting). We cut half the bracing out of the bottom and added louvers carefully with an angle grinder. The hood is 14 lbs lighter, and should help with cooling and reducing some lift. I also removed the headlights and motors (there will not be any racing in the dark this weekend) that dropped another 9 lbs. So roughly 25 lbs dropped from the front of the car. Then we removed the rear sway bar. For good measure, we welded that diff. We may have caused some other handling issues, but I'm pretty dang sure we've at least solved the inside wheel spin!!!
This week I ducted the radiator/filled in gaps so that air could not flow around the radiator. This turned out to be the best mod yet, because it's looking like the race weekend will be 104-106 DEGREES!!!!!!!!!!! Regretting not building a coolshirt system, upgrading radiator, adding oil cooler, etc.
Wife made decals!!
I have been wanting to spend $140 on an IO Port seat back brace for a while because I feel guilty not having one for some reason... It seems like it would make the seat quite a bit more stable in a crash, and I thought it would be a good safety mod. Well.. the want was strong, but it couldn't grow my bank account, so I duplicated it with parts from Lowe's Racing Supply for $14. I'm very happy with it for only 10% of the cost of the real thing.
So there's a novel of an update for yah. Racing this weekend. Can't not be freaked out worrying about the car and the temps, etc... But also very very excited. I can't wait. Update soon!