Xnke

The chevette springs are getting harder to find, but they do work and result in about a 210lb/in spring rate. They do need to be cut down, as they are too long from the factory. The rears will need at least one full coil cut, 1.5 or 2 is possible on 225/50/15's...the fronts need at least two coils cut, and you will still have a 4" fender gap. Cut one coil at a time and drive it a week or so to see how you like the ride, before cutting them to the ride height you want.

If it was me, I'd add the baffles and swirl pot, and when I put it back together I'd stack the top and bottom halves, clamp the remaining lips together and TIG weld the edges, using MIG wire as filler where needed. Sometimes an autogenous weld isn't the cleanest kind of weld, and a little filler rod helps with that.

Yep. You can order whatever pad you want...but for street brakes, being able to walk in the parts store and get a set of pads (even the 4x4 brake pads are getting to be an overnight item now) that work is a good thing. Yes, the RX-7 pads have a little more pad area, the bottom corners aren't chopped off like the toyota pads. The RX-7 pads also are available in sports compounds, instead of 3000lb pickup truck compounds. (you can get semi-metallics for the truck, but you can get semi-metallic, ceramic, carbon-kevlar, etc. for the RX-7)

I think it's detonation plus torsional vibration of the crank...it's usually the #5 that goes OR the crank breakages that happen at the #6 main journal... Either way, I have a new planter sitting out in the shed!

The OEM bolts are not one-time-use, but they are the weak link in the stock bottom end. Go with ARP and don't look back.

Yep, It's 4 inches from the manifold mating face to the back of the intake valve, measured along the port centerline. I can say that, since it's a recommended length by four engine builders on three continents, plus many of the intake manifolds, including the Nissan Comp, Cannon, and the longer of the two mikuni-type carb intakes with performance velocity stacks, all of these intakes end up between 13 and 15 inches long, The Bob Sharp center-throttle design also ends up at this length, AND the somewhat-questionable formulas found on the internet and in the two textbooks I've got here predict good results with this length. The "local maxima" statement means that I believe you'll find a nice torque peak as well as a wide powerband on most well-prepped L28's when fitted with a manifold 15.5" long. It may not be the "peak" or absolute maxima of the curve, but I think it'll be a reasonably large peak, if it isn't the largest peak, if you graphed power output along the vertical axis and manifold runner length along the horizontal axis.

I've always used the he-man method, just because I have an easier time getting the splines lined up that way. The floor jack works good too.

This map won't even run in an MSnS unit. This map was defined for a Megasquirt-2 unit, firmware revision 2.867. Totally different software.

From looking at a LOT of photos of race intake designs, including Bob Sharp and Electramotive, and running some math a lot of times, it looks like a 15.5" long runner is a reasonable "local maxima" for torque production..which should happen about 5300RPM. Look at runner cross-sectional area next, and size appropriately. Again, drawing cues from photos, and even more time with the pencil, a runner Cross-Sectional-Area of 1.76" is also sized for 5300RPM. Hard for me to say what the area of the Bob Sharp and Electramotive cars was, as the runners are tapered. The runner opening as it entered the plenum on the BSR car was 65mm, though...tapering down to a 40mm intake port. The taper wasn't constant though, IIRC. If you're not moving the engine over, and you're not snaking the runners up over the valve cover, 15.5" or so is about as close to the shock tower as you'd want to get. You can go longer; but not by much! Remember to add 4" to the length of the manifold runners, to count for the port length inside the cylinder head. So if you have a 6" long intake manifold from cylinder head face to the end of the runner, then you are actually running a 10" long column of air. If you do roll the intake manifold over the valve cover, angle the ports up about 15* when they enter the head, basically match them up to the port floor. This will make for a U-turn of slightly less than 180*, and will give you even more room for your big turbo, as well as giving a little room to lift the port roof, straightening out the intake port more and *usually* yielding a little more flow. Not sure how well it would do with a big U-turn intake runner, though.

The Ford T3 is the SAME COMPRESSOR WHEEL IN THE SAME HOUSING. It's not any bigger. There was no upgrade there. The .48 A/R housing would do exactly what Tony said, bring in the boost sooner...but it would behave identically to the Nissan turbo with the same .48 A/R housing. Every functional turbocharger has wheels to measure...we're talking about the moving parts! If your Nissan turbo didn't have wheels to measure, it was a center housing, turbine housing and a compressor housing with no moving parts...

Looks like someone is going to be running 16lbs of boost and either a housing or a cam! U-joints BEWARE!

Yes, it would be better to get a cam cut...but the stock computer does not handle any cam bigger than stock! Make sure you are ready with engine management when you swap the cam.

Measure your wheel. You need to know the inducer and exducer sizes, for both the turbine and the compressor, in order to do this correctly. Yes, you can have the housing machined. Yes, it will still be a .63 A/R. What is "stage 3" about the other turbo? Is it a "stage 3" wheel, which not only varies by turbocharger vendor, but also by manufacturer...Many turbo shops sell the T-31 turbine wheel as the "stage 3" wheel, when it actually is just a turbine for a slightly larger turbocharger. As is the "stage 4" T-350 turbine, or the "stage 5" T-4 P-trim wheel, if we're going to go with AiResearch/Garret type numbers. So, we'll get specific here, with the assumption that you have a Garret TC4305. This'll help you and others understand exactly what I'm saying. The compressor assembly of this turbocharger is actually a T-04B H-trim unit, which is a pretty nice compressor for the L28. I'd keep this part intact. The turbine assembly of this turbocharger is actually a T-31, which uses the same inlet and outlet flanges as a T-3, but has a differently shaped turbine wheel for more flow. Less curl to the blades, but same inducer diameter as a T-3 unit and same shaft length and diameter. Exducer diameter is *larger* than the stock T-3, which means that a T-3 housing isn't likely to fit correctly, if at all. You will need the exducer enlarged in the stock housing. Getting back to measuring the wheel, if you are familiar with the math to determine trim of a compressor wheel, then you can figure the trim of the exhaust turbine as well. The T-31 "stage 3" wheel could be a 76 trim turbine, which is fitted in a variety of turbine housings from .48 to .82 A/R. It could also be a 69 trim wheel, which is more likely to fit into the stock housing. Before you go and have the stock housing machined to fit the T31 turbine, get a compressor map for the T-04B H-trim compressor and plot your airflow map. Make sure that you're going to get the most out of the compressor...which you can, if you run a max of 16lbs of boost, and you can bring it in at around 2900-3100RPM. Bring the boost in faster and you may run into compressor surge, it's been a while since I ran the numbers for this compressor on the L-28. This compressor series is actually much better for sub-2.0 pressure ratios than it is higher than 2.0. If you want more than 16lbs of boost, you need to go with a T-04E compressor. They will yield higher efficiency in that boost range, lower compressor outlet temperatures, and a much more drivable turbocharged engine. In short: Yes, you can do what you are considering. I would plot the compressor map FIRST, THEN I would think about running the smaller turbine housing. THEN I would look at my power band and see if it would be more beneficial to run the smaller turbine housing (which will bring the spool time down around 2300-2500RPM) and pulling from 2300 to 5500 RPM would work better for my application than spooling at 3000RPM and pulling to 7000RPM, by using a different camshaft profile, with modestly more lift and duration, but cut on a 110-112 lobe seperation angle...Personally, I know what route I'd go with...

The oil pump just drops off with four bolts. The sway bar is in the way. No need to unbolt anything but the passenger sway bar mount, and the four oil pump bolts. You will get oil all over you. The cleaning of hydraulic lifter assemblies is documented on this site pretty well. It's not difficult, but it does require some faith that when you put it together it'll work...and it won't always work.

You don't need to drop the pan to change the oil pump on any L-series engine. P90 Hydraulic lifters are prone to lifter slap when cold-started if they are worn or dirty...and most are just dirty. You can start the car, run it a few minutes until the noise stops, then turn it off and pull the valve cover. See if any of the HLA's are slack. They should hold oil in them for at least an hour, if they're dropping off right away then they are likely worn or dirty. What happens is that the lifter doesn't hold the rocker arm against the cam, and the cam lobe slaps against the rocker arm, which makes the noise you're hearing.

The evidence you seek can be found in "How To Modify"...

I'm very interested in what you're working with now...I've had poor luck with 7000RPM upshifts with my '71C box; but it does have 370+ thousand miles on it. Syncros still work for granny shifting but big delta-RPM's they don't handle well. Hopefully your experiments will reveal some tricks that'll help when I go to rebuild the 91 240SX transmission in my floor.

You just put the stock turbo right back on...with a water cooled center housing. Not a bad idea, the water cooling should help with oil temperature control, but as far as the compressor goes... There was no upgrade there. Yes, the compressor housing looks bigger on the outside...it is...but most all of the information I have on the stock Nissan T3 is that it's a 60 trim T3 compressor.

I knew the AN scheme; just a misthought...0.093 is 3/32".

Why bother with slotted OR dimpled? Are your brake compounds blowing off THAT much gas? Drilled, slotted, dimpled...they all sacrifice ultimate braking ability for looks/gas handling/cool factor. Modern brake compounds don't outgas nearly as much as some of the old ones did; that outgassing was the reason behind the drilled/slotted rotors. It's not for cooling, it's not for weight reduction...it was to give the gas from burning brake pads a place to go, instead of floating the pad. In short, why sacrifice both rotor integrity AND ultimate braking strength by removing rotor material?

It's pretty simple, you take an old toyota pad, and a new RX-7 pad, and look at the two. The pads are very similar. The difference is the RX-7 pad as a little more pad material at the bottom two corners, and that the two holes in the top left and top right corner are too high on the backing plate to put the pad material in the right spot. SOME pads have a squealer tab at the bottom center, just cut this off, it'll hit the rotor hub otherwise. Weld the two corners up solid; grind the backer plate flat again, and put the toyota pad and the RX-7 pad back to back. Align the top edge of the pad material, then clamp them together and drill the pin holes through, using the toyota pad as a template. Nothin' to it. I don't have a photo of drilling the holes, just the welded up and ground flat pad...forgot to take that photo. Those two center holes don't get moved...they are just to hold the anti-squeal clip and they fit fine.

-3 line being 0.093" ID, it's only a bit larger than the 0.060" restriction normally used. It may not be a problem; but if nothing else fixes the problem then you might look at that.

By spacer plate I mean cut out a copy of the water pump inlet flange about an inch thick, drill and tap it for the fitting, and sandwich it between the water pump inlet and the timing cover with two gaskets.

So I've been told these units are not rebuildable, that only PSE superchargers can do the job and even then not all that reliably. I have one that is literally dripping oil out of it, which is the failure mode these exhibit most often. They still make boost fine, the bearings are in good shape...but they blow oil vapor into the engine and the engine smokes badly. They are oiled via a pressure tap between the heads on the V6; and return oil via a gravity drain. I bought mine for 50$, I'll give it a shot. The bearings seem to be readily available...it's the seals that aren't. I think I can machine the housings for proper teflon lip seals instead of the carbon/graphite seals that are in place now. Once I figure out how to disassemble the dang thing! I managed to unbolt the rear case extension, front pulley, and the front case this evening. I'll need to borrow an impact wrench to remove the two 17mm bolts on the front of the shafts; they are ground similar to how a turbocharger turbine nut is ground to balance them. They will have to go back in the same place they came from, so I'll bag them. I have NO reference for torque; I'll have to make an estimate and hope it's correct. Once the front case was removed, I discovered that these units have a 4:1 step-up ratio from the input drive to the actual supercharger. That's cool, because it means that the input pulley is effectively 1" in diameter, but has the belt area of an 8-rib 4" pulley. Also, a smaller crank pulley is needed to produce the same boost as with some other superchargers, which is great since this pulley is unique to this unit and other sizes would be difficult to fit.

It'll work just fine as far as the divided flange portion goes. I'd have taken the grinder to the old T-3 flange and smoothed it off, and welded in a block off panel, myself. That would probably have warped it up some, though.