SleeperZ

You will lose power raising the compression - the extra compression will cause detonation at a lower boost level as you can't pull the heat out of the mixture inside the cylinder like you can with a higher boost level and an intercooler. in general i believe you are correct' date=' however if the goal is not very high boost, then the bumped compression would spool the turbos faster wouldnt it ?[/quote'] That may be correct. The power potential of the motor is less with increased compression, especially if you are restricted to pump fuel, but off-boost will certainly be exciting, and boost is always fun.

My 280 will lean out in hard left turns at 1/4 tank. Just fuel moving away from the pickup I suppose. A pump problem will be insensitive to acceleration, and the stock (turbo) pump is good for 250 hp or so. It sounds like you have a vent blocked in the tank - that's why it backs up on you.

You will lose power raising the compression - the extra compression will cause detonation at a lower boost level as you can't pull the heat out of the mixture inside the cylinder like you can with a higher boost level and an intercooler.

True, dat. It's not worth $100 though, it's plug and play. I picked up a spare distributor off eBay for $15. I sold it already, but keep your eyes open, they are not that expensive.

Unless you will do lots of autocrossing, stick with stock. The wheel is hard enough to turn.

The only electrical difference between the '81 and '82-'83 is the crank angle sensor. On the '81 it is mounted off the crank pulley, and incorporated into the distributor on all later models. The separate CAS is reputed to be unreliable. Otherwise, AFAIK, the motors and all else are the same.

The front diff mount can be torn, but appear OK when at rest. Have you checked the shock towers and the control arm bushings for looseness?

I consider myself somewhat of a cheapskate. I would use used sensors, because they do not fail often. New injectors are a good idea, though, but I also wouldn't bother with a new cold start injector.

A 50mm tb will not keep you out of the 12s - Shane ran one into the 11s. What seems to be keeping you out of the 12s is the same thing keeping me out of the 12s. TRACTION! Get your 60' time down to 1.9 - you already have the mph for a 12, and the Z is perfectly capable of consistant 1.9 second 60's.

Averaging 10mph over the 75mph limit in Colorado, I get 27 mpg. That Z31 ECU really knows how to close the loop for economy. I also have 205 width tires, lowered springs, and a front air dam.

Use anything you want. At those power levels, all of them work fine.

Bell Engineering sells turbo kits for 4.0 Jeeps.

I'm running 313 rwhp with 2" IC plumbing. That's at 15 psi boost. Shane ran my same IC and 2" plumbing all the way to a stock TB, getting high 11's on slicks.

Having a head builder do my P90 two years ago, including Schneider turbo cam, new springs and new rockers, complete valve job, head surfacing and minor machining around the exhaust valve, it set me back about $1500. It definitely opened up the top end, and, if my ECU would have let me, it wanted to spin past the fuel cut at 6400.

No, I think they will support a bit more. I ran very close to this with stock injectors last season. They were starting to lean out with a trap of 105, but the 260cc units supported nearly 250whp. I think these will get me close to 350whp without any trouble, especially since I'm running 45psi base pressure, 7-8 psi more than the stock regulator. Before pushing them that hard though, I will connect my handy-dandy Fluke Scopemeter - it makes direct duty cycle measurements.

You are probably right. Only way to know for sure is to measure the fuel pressure. How much base pressure were you running with the Aeromotive anyway?

They may not have shown respect before, but I bet they do now.

Bernard, the pic is posted in my HybridZ personal gallery. To insert it in the post, I just used the img links to link it in the post. If you can't see the picture, something else must be wrong. I can email it, but you should be able to see it. Let me know.

The air regulator will help with cold starts, keeping the idle speed up until it's warm. That's one of the few factory doo-dads I kept.

Here is the dyno graph. The scanner made it rediculously large. I resized it to 800x600, but it's hard to see the details... I don't know if they were measuring rpm correctly. Just because the hp and torque cross at 5250 doesn't make it right, does it? They had a single pickup on my coil wire, and entered the ignition event in the DynoJet software as occurring every 100*. That is wrong - the ignition event is 120*. Hmmm, the hp peak at 4500 rpm seems low, unless I just can't keep the torque up with that stock turbine...

The way I understand it is trap speed is an excellent indication of horsepower. I don't believe an N/A car will register a higher trap speed by simply going with a taller tire (or a lower gear ratio), with no other changes. Tthe way I look at it is there is no difference between going to a taller tire or lowering your rear end ratio. You end up with the exact same distance traveled per turn of the drive shaft, so it's the same "ratio". In my mind, that only leaves the increased load with the lower ratio increasing the torque of the motor (the turbo's role) as being responsible for the higher trap speed.

They are the same. Both are manifold referenced, about 37-38 psi.