TimZ

It does seem that people are having more problems with the FelPros, but there were a couple of pretty major guidelines that were not followed here. Namely, not heat cycling the engine and retorquing the head (I generally do this three to four times just to be safe), and then running an unknown calibration at WOT on this fresh, never-been-retorqued gasket. Both bad practices, either of which could easily have been the cause of the problem. I'd look at it this way - yes, replacing the head gasket is a pain, but nowhere near the pain or expense of the broken ring lands that you very likely would have ended up with had the gasket held. Granted, I don't use FelPro head gaskets myself, but I've often wondered how much of their bad rep is simply from the fact that they are FAR more widely available. I'm really not trying to sound harsh here, and I'm sorry you are having problems, but these are pretty important points to understand, and they aren't necessarily obvious.

Hopefully it's starting to sink in from several other posts' date=' but there is no such thing, unless it's been proven good on [b']your motor[/b]. This is especially true for speed-density systems, as is used on most aftermarket EFIs (including MSnS). Even if the CRs were the same, "pretty much the same" is nowhere near being good enough to just plug and play. There are so many subtleties that can have a significant effect on your AFR (the voltage issue you mentioned is just one of them) that you should only use someone else's tune to get your motor running and then tune it yourself from there. Sorry you had to learn this the hard way. Also, checking timing with a timing light will only verify that the timing matches the timing marks on the crank pulley. It will not verify that the crank pulley is correct.

Two years later - I guess it's time for an update... Upgrading broken driveline bits has really put a damper on testing the spoolie jobbie. I was having some problems getting the actuator to work reliably, so I did a couple of initial tests, just to get an idea of the potential of the setup - I went out and datalogged two WOT runs, the first with the spoolie throttle open, the second with it closed. Initally, when I tested this with my old Isky L475 grind cam, the spoolie jobbie appeared to cause the turbo to spool about 700rpm sooner, which I was pretty encouraged by. To be honest though, I wasn't that unhappy with the way the turbo spooled without it, so my development time was first spent just getting everything running with the spoolie throttle open. Then my trans broke. Upgraded to a GForce T5. (took a long time). Switched to a more radical cam from Elgin. Then my r200 broke. Upgraded to an r230 (took a long time). So early this summer, I decided to revisit the spoolie jobbie, as things were starting to settle back out. Interestingly, when I performed the same quick test, closing the spoolie throttle now caused the turbo to spool later, and even limited the max boost that was being built. Seems the new cam really hated the increased backpressure (my turbine housing was a T4, o-trim, .84AR - closing the throttle dropped it to a .42AR). Since then, I've kind of given up on it, and have just been running with it out of the loop. I still think the idea has merit, but it looks like it probably won't make up for lost bottom end from a radical cam. I think you'll either want to use a cam that is pretty robust to backpressure, and/or go to a really large AR turbine housing, so that you don't have so much backpressure when the spoolie throttle is closed. As I see it the issues with these two approaches are that with the former (milder cam), you'll probably get a bit better boost response, but the cam will still pretty much limit the max power that you are going to make. With the latter (bigger AR), you won't improve the boost response that much, but you might be able to take advantage of the reduced backpressure with the throttle open.

Okay, now I'm afraid we really have hijacked this thread - I'll post an update in the thread that was linked above. Sorry about that.

Hmmm - looks familiar...

Sorry to keep going "off topic" but I don't think this is right - the exhaust valve opens well before bottom dead center, so there should be no appreciable difference in the exhaust velocity on the exhaust stroke on the higher cr motor, unless the cam profile is radically different. Yes, it did turn into a bit of a debate, but the debate still centered around what is effective and what is not regarding changing the turbo spool, and what trade-offs you might be making to acheive the change. This knowlege is key to understanding how to tune for the effect you were looking for. The most reasonable advice that I saw was to tune for maximum power in the boost transition region, rather than trying to change where the turbo spools. This way you will get through the transition region sooner, and it will feel like less lag.

Well, not so much. The increased efficiency of the higher cr means that more heat is converted to work in the power stroke, so the exhaust temp should be lower, all else equal. This will result in less expansion at the exhaust, and higher spool.

So what you just said is that heat does make the turbo spool after all. Thumper - I guess I don't see the discussion as being that far off topic - before you can tune for better spool (or better anything) it helps to understand what things have an effect on it.

Actually, that's the swap I really want to do... SR20 in a 308 (okay, not the Dino). Get the looks and handling and probably about twice the performance of that stupidly expensive wheezy 1980's Ferrari 3.0. Just seeing the look on the other Ferrari owners faces would make it all worthwhile...

FWIW, my block is the original N42 (i.e., non-turbo) block that came with the car. It does have a nitrided stroker crank, forged rods and forged pistons, but the block has never given me any problems. Only slight drawback is that there is no fitting for the factory knock sensor, although I'm not convinced that they work, anyway... My latest dyno results

It's a moot point anyway - if I see the same characteristic with the GT42R, then I'll take a look at the spring.

Thanks' date=' guys. So many questions... I know you didn't mean it that way, but re: bling bling... Yes it's pretty, but everything in there does have a purpose Keeping it clean and shiny has the added advantage of being easy to work on. The orange tubing is firesleeve - it has two purposes - first is to shield hoses from high heat sources, like the turbo. Stuff that goes near the turbo or exhaust gets firesleeve. Second, stainless braided hose can and will wear away pretty much any surface that it comes in contact with. The firesleeve is also being used to keep the hoses from abrading things - actually kind of anti-bling, as many people would rather leave the shiny silver showing. The is only one fuel rail. The piece that is mounted to the valve cover is made from fuel rail stock, but it is being used as a manifold pressure reference for critical items such as the MAP sensor, fuel rail and boost controller. Everything else that needs vacuum is pulled from a second summing network that was integrated into the plenum - the aluminum hard lines feed this second manifold, and it supplies the brake booster and other vacuum accessories. The manifold is a Mikuni piece that was intended for their triple setup. Many of you will note that the Cannon manifold (or similar) is usually considered more desireable, due to its straighter runners. I chose the Mikuni piece simply because it gets the TBs up higher, leaving more clearance for the turbo. BTW, the head flow numbers I quoted before were taken with the manifold, TBs and velocity stacks in place, so I don't think it's hurting me too much. The TBs are TWMs, and the plenum was my own design - I cut all of the pieces to fit, bent the outer housing on a sheet metal brake, and had an accomplished welder weld the seams together for me. The Elgin cam was ground on a new billet as far as I know. I did supply John at Elgin with a great deal of info, down to head flow numbers at 0.100" increments. Don't know if that helped get me more attention or not. Yes - I'm running a BHJ damper. Ignition timing was approx. 26deg from the onset of boost to 5000rpm. Then it ramps to 29deg at 7000rpm. Fuel pump is a single Bosch-style pump that I got from Kinsler - flow tested to provide 300lb/hr at 70psi. I run a Kenne Bell Boost-a-Pump to increase the supply voltage (and thus flow capacity) when on boost. The intercooler itself is routed normally for that type of intercooler - both input and output pipes go through the rad support on the driver's side. The tricky part is the cold air intake. I use a radiator that is 3" narrower than the stock piece, and pull my intake air from the resulting gap. You should be able to see the ducting for this in the pics I posted before - its the thing with the 6" orange tubing in the middle of it. The air filter is integrated inside the tubing. The spoolie jobbie was an experiment that James helped me out with - it looked promising with the Isky cam, but the more aggressive Elgin cam didn't like the added backpressure at all, so I am not currently using it. Maybe if I had a [b']much[/b] larger AR... As far as James's numbers go, remember that at the time his dyno runs were done we were pretty close on power (I was at 467rwhp, but had the added efficiency of the manual trans). He has since moved on to a new car with an RB. Also, I should let James speak to this, but I'm pretty sure he went to twins because he likes to be different and likes a challenge. He never ran a T64 as far as I know. Well - hopefully that answered some of your questions - let me know if I left anything out...

That would be this little guy: ...still trying to figure out how to fit it in there, along with the requisite 4" exhaust...

AFRs under boost ranged from 11.25 to 11.8 at 7600rpm, injector duty cycle was ~88% on 72lb injectors I gave up on the electric pump and fan after trying everything I could think of to get them to control my coolant temperature adequately. I went so far as to try using a Kenne Bell Boost-a-Pump on the water pump, which bumped the supply voltage up to ~16V when the temperature exceeded 195degF. Didn't help. Tried the same with the fan, which helped a little, but when I still saw coolant temps rising after a short boosted run on a 70degF day, that was enough. Put the mechanical pump and fan back in and never looked back.

It's an R230 with a KAAZ LSD

Ahhhh... the South Florida Performance header. Brings back many memories. The final product ended up quite good, but there were many many frustrating moments in the buildup of that piece. If you were to take your car to them and leave it, they could probably do a decent job, but I would not recommend trying to have them make you one any other way, unfortunately (actually, I seriously doubt that they would be interested in making any more, anyway). Joel can probably fill you in on some of the horror stories, too...

Thanks' date=' guys - I guess it's been a while since I posted the details on my car... Engine: nitrided/balanced stroker crank Cunningham forged rods, 5.300" Diamond Forged pistons, 87.5mm ceramic coated N42 head, polished and ported - 209.5cfm intake, 135.2cfm exhaust at .540 lift, 25" vacuum, combustion chambers and exhaust ports also ceramic coated the combustion chambers are still open chambers - no detonation problems so far 7.5:1 cr Elgin cam, .536 lift, 237deg@.050", 112 lobe centers TWM 45mm ITBs, custom plenum with internal velocity stacks T64 turbo, .84 AR o-trim turbine custom (SFP) log-style turbo header HKS 60mm wastegate 3" exhaust, seperate 2.25" exhaust for the wastegate Electromotive TEC-II, LM1 wideband Trans/Clutch/Diff GForce T5 gearset housed in a modified Datsun T5 case Clutch Specialties clutch (ACT 500lb-ft pp with sprung hub sintered iron disk) custom driveshaft R230 diff, KAAZ LSD, Modern Motorsports Moser halfshaft and stub axles Here are a couple of pics, I should be able to dig up more if anybody wants to see them. BTW, since these pics were taken, I have given up on the electric water pump and electric fan - today's pulls were done with the good old-fashioned stock mechanical pump and viscous-coupled fan. [img']http://home.comcast.net/~tzwicky/pics/Engine_090.jpg[/img]

23psi, 94 octane Sunoco pump gas... ...so how do you spell booya, anyway? ***EDIT*** The pulls were done in 4th gear (1:1), and the corresponding engine rpms are as follows: 80mph = 3870rpm 90mph = 4340rpm 100mph = 4850rpm 110mph = 5320rpm 120mph = 5790rpm 130mph = 6300rpm 140mph = 6770rpm 150mph = 7230rpm 160mph = 7750rpm ***EDIT*** ...the first graph was the best pull - the second shows a very similar pull that continued to 7600rpm (I quit too early on the first one). The last pic is a comparison to my last trip to the dyno about a year and a half ago - blue=old red=new The main difference today was the elgin cam vs the very mild Isky cam that I was using before. The ignition pickup for the Dynojet was a little flaky today, which is what was causing the spikes in the torque reading - It appears that the torque was maxxing out at about 470 lb-ft or so. Sorry if I sounded too cocky - I'm just pretty pumped by the results.

Isn't it still the other way around? I thought that n-series heads (like most early NAs) were dished, and the p-series heads were flat tops.

I had a similar problem with my McLeod TOB - I had used Castrol LMA (DOT 4) fluid with mine, in spite of the fact that they called out specifically to ONLY use DOT 3. I had assumed they just meant not to use silicone fluids, since DOT 3 and 4 are supposed to be compatible. I replaced the LMA fluid with some cheapo STP DOT3 stuff and it's been fine ever since.

Sorry - 24psi on 94 octane pump gas. TEC-II EFI system rev limiter at 7200rpm ported and polished N42, 7.5:1 cr stroked to 3.0 litres I don't have misfire problems at this (0.030") gap, so I don't see much point in trying to widen it - not much to gain and a lot to lose.