Doug71zt

Kind of sounds like a booster problem, But definitely remove the stock bias valve in the rear brakes if you are using the Wilwood adjustable one. No telling what the combination of the two valves is doing to your rear brake pressure. Some good reading on brakes http://www.stoptech.com/technical/ Have you bedded in the brakes yet? If not, they can get a 'glaze' on the disks and really not be effective. You could read up on the bedding in procedure and then go out and try it. Good luck - Doug

Jared - They were Direct Connection/Mopar Performance pistons, I will try to find some specs for them - Can't remember if they are 87 or 88mm bore. They were reasonable - much less than my custom Ross pistons. I don't know if MP makes them anymore as a lot of D/C stuff is out of production. I'll have a lookie. Doug

Well - If you were running 17 psi and the pop-off was modded to hold 15, chances are it is blowing off. It does sound somewhat like you are describing. BTW- 17psi manifold is likely 19ish psi at the turbo, you are running on the ragged edge of destruction of the stock turbo - no joke! That is seriously overspeeding the turbo. One could get the stock compressor map and work out by how much, but I don't think one would want to. This is also probably why the recirc line keeps blowing off of your BOV, the air temp coming out of the turbo is probably around 275-300 deg. The Nissan L28ET sure is one tough engine...... Doug

Do you ever get wheel hop with your car? I had a 383 5-spd S10 Blazer that had the same problem. It would wheel hop and bust the retaining pin for the spider gear cross-shaft. It made a really weird noise as the pin worked it's way out and started hitting stuff in the diff like the end of the pinion. Eventually installed LSD and reworked the suspension to get rid of the hop. Doug

Welcome Austin - You might want to rethink the exhaust side of your turbo. A full T4 with 1.0 A/R is going to be a laggy beast on the 2.8l. What trim is your exhaust wheel? I think that the most popular T4 hot end used here is a P-trim wheel with .70 - .80 A/R. Usually with a 60-1 compressor. HP and 1/4 mile times are wildly varied - depends on the overall balance of the engine systems and tuning. My current 2.8 runs 12.2 @ 116 with slicks, 12.7 off the street at 15psi. What EFI/timing control are you going to run? You are going to need some way of retarding the timing under boost. 12:1 rise rate on the RRFPR sounds a little high - 30 psi base will get you 126 psi fuel pressure at 8 psi boost. I think that's not going to work very well. If you are going the budget route, I would run the Z31 efi system and maybe talk to JWT or Bernard about a custom chip. I don't think that you will even have to search this forum, just read back through the old posts, it's all good relevant information. Good Luck - Doug

I was planning on using ferrous guides in my new engine, but Dave Rebello told me to stay away from them in the Z head, he said that they have never worked right for him in that application. He recommended standard old off-the-shelf stuff for my P90. I've never had any problems with the bronze guides in the Z head, but I have never built a 400+ hp L engine before. I guess I will see... Doug

Pete - Was it Steve Webb? He had been running a Typhoon turbo for a while - not sure of the present state of his car. I had a look at it in Arlington when I was at Bell Helicopter for a course about 8 years ago. He was putting down some pretty good numbers with it. FL - I'll try to find the links for this. http://zhome.com/rnt/StealthZ/swebbA1A.htm There are couple of parts to the story on his car. He seems to have got it on there with just a spacer to make the compressor clear the manifold and some clocking/ messing with the wastegate linkage. You could probably email him for the specifics. He's a nice guy, an aircraft mechanic, was working on Learjets when I met him. Let us know how it goes - Doug

OK - It's official - This post has gone completely off-topic - LOL

Speaking from personal experience, it isn't the lack of car control skills that causes the big problem in younger drivers/hot cars senarios. Judgement and self-control develops with age and experience. The realization that public roads are uncontrolled enviroments and that road hazards / pedestrians / semitrucks / dumba**es that can't drive exist out there will eventually happen. You're a smart guy, evidenced by the mods to your car, so you probably already know this - age will teach you to listen to that little voice when the red haze sets in and back off the throttle a bit, give yourself some space and resist the peer pressure to perform over your or your car's limits. The pack mentality causes lots of problems on sportbikes - this I learned the hard way also - trying to push my GS1150EF to keep up with the then-new GSX-R's. The GS had big power, but was also a big pig that didn't have the moves of a Gixxer. Especially with me on-board. Hopefully, you will also decide that 9/10s really isn't the best pace on the street and will stick around with us awhile. But - then again - some people never learn that one, no matter how old they are.... (Trips, falls off soapbox) Hope you do OK by the insurance adjuster. Doug

That's one of the reasons that Max-effort turbo cars have breather catch-cans. J/K - There really isn't all that much area for the boost pressure to act on the bottom of the valve seals, so the net force is very small. Doug

Sounds like the pop-off valve venting. Mine went in the trash about a week after I got the car running. Sure - its a disaster-preventer, but some things are sacrificed in the quest for more performance. Remove it - plug the hole with a pipe plug and take the car out for a ride. Then you'll know. Good luck - Doug

Buy it back from the insurance co. , step back, reevaluate, if need be, find another chassis. Big thing is that no one got hurt. Believe me, you'll find another Z. You're not the only 17 year old to wreck a Zcar I got my wakeup call street racing a Mustang 5.0 in '87. A bumper tap put me into a hydro pole at 70+ mph. Very very hard for a teen to explain why the front and rear end of his car are separated by 200 ft in a 30 mph zone. You may find that when you start drilling out the spotwelds to replace panels, the chassis isn't as bad as you think. My car had no front end to speak of, but was back on the road in the same summer. It's a setback, but not the end. All part of your higher education in the school of hard knocks/tough luck. Good luck - Doug

It's only 96 off of my VIN - It's a 71 alright, who knows what happened to it before some bodyman got a hold of it. My first 72 240 had a 77 front end c/w that godawful 100 lb bumper.

That set of pictures is from an importer's website - I was trying to remember which one, maybe Toronto or Montreal area. I've been looking around a lot lately. Danger Will Robinson!

Hey Richard - A friend of mine has the bottom end built (for 3 years now) but not installed. His project is on hold for other reasons. He used Dodge 2.2 forged turbo pistons and 240 rods and crank in a F54 with a P90 head. With the overbore, it comes out to a 2.6 liter. It wasn't an expensive build, FWIW. It was his opinion that the RB26 was the best optimization that Nissan came up with, so why not emulate it. He is planning on twisting it to 8K. I myself like the 3.0 liter route, which I am currently building. Redline will be 7 or 7.5K for mine, depending on how much money I put into a dampner. But, then again, my next upgrade will be an RB30 with RB26 head and a single turbo. I guess you can tell what side of the fence I'm on in this issue. I'm interested in seeing the results - a dyno chart, seat of the pants, etc. I've been at my buddy for 3 years to put his car back together in order to see how it works out. He has a custom 321SS manifold with external WG, GT3040R turbo, custom intake similar to James' with a 70mm TB. All this stuff is just sitting there, waiting. You will laugh at this, his 240 has a Dodge Cummins IC rammed in the nose, Required a little trimming of the framework forward of the rad saddle and deletion of the hood hinges. It just looks nasty in there. My local group of Z guys has a machinist, tool and die guy, millwright, mechanical engineer and aircraft engineer. Sorry - a little OT. Doug

John - Sorry - I said 'yes' at the start of my post, but I mis-read your post. I had it in my head that you were going to coilovers. I think that you will need a spacer, but it won't be very thick. A slip-on one may do the trick. Doug

Yes - on the F54 block, it is right close to that area. I don't have a picture handy. Doug

The stock location on the F54 block L28et is on the passenger side, quite high on the block between cyl 4 and 5. I run a GM knock sensor with my SDS, but I am going to change to the stock nissan sensor when I change the engine. The GM sensor has a different tuning, and is picking up noise (Valvetrain?)and backing off the timing. I have it set so low in sensitivity that it is pretty much shut off. Can you adjust the sensitivity of your knock sensing on the HPV1? I think that a higher mount would likely work better for you. Closer to the source of vibration. As with you, I know when I get a bad tank of gas. I just back off the timing a couple of degrees under boost until the next fill-up. SDS is nice that way for quick adjustments. Doug

Mayolives - I just ordered a set identical to Speeder's from Ferrea. You may be able to get them on the same run as mine, cutting the order time down a bit. I ordered P/N F1839P for the intake(stock size) and P/N F1842P for the exhaust (1mm oversize). I was looking for a quality SS valve for quite a while till Speeder turned me on to Ferrea. The only other ones for the P90 are made by SI and Dave Rebello recommends not using them as the stock valves are a higher quality. If you are not shooting for 400HP or over, it is the consensis that the stock valves will be fine. Manley used to make P-90 valves, but is not interested in making just one set. They would like you to order 100 or so of each design, in order for them to tool up. Hope that this helps you out. Doug

Yes - With coilovers and Z31 hubs, Z32 16x7.5 wheels fit very well. I run that setup on my car. If you are using 87-89 hubs, they are a little different backspacing due to the slip-on rotor design. I have a set, but I haven't tried them yet. On the rear, you will need a wheel spacer to match up the track width to the front, as the rear hub will sit in very close to 1 inch compared to the front (depending on the thickness of your brake drum or disc flange. I use a bolt-on 5 lug to 5 lug adapter, which also has a mount for my Wilwood brake rotor. Overall, I'm very happy with the 5 lug/coilover combination. Z31 wheels have a different offset (around +28- +30) They will need a spacer on the front to clear a stock spring. I'm not sure how wide the spacer will need to be on the rear, easiest way to work out the spacing is to get the hub drilled, and then shim the wheel out with thick washers on the lugs, to determine the width of your required spacer. I set up my car to accept the Z32 wheels because a wheel with that offset is very common in the aftermarket (FWD offset, Mustang, ETC), where a Z31 offset is more rare. Doug

Zline - The engine in my 01 Max has a front sump.

I run 26x9.5x16 QTP DOT with coilovers on my 240 and they are fairly tight in the wheelwell. You are trying to go 1 inch wider with stock springs. I don't think that they will go, but I have no proof that they won't fit. Maybe someone here's been down this road. Good luck, Eh! Doug

Trust me - I know - aircraft are very, very flexible. They have to be or they would crack themselves to pieces. A Boeing 747 wing has 6 feet of deflection at the tip, from static to rotation speed at takeoff. Another tip - If you don't like high levels of NVH - don't go for 13" 6 piston racing brakes on your street Z. You will never get them up to operating temps on the street and you likely don't have enough HP to use them on the track - the 240Z weighs 2300-2600 lbs - it doesn't need 13" 6 piston brakes. 3500 lb Mustangs, Camaros, and 300zx TT's need 13 inch rotors. I've treated the AZ 11.5" kit very very badly on a short road course and it didn't fade, so why add unsprung weight to your suspension? Ultimately - It is your car and your choice - but I think that the 'custom' parts that you want are going to be very expensive and offer no change in performance from what is available 'off the shelf'. BLING BLING Doug

Did the Rx-7 come with ABS in '91? If it did, you could use the same style of system to run your speedo - You may have to go aftermarket on the speedo. What are you using for VSS for your engine control computer? Doug

Thanks Richard - If you want to move this thread to the turbo section, it probably has more relevance there. Well - I'm attempting to get maximum compressor efficiency in the torque peak range for this next engine, as that's were my current engine will start to ping first as I advance the timing. I am also going ball bearing, so hopefully the new GT compressor maps are accurate enough that I can do this. I was all ready to go GT40 82mm 56trim, but I stepped back and thought about it a bit. As my calculations go, it is too big for the L30. It would be great for an RB26 or RB30 with more RPM potential. That compressor is in it's most efficient range between 6-8K. It's not that efficient between 4-6K where I'm looking for better. I'm accounting for intake losses in the feed to the turbo, IC losses, and was hoping to get an accurate VE number to finish it off. Off the top of my head, I think 80-85 will be close, but it's just a WAG (Wild-A** Guess). My current favorite compressor setup is a GT37 wheel, in a T04S housing. 76mm, 54 trim, .7 A/R. It fits my HP goals (400ish) and has a nice wide 78 % efficiency area. It also gives me more surge margin, as the GT40 wheel has some problems there. I guess I am just trying to cover all the bases before spending the big dough. The GT 40 wheel is being touted as the fits-all-engines, world's best wheel, but for what? If I was looking for all topend, and was reving to 8K, I'm sure that it would be the way to go, but for a do-it-all car (daily driver, dragstrip, Mosport) - I think that it would be not the best compromise. Even my T04E 60 trim is too big for the 2.8 - I can induce surge pretty easily. But - I'm learning - max compressor for a stage 3 wheel should be a 50 trim T04E and my 60 trim should have a stage 5 wheel driving it. Knowing what I know now - I would say that the best all-around moderate hybrid would be a T04E 50 trim, .60 A/R with a T3 .63 stage 3 wheel - maybe an .82 on the exhaust for more flow. When I get it up and running - I'm going to instrument it and datalog - them I will prove or disprove Doug's theory of compressors. Cheers - Doug