jack46

I think it is safer to assume they are to small and add additional diodes. Extra diodes will simply be capable of flowing greater current. If the diodes are too small they will burn out. But it will continue to work so you won't know they failed. Diodes are cheap and when doing it why not make it more robust and unbreakable. PS in many instance the diodes are not used! The failure when diodes fail or are not used will usually cause the relay to weld and leave the fans on. Not my idea of good design and not what I do. So if there is a failure you pull the relay and replace it. I know many who don't fuse either ASSUMING the relay will act as a 30 amp fuse. It won't. The relay is NOT an effective fuse, and can allow a fire, because the relay could fail welded and with no fuse it will flow current until something melts. This is often after a fire has started. PPS A diode is a one way valve of sorts so tends to conduct when voltage is applied in a certain polarity. http://www.fairchildsemi.com/ds/1N/1N5400.pdf Reverse voltage according to the datasheet is 1000 volts, peak current is 200 amps so it is a fair choice, but I would put two in parallel or an even larger diode to be certain. I believe in overkill especially when cheap as in case of diodes and wire size.

EVERY connection adds resistance. Resistance results in voltage drops. E = IR from ohms law. You want battery voltage applied to fan, so you want to minimize voltage losses. I always connect HIGH current devices from alternator, or battery through fuse, then relay, and finally the load. The low current side can be powered from almost any circuit. The relay will operate fine with less voltage since lower voltage mainly affects the time it takes to close. Then holding current is much smaller. I used dual 10 gauge wire to feed power to the fuses. I had my relays out front, but will move them inside and probably use two relays on high fan side. I also used this voltage to feed my headlights and used the old wire to power a relay. Thats why I had it up front. I had some problems with rain so I will relocate all relays inside of car, and might as well add second 30 amp relay for the fan high circuit. Starting current on any motor is always extremely high. PS and yes I also have a diode to minimize back emf. The relays I bought have them in the wiring connector I bought with them.

Well which are better to date blonde or brunette? No right or wrong answer, it is a personal choice. I would start by determining what you want, and how much you want to spend. udget is ALWAYS more than estimates. If you want to be unique, fast, or whatever is your criteria go for it. In the end you will have to live with it. Just be as realistic and honest as possible with what you want. Good luck PS I had a 305 Z for ~15 years and loved it. Was a daily driver and was fine until I got the racing bug. Then converted to 383 then LT1. That is also a MAJOR consideration more power more breakage and problems.

Fastest u joint halfshaft Z I have heard of, no less seen a video of.

Well I wasn't either but I paid $18 for adapters and welding to rail. I got a block of aluminum for free so minimum and will prevent a problem later. Actually I could simply run a single line and probably get by but...a second 3/8" brake line from tank to front is cheap and easy to do before the engine and tranny are in. I would bet I won't exceed 500 RWHP but now I know fuel delivery will be fine to OMG levels. I have a 9" and hate the work of tubbing it for it. IF I break CV's I will but I hope to make it without. Q45 seems like the way but also not cheap. Power breaks parts and costs. From header thread I would consider buying those, I'm sure your friend does great work, but a proven product is tough to match. UNLESS he can make 1 7/8" Good luck

Hanns I'm not certain, but some fans if both fields are enrergized will burn up. Since I have never been told for certain if the Taurus will I power only one at a time. The following is a schematic for the fans if you wire as it is if both switchs are on the high speed field is energized. It is wired Hi or Low and not both. If you want a second relay for high you simply parrallel in a second relay on high side of cricuit. Email me if you want me to draw circuit for you Good luck

What is a part number and address for >1 5/8" headers? I tried and can't seem to get their site to open. I have 1 5/8" and they are fine for lower hp but restrictive at higher hp Thanks

Well not sure where the inlet will end up... But I will tell you the stock fuel system on an LT1 runs out ~540 RWHP. A friend has a dual turbo LT1 and single fuel line will not make it. We modified the rail by putting dual fittings on rear of rail. Then made a fuel block that handles dual 3/8" fuel via 3/8" brake line and stock regulators. Setup will flow a ton I plan on using dual Caprice pumps since they are ~$50 each and both should flow ~700 RWHP. You could 'T' into front of rail with another line but that wouldn't look as good and cost as much or more. I would love to use 230, but IMO too EXPENSIVE. Since I already have spare R200's and 300 CV's will try it (~$250 for adapters). I have a 9" if that doesn't make it since I doubt the 230 would take that much more, and the limit should be the 8.5" sicks. I hope they will break loose at launch and stay together. I just hate the thought of the tubbing, work work work work. The 9" is cheaper than 230 just takes ALOT of work. Also what headers are you running? I have a large set 1 7/8" that will flow supercharger nicely. Good luck

Are any of those headers >1 5/8"?

seems there is no absolute. I have run 1.63's 60 and not had a problem. The Z had a 383 and I launched ~2500, I then converted to an LT1 with ~1500 stall. The LT1 managed only 1.8's yet I melted two halfshafts? Seems there is little logic in when they break. I converted to 280 CV's and changed to a larger stall and cam and will return to track in a couple weeks. I am expecting the half shaft problems to be history and to run alot faster should have ~350 RWHP I have a second Z I will try 300 CV's on and will run ALOT more HP to. Good luck

I'm installing a kit from a Camaro into a 75 280 Z. From initial measurements the charger will hit the lower rail. Fitting it in is not my main concern getting the rear end to take it is. I will start by using CV joints on a 3.53 setup with braces to help the differential taske the shook of launch. I hope the car will spin enough to allow the unit to stay together some say yes others say no way. I found a used CV conversion for $150 so figure I will give it a try. I have a 9" but the fabrication is nothing I look forward to doing. Good luck

Stock LT1's torque curve is extremely flat. One published dyno showed torque 328 at 3000 and 295 at 5250 with peak of 331 at 3900. The horsepower peak was 295 at 5250 on a chasis dyno. The Rev limiter in stock 95 Camaro was 5886 in first and 5805 in 2 - 6. Many simply increased the rev limit and shifted at higher RPMs. I had a small 214/218 cam and shifted at 6450 in first because the engine loved to rev and it produced the best times. If you enter my cam on a desktop dyno it suggests peak hp at 5500 and peak torque at 4000. Depending on your engine setup it will be totally different than someone elses. BUT as a family LT1's like to rev and develop a BROAD flat torque curve. I just changed to a 224/232 .510/.530 because in my Z it does well with headers and 4.11's. Good luck

Ok I have a welded R200 3.54 wanted to use CV and Ross CV adapters. Hoped it could take LT1 with Vortech and 10 psi. I will have small slicks 8.5" wide to let it spin some on launch, From your reply seems the setup can not take the power. I expect good power at launch with stall getting ~2500+ Thanks fro reply

I bought CV's axles and conversion kit for a 280Z. The best information I have found is the stub axles are the weak point, so since I used 280Z axles will the setup hold a supercharged 383 setup? I see others running turbos, but not sure how it will take a SC >2500 launch. I do plan to use 8.5" slicks so it will spin some on launch. I think it should be less than many do with built 350's and NOS. Thanks for any thoughts

Yes rewatched your video a few times, and I see where you redlighted, and shift light is on a while in second. I swear I saw 5.96 but I still say WILD ride. I still wonder how you will plant more power, and laugh thinking your ride is getting 'normal' to you. I change my mind constantly on charged 377 LT1, but will watch your video as inspiration. I plan on running maybe 10 LBs boost so 6.8 is probably realistic especially for first year. I know 6's are hard and a tenth at the level is a struggle so I hope I am keeping expectations real. Thanks again for inspiration. Good luck with increasing boost.

Well my eyes are very bad but 6.50 with that slippery launch is IMPRESSIVE. I have to wonder how you will plant more boost but obviously you know what it can do. I'm slowing putting together a supercharged LT1 with 9" I hope to be <6.8 maybe later this summer I will be newest person in 6's Thanks again very nice setup and great video I downloaded it, hope you don't mind. I consider that one of the best 'amateur' drag videos I have seen!

Damn That is wild ride to say the least! What time was in video thought I saw it but wanted to ask. VERY impressive setup and definately smooth power!

Email me if you still need help.

Here is a link to what you will need to buy or fabricate. Click me This is also discussed in a thread alittle further down. Good luck

Ok I have a T350 and a 383. I had an opportunity to get an LT1 and will be putting it in. While I'm at it I'm considering going and changing to the 4L60E tranny for overdrive and computer control. I know I will need a 2" shorter driveshaft and relocate my mount, but will the transmission hump have to also be 'adjusted' (ie enlarged). I have a 74 260 with the distributor on SBC close to firewall (HEI might fit in) and want to update but dont want alot of hassles. Also I was told to use a torque convertor from an S10 to get ~1500 have others had any success with a convertor? I know with a T350 I nevercame close to advertised stall RPM. Thanks

The opti spark is NOT complex. The schematic is here (click below) Opti Schematic (Click me) There are mainly three signals from the opti spark. The output of the coil to each plug. Put a timing light on coil and if it fires then it is ok it is controlled by a pulse on 423 white (from ECM) if no spark AND there is a signal on 423 then module is bad. Of course you can check that the rotor and cap are transferring the spark with timing light also. If there is coil spark in and nothing to plugs then rotor missing or problem with cap and rotor. The other two signals are the high and low resolution signals from the opti spark (B20 and B2). They provide information to the ECM to allow it to know the crank position. The ECM uses the position to fire the injectors, and to determine when the plugs need to be fired. Basically the high resolution allows the ECM to control engine events, since there are 360 pulses on wheel and using rising and falling edges allows the ECM to precisely control events. The low resolution includes information on which cylinder is approaching TDC. For trouble shooting all you need is to know is that they pulse when engine is turning over. You can display the pulse trains on an oscilloscope or simply see that they are varying with a meter. Hope that helps. Doing this should allow you to know if the ignition is firing or not, and if the coil is firing you could check that all plugs are receiving fire (with timing lite). Also determine if injectors are being pulsed. I suspect you are NOT getting fuel to the rail. Another test is to connect a fuel pressure gauge to rail on a 94/95 there is a shrader valve at the rear between the fuel rails. It is slightly off center and closer to the passenger rail. I would start with fuel pressure check then see if coil is firing, and injectors etc. Good luck let us know

Nice job! Im putting a couple LT1's in Z's one is NA and should be done in about a week. The other is supercharged and a 3.75 stroke 377 so should have a nice flat torque curve. Looking forward to getting em done.

Thanks for the inputs. I have one Z in area but of course it is a 77, and has sat in field for....I might add a sump or something in line to 'hold' some fuel to avoid starvation. A friend has an idea not sure if it is practical yet. Thanks for all the inputs. Will let all know where I end up I am focusing on finishing rebuilding the LT1 it had a bad rod and crank but for 200 can't expect alot. It is an oiron hgeaded one but I will put in a Camaro cam so should be a decent daily driver with punch. It right now has a 383 and 4.11 will start with a milder stall ~2000 effective and should do ok then change to 3.54

I'm changing to an LT1 in my 260. I am concerned about fuel starvation under hard acceleration. Does a 280 have better baffling, and will it fit in a 260? I plan to modify tank to accept a Vortech internal tank pump but prefer not to require 1/2 tank of gas to accelerate hard. Thanks

I should point out that I can not use juice or I melted the halfshafts. This next beast will be tubbed and have a Ford 9" so as far as stealth goes yes you will have a stock hood, but to hook the power the stock differential will go one way or the other. I have heard many taking more than I tried to put down, but I could NOT get it to hold my little 383 and a 125 shot at the track. On the street it would take it because it didn't hook. When it hooked it would last 3 - 4 inches. The 260 in pic weighs 2830 with me in it as raced that day, my next 280 should weigh < 2500 with close to 450 RWHP. So should be in the high 6's after I get it all setup