John Scott

For those of you who have had your engines dyno'd how much is the going rate. I'd like to put mine on a chassis dyno, since I'd rather not pull the engine. Are the coast down subtraction figures accurate for converting to flywheel hp? Also, since I'm playing with some high boost lately, how do you figure how much race gas (114 octane) to combine with premium (wimpy 91 due to our altitude) to acheive a desired level. 1:4 for 97, 1:1 for 103 ?? I know octane boosters are just band-aids, there's no substitute for good gas. Running more octane than you need, I've heard, will hurt perf. Still I don't want the insides of my engine saying howdy to me due to detonation. My effective comp. ratio with 7.5:1 @ 16 psi is around 13:1, the max allowed for pump gas. Intercooler will allow me a 16:1 effective c.r. safe on pump gas, but for now I need the safe gaurd of higher octane since I'm seeing 18psi w/o intercooler. What comp. ratios are you high compression racers running, what kind of gas? JS [This message has been edited by John Scott (edited April 27, 2000).]

Mark look into the complete engine packages for sale, i.e. turbos, engine computer and all. I've seen both the GN and TY/SY engines come up for sale. Scottie has done the swap so he could give you info on wiring and set up. If you go the procharger route, I'll give you all the tips I can, especially if you go 4.3. (comp. ratios, pulley sizes, jetting, etc.) . Keep us posted. JS

I think you could turn a stock Viper into a worm! The potential for top speed wars is in the favor of some of the projects here. It would be nice to know that a major auto builder already added/tested the necessary parts though. JS

Ray, Mark, The procharger is a great unit that can be adapted to many induction systems. I chose the carb blow through because I am on a budget with my car. I'm sure FI is the hot ticket, but this works really well. A regular holley carb (mine is a 600 dbl pmpr) has the choke horn milled off, the area where the choke linkage passes through sealed with JB quick weld, heavy duty needles/seats, and neoprene floats. Thats it. No carb enclosure like Paxton.(No room on a six either) I would recommend a larger stud tapped in, I blew mine out at full boost! The fuel can be handled by a modified mechanical pump, or an electric that is regulated by boost/vacuum. I also have a big pressure relief valve that dumps boost when its not needed, saving on heat transfer, bent throttle blades, and bent impellers(not an issue w/ billit)I run the mallory 140 w/boost regulator, 5 psi idle, pump then increases w/boost. So far so good. The 600B(billit) is good for 60,000 rpm which will give over 20 lbs. They have units that make this look like a hair dryer if you need more! Mark you were wondering about this set up over a turbo, both will have there benefits and shortcomings. The centrifugal chargers are the most efficient superchargers made. Adibiatically, they don't heat the air charge as much as other systems i.e. roots, turbos. Their boost is linear and once you have your revs up, power is instantaneous. On a low compress. v6 w/big cam the bottom end is really dead. Don't get me wrong it will still stick a 4 sec 0-60, just kind of lazy for the first second. If you run a stick this won't be an issue. I would consider both systems before I'd choose. I feel the Turbo with the computer/+ FI is much more complicated, but probably will give bigger hp#s throughout the rpm range. True you get some lag, but the potential of a turbo system is amazing. Quiz Scottie-GNZ on the buick system. Hes got experience here. If anyone wants more info on the procharger check out their website www.procharger.com Their tech people are great to work with. I'll be glad to answer any specific questions that I can. JS [This message has been edited by John Scott (edited April 26, 2000).]

Yes, its an ATI 600b. Blows through a modified holley. 18 psi last night! Gear noise is pretty loud, but it sounds cool! I love it. If you need more info, just ask.

I've read the JTR opinion of the rear sway. Said the inner rear tire lifts or lightens on corners. Posi rears a benefit. So, thumbs up so far? John Scott

Myron, isn't Biondo running 3.15s? I'm not sure if its even a Datsun rear. ?? That would sure help your revs. If no one comes up with a good asnwer I'd call Motorsport. They've always been cool with the Z questions. 1 800 633-6331. All the techies own Zs. Someone there will know. John Scott [This message has been edited by John Scott (edited April 23, 2000).]

Could it be your cell isn't venting? If it starts out at a good pressure than falls, maybe its creating a vacuum in the tank. If you were to open the filler and it came back up... Just throwing ideas out here. Good luck. John

Hang in there Mike. You're going through more than your share of frustration. Relax and forget it for a while. Sometimes when you step away you'll figure out better solutions. I think you have one of the most sophisticated projects going here, and with it your're going to have more troubleshooting than the rest of us. Its going to be an phenomenal car! Good Luck! John Scott

Scottie, BTW did you get your rear welded? When do you plan a track run? John

I was going to say something about a Bentton(sp) BMW race car that had less than 1.5 litres, over 1000 hp that achieved wheel spin at 179 mph,...but nevermind. John

Incredible! That's all the lift? I have pimples bigger than that! Ahh the wonders of forced induction! John Scott

Thanks Scott!

Scott, I'm also curious about the Ty/Sy cam profile. Non of the sites I was into had the info. Do you know the specs.? hp/tq peaks? I'm amazed what these trucks do with low rpm #s. Thanks, John Scott

I got to jump in too. I've seen well over 160 in my stock bodied Z. (5600 rpm 3.54 rear .7 4th gear with converter locked, and still pulling HARD) It didn't take very long to do and even shorter to realize how stupid it was. Yes you can go really fast in a high hp Zcar. Only a few here are taking the time to make sure the cars can be driven at these speeds, not merely attain them. Its fun to know your car can pull the high #s, but next time I'm that far into the triple digits, I want some areodynamics, BRAKES, Z tires, and tighter suspension. Yes the faster you go the more hp it takes. Lots of magazine articles state "areodynamicly limited" to the top speed #s. Most of the top end shootouts w/6 speeds are done in 5th. Unless you have the hp to pull it, the .5 ratios are just to let your engine relax between showdowns. John Scott

I bet you still spin with the 3.54s too. What are your trap speeds? Any way with the 3.54s about a 25 inch diam tire you should be running about 5000 @ 100mph in third. I've got a 700 also. Best automatic I've had! ...but going to a standard! John Scott

New pulley is on. Much higher whine from the blower gears. Also more whooshing from the relief valve. Still trying to find where boost/rpm is. Everything is happening so fast I dont have time to look, steer, shift. I glanced down at the gauge to see 16 psi and heading north rally fast before I shifted. I think I was well below 6000 rpm. No detonation on pump gas! Thank you 7.5:1 pistons! I'm so used to popping it at 7000 this will take some getting used to. I'm right, my tires think I'm the biggest #$@*! ever. John Scott

I think they have a different crankshaft, pistons,...Scottie Where are you!! He'll know! John

Scott, I'm in love with the 4.3! Everything chevy makes for the small block will fit in there. Very successful racing history as well. No chips on my motor. Just trial and error. No detonation tonight at 16 psi!(no where near red line, On pump gas!) Pretty wild ride, can't keep up with boost gauge, tach, and trying to keep it straight! John Scott

Pete, how much is the "enhanced T5? It seems one day I'm ready to go with the builder I found, then the next someone is telling me they just trashed a gear in their WC. I've been assured that the trans will live in my car if I don't run slicks or slam the gears. Now I'm not sure I want those limitations. He told one customer outright, if you drag race the trans. you'll trash it. I know the WC has better deeper hardening, and bigger bearings than the old T5s. This guy designed the countershaft support that really helps. Sounds like your builder addresses many more aspects of the trans. Tell me more when you get more information. Personally, I think I'm getting ready to suck up and save for the T56. Fed ex left a delivery notice on my door. My itsy-bitsy blower pulley is here.

Scott, I'd like to read the SAE papers on the SY/TY engines. Where would I find the info? Thanks, John Scott

Thanks for the info Scott. The hypereutectic pistons, (high silicon content) though much better than the stock pistons, are still not up for a lot of abuse. Forged is really the only way to go with a blown motor. Have you done anything to the engine on your Syclone? Tell me about the content in the Ty/Sy bearings.( I went to a "H".) John Scott

Brian, I've been hashing over the same dilema. I've been told to avoid the T5 unless its a World Class T5. I believe these came out in 88 up. I've been told the older trans had softer gears and smaller bearings. I've decided to go with the weight savings and run one. I found a guy who is going to build me one NEW (case, gears, everything, choice of gears, tailshafts etc.) with the countershaft bearing support. I've been giving all my engine information along with some dyno tests of similar engines. He thinks it will hold fine. I can give you his name, but its not going to be as cheap as a used one by far. www.gearzone.net/t5.htm If you are planning a really high hp project and/or ever plan on running slicks and powershifting, I'd save for the extra expense ($2300 new!)and reliability of the T56. In the right years, its a hell of a transmission. John Scott

Come to think of it, I did that to mine, but luckily I read the instructions. (sometimes we get lucky) Along time ago. As I recall they wanted a return line as big or bigger than the supply lines to run correctly. (Maybe its just mine with the boost regulator). Glad you're getting the bugs worked out, Mike. Should be ready for some action soon??? John

You could always put the beer cooler up there. Just a thought. John