Scottie-GNZ

Not sure if anyone will find this useful, but when I race I only run with race gas. Here is a chart I found on the web and dressed it up a little and sorted it in order of the Motor Octane (MON) rating. MON is the key octane rating for racing apllications as opposed to (R+M)/2 rating posted on the gas pumps. Those of you running or considering running race gas might find this comparison useful. Especially note the specifications for VP C-16, rated as the best for forced induction. 117-octane is enticing but $7.50/gal, makes you choke. The 3 highlighted ones are what is available in this area other than at the track. The Sunoco Standard is $3.49/gal, so I mix it with the C-16 for about a 110 MON. Crank the boost up and hold on, without worrying. Race Gas Comparison

The Buick forum had a recent database crash and those files were lost. Sorry. Maybe someone here captured the link to the guys website and could post it.

or maybe drug-dealers

You are correct for questioning this as it is somewhat confusing. I hope I can help clarify it a little. -AN (Army/Navy) is a standard developed to match metal tubing. The numbers are 16ths of an inch which is why it is commonly equated to 3/8, 1/2, 5/8, etc. Rubber hosing was designed to fit snugly over a metal hose, IOW, a 3/8 rubber hose will fit snugly over a 3/8 metal line. That means a 3/8 rubber hose and metal line are not the same size The sizes Aeroquip is referring to are the id of the AN hoses. The confusion lies in what you are comparing that to. If it is being compared to a metal line, which just about what all cars are built with, then the sizes are equivalent. If it is being compared to a rubber hose, then...... Since just about all cars came with metal lines, I think it is correct to use the AN equivalent. Crap, I probably just made it worse

Not saying not to use it, just saying if you plan on making up to 550+hp, it is not required. To clear up any confusion, -10 = 5/8" and -8 = 1/2". Also noted you said the fuel rail is tapped for 3/8" (-6), so you need to address that.

1.968 is not bad but still a far cry from what a well set up Z with DRs is capable of. People spend big $$$ to gain .5 and that be gotten from perfecting the lauch. Keep that action going. They never expect it from a Z-car .

Unless you are planning to make the kind of HP the pump is supposedly rated for, -10 feed is totally unnecessary. FYI, I am running -8 feed and the original 240Z feed as my return. I do a -6 off the FRP and connect it to the Datsun feed with a tube nut, then -6 again into the fuel cell. Best buy on the market for a in-line pump is probably the Walbro GS392 rated at 225lph. I am in the 430-440rwhp range and do not plan on changing it if I add more HP.

....THE BIGGER THE RUSH!!! You make it sound like quicker drag cars are less fun . With the L28ET, the intention was drivers school on road courses and the occassional x-cross. That plan went to hell when I started testing the HP progress at the strip. Car is now being updated to be a better street car but main competition focus is drags.

If I guess the weight at 2800lbs w/driver, that puts you at 262rwhp, so yes, there is some tuning to be done for more HP. What was the 60' time? You said you can't get out of the hole and no surprise with street tires. I imagine you are probably giving away a good .6 to .8 with a really bad 60'. With more tuning and good set of DRs, you probably could run hi-11s.

By my estimation, the 320rwhp would have to peak at 6000rpms to only have 280lb/ft of torque. If you assume that is fwhp and use an optimistic 85% drivetrain loss, that would put the rwhp at 272 and peak power at 5100 would generate 280lb/ft of torque. Hmmm, coincidence? Only way to really tell is with a posted timeslip and weight w/driver. That never lies or have you wondering.

Stony, Jason had the perfect description and as a result the MPH would be slightly higher than the speedo if taken exactly at the finish line. I go back to what I said before and the formula bears me out, Given the same HP and Weight, you cannot improve ET and MPH at the same time. A quicker ET means the car is spending a little less time on the track. The impact of the little less time is on the top-end where you have just that less time to build MPH. If the Supra did not bog and cut say a 1.80 (he had slicks or ET Streets), and you apply the 1.5x factor, his ET would have been around a more normal (for that heavy car) 11.60 and the formula spits out 123mph. That is a ton of MPH for an 11.60 but normal for a SupraTT. Mortal, err, normal cars running 11.60 would have about 117-118mph. 980mak, the "heavier" reference was in comparison to the Z-28 16x8s/slicks combo. The 16x8 are much lighter than the 17x8.5s and slicks are very light. That is the penalty you pay for going to a larger diameter wheel with wider tires. Just ask Terry Oxendale or Dan Juday what their wheel/tire combo weighs. As for why the 60' was so much slower (about .2 compared to my normal DR times), there are a couple of reasons. On the previous run that night, the car was backfiring during the burnout and fell on its face at the launch because the batt voltage was down to 9.5! A mad scramble followed to fix it and when I did, I just was not focused at the line. Those of you who run quick cars that launch hard know how important that is. The primary reason though is the fact that was the 1st pass on this new heavier, stiffer sidewalled combo and I just need time to find the right burnout/pressure/launch boost procedure. It is not a knock on going to big wide DRs. In retrospect I wish I could have stuck with the 16s but as pointed out several times, tire sizes are limited in 16s with 245 Nittos being the biggest, "normal" 15" wheels do not fit over the Vette rear brakes and certainly not the fronts. I do not have an answer to the exact effects of heavier wheels and tires, but going in I was willing to sacrifice a little 60' and ET to not have to stripe my shorts with the car wandering at 125mph. I just cannot get myself to put front skinnies on the car. One of these days I know I will have to, because I am probably giving away at least .2 or more in the ET becaue of the difference in weight and how much harder I could launch.

The only flying debris you would see are body parts. Remember, a rotary has no parts to fly apart

Another one of those age-old arguments . What I described is going to be more prevalent in turbo cars simply because, given more time on the track, (as a result of a slow launch) to build boost under load, a turbo car will generate more mph. Jason is dead-on when he says MPH is a product of HP. However, if you use a formula to generate HP from ET, MPH and weigh, and weight and HP is unchanged, you cannot improve ET and MPH. The MPH loss I am referring to is not huge, simply because ET affects HP less than MPH. Let me relate an experience that happened just recently. I make a pass with slicks, cut a quick 60' and the car goes 10.86 @ 124.39. HP formula say 430.6rwhp. Next pass I make a minor tweak to fueling and get a not as good 60' and the car goes 10.95 @ 125.59. Formula says 435.3rwhp, about what I expected from the tweak. More HP, slower ET but more MPH. The next time to the track, I switch to the 17x8.5s and 275 DRs, much heavier! I got an horrendous 60' and the car goes 11.17 @ 125.59 (not a typo, the same MPH as the previous run). Formula says 427.5rwhp. Hmmm! SO I lose almost 8hp but the car goes 1.2mph faster? Yes, lousy 60' gave me more time on the track to build boost and mph. Given an extra .31secs on the top-end with that kind of HP and you will definitely have a higher top-speed. Lets play around with the formula and show how ET and MPH is affected by HP and vice-versa. We have a 2800lb turboZ that went 12.0 @ 115, generating 339.1rwhp. If the HP and weight was unchanged but the ET was quicker at 11.85, the formula says the mph would be 114.3. If the 60' was lousy and the ET went up to 12.15, the mph from the formula would be 115.7. Exact science, absolutely not, but it proves my point and my experience everytime. Here is another strange one I experienced. I ran against a 600hp SupraTT. He bobbled badly at the line and had a 2.6 60' and an ET of 12.76 but almost 129mph!! He just had a bad start that gave him more time to build boost and an extra second on the top-end with that HP is going to make a huge difference in MPH. For those with a passing interest, I probably rambled and the non-turbo guys are probably not convinced

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Tom, I am a firm believer in getting the most of the turbo you have before jumping to a bigger one and you are not close to the full potential of your current setup. As a point of reference, I was close to 300rwhp @ 17psi with a stock L28ET engine, SDS, SVO 36# injs, 300ZX 55mm TB, NPR, my DP and 3" exhaust. Very similar setups but you have a better I/C and turbo and I had a better exhaust system, the 3 things that are going to make your HP. That said, you should come close to matching me. My formula says 235rwhp with your ET/MPH/weight and 291rwhp for mine. Even if we want to be conservative, I would say there is another 40rwhp to be gained simply from tuning. It is quite unbelievabe the HP difference in a turbo engine not properly tuned. I have seen 60hp difference in one night from my 1st run to my last because something was off or I kept tweaking the fuel management. If it is just a matter of tuning or there is a real problem why you are not making more HP, a bigger turbo will make more HP but only mask a problem. BTW, given the same HP, a better 60' would give you a quicker ET but you would have a slower trapspeed. No matter, the ET is what counts unless you are just looking to see how much HP you are generating.

Not sure if you can really quantify it. Just remember that heat is a turbo's worst enemy and high underhood temps will kill any hybridZ. For a turbo car I recommend the exhaust manifold, underside of the manifold heat shield, the turbine housing and the downpipe. That'$ going to add up. On the other hand, consider spending a lot of dough for a good I/C only the have the I/C to TB pipe getting very hot and the bottom of the intake almost glowing . Kind of defeats the purpose. Nissan put that ugly fan by the fuel rail for a purpose. It gets hot under the hood! Worse case you end up pouring unnecessary $$$ into making the cooling system more efficient.

I suggest you post this question on the 2 Turbo Buick boards in their tramsmission forums. Lots of tranny vendors and experts on those boards with a specialty in the 200. www.turbobuicks.com www.turbobuick.com

the best answer will come from the SDS vendor but since the SDS only uses the O2 if you choose to tune in the closed loop mode, it really would be 2 seperate devices. I wish I could get a straight answer, not guesses, on the life of a WB O2 sensor when used with racing fuel with a very high lead content. It would get very expensive if I had to change those puppies out often.

Scott, if you are running rich in all operating ranges, then the 2 most obvious, especially with swaps like yours, are: some missing or malfunctioning temp sensor that has the ECM believeing that the engine is not up to normal operating temperature or fuel pressure too high because of a malfunctioning or incorrectly set FPR. It is a common mistake to set the FP with the vacuum line connected. FP should be set in the no vac/no boost condition.

There is nothing wrong with a little spike, especially if it is immediately as you romp on the throttle. E.g., boost is set for 10psi and it quickly spikes to 12psi when you hit the throttle but immediately comes back to 10psi. The concern, of course is the fuel is set to support 10psi not 12psi. At that point, the engine is not under a tremendous load and the concern should be 12psi at WOT in a high gear where the engine is under the most load. This usually results from "creep" as that fine article points out. As for making the wastegate hole larger, IMO really not necessary untill you are moving so much air and cannot bypass the turbine wheel quick enough to match the rod actuation. The hole in my turbo is "stock" size and I have a little initial spike, but nothing to worry about. If you end up doing it, be certain to check how much room you have outside the marked circle on the face of the puck. You might have to go to a larger diameter puck.

Forced Induction? How much HP? Slicks? How quick you looking to go?

Rick, I would not be too quick to jump to a .82 and you can go a long way with that turbo. IMHO, do not upgrade your turbo until you have maxed it out. I hear one of my buddies snickering . properly tuned, you can push 350hp with that turbo and an efficient I/C. Not quite sure I understand exactly what the problem is or what you are trying to say in the quoted statement. With the actuator set as described above, the boost will be limited to the rated spring pressure which sounds like it is 10#. Shortening the rod preloads the spring and increases boost. If you are experiencing spikes with this simple setup, then try various id lines and see if that makes a difference. Also look for things that would prevent the wastegate puck from fully opening (the root cause of boost spikes). Possible causes are a torn diapragm in the cannister (blow into it and listen for a leak) or something in the housing preventing the puck from opening like bent shaft, bad bushing, etc. Disconnect the rod and move the lever by hand several times feeling for smooth action. Any little hitch or resistance could be exacerbated by the spring pressure.

Brad, I probably have some confusion interpreting what you are saying and if so I apologize. I do not know what a "compressor bypass valve" is, but your description of it is indeed that of a BOV, except for the part about routing it back in front of the compressor. A BOV can vent back into the itake system or the atmosphere depending on the application.

They introduced it on the C4 IRS in '84 and I considered using it, but the C4's is a massive aluminum unit shaped like a u-channel and about 10" tall at the diff and narrowing down towards the tranny end. It is a work of art but just no room in the tunnel and it required extensive mods to the tranny tailhousing since the TH2004R does not have the mount points. It would also have interfered with the driveshaft hoop and tranny x-member.

Its called a Hybrid! Yea, yea, make fun of my baby turbo, but it is enough to whip ya, at least in a brag race anyway. and more than enough to get me in the 10s with room to spare . No need no stinking twin turbo. One of these days 2 folks on these forums are actually going to race each other. Andy, Scotty? BTW, you did a masterful job on the machining and came up with ingenious ways to get it done, but refer to the post below, dated 5/20. http://www.hybridz.org/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=6;t=001343