Pyro

check out this site. http://www.ryanscarpage.50megs.com/combos1.html combo 77. crane 260 cam is another good choice. 204/216, 0.427"/0.454". made 323hp at 5000 and 390 ftlbs at 3500 with a 355, 9:1 cr, and dart sr heads. There is a perfromer cam test with edelbrock heads on this site, 8.5:1 cr 350, shorty headers, q jet, made 310hp. But 9.5:1 cr will add about 5% more hp (325hp).

With no stall and 9.5:1 cr. I would use a simple Edelbrock performer cam with a performer intake and a q-jet. The cam has 204/214 duration with 0.420"/0.442" lift. Should make about 325hp with a set of vortec heads. Set total mechanical advance timing at 35 degrees. More exhaust duration really helps out the vortec head. I would also spend a little time cleaning of the sharp edges under the exhaust valves. Pull out the exhaust valves and smooth the transition between the port and the valve seat. Could be worth another 10 or 15hp. Q-jets are great carbs as long as they are in good shape and not rebuilt by autozone. Cliff's performance carb shop is a good place to send your carb. With a stock converter I would not go over 208 degrees on the intake and use another 10 degrees for vortec heads (poor flowing exhaust ports).

I have have experience with the the combos you described. flat top l28 with p79. good off boost response but had detonation problems over 8 psi and only could take 15 to 17 degrees of total timing while on boost. Much faster than a stock non-turbo. worth the install. dished pistons with P79. a little sluggish off boost but with a stock turbo boost comes on quickly. ran good with 12 to 14 psi of boost but tended to detonate after that. could run about 20-22 degrees of total timing. Much much faster than the flat top low boost engine. dished pistons and p90 head. Also a little sluggish off boost but with a stock turbo boost comes on quickly. Ran good with 15 psi of boost (about max for a stock turbo). Could run 24-26 degrees of total timing. Hard to hear detonation with this combo but you could feel it in the engine. A little faster than the P79/dished combo due to more timing. Cork bell's book would recommend using the lower compression ratio. All these combos were used with the stock ecu and fmu's for fuel enrichment. The mechanical advance were either locked out or reduced. I'm sure much better results would be had with an aftermarket efi system with ignition timing control.

I have a story for you. A friend on mine bought an AutoZone 350 short block. Then he installed a CompCam 292H (244/244 at 0.050), sportsman II's heads, victor JR intake, 750 Holley, and a 275hp shot of n20. He put his engine into an 3500 pound 1980 Camaro with a LSD 4.56 gear and 8 inch 4000 stall converter. He raced that thing every weekend and street raced it during the week. He used 20 pounds of N20 every week for over 2 years! That is over 2000 pounds on N02 through an AutoZone short block using 275HP at a time. Plus shifting at 6500 rpms! And he drove it to work everyday. The bearings finally got hammered out but it took a long time and a lot of full throttle runs. If the n20 is set up right, your engine will last a long long time. Run the proper fuel, ignition timing, and the right n20/fuel mixture and a 200 or 250hp shot is no big deal for a 350. I ran a 275hp shot for a few years with no issues using a 2 bolt main block and hyper pistons.

1.6 ratio rockers on the stock cam can pick up 30hp.

81's seem like a lot of jet. I use 70's on my 750 vaccum secondary (3310) with a 244/244 at 0.050" cam. runs mid 11's at 120 and mid 10's at 135 with n20. Your ignition timing is low. And low timing will make it over heat. Try another 5 or 6 degrees.

I think your timing is just right. Long duration cams need more timing at idle or else the exhaust will glow orange. They also need lower a/f ratios at idle because of the added over lap. FYI, stock turbo timing is 24 degrees. It is real hard to change the LSA on a regrind cam. However, the extra thick pads (0.230) for a 290/280 cam does indicate something to the lsa was done. Your new cam is very big for a street turbo and does not have nearly enough LSA (112). A cam that big needs around 118 or 120 LSA. You could easily run 8.3:1 cr with that long duration. The amount of vacuum drop at idle with your new cam seems about right to me. A turbo with a lot of valve over lap makes a very narrow power band. A use a MSA stage 1 turbo cam 260/250 with 114 LSA, and it pulls hard to 6500 rpms. Boost starts at 3000 rpm (5 psi) and hit full boost by 3500 but I think the lag is mainly due to a free flowing hot side. Maybe a stage 2 from MSA is what you need.

It mostly depends on the cam in the engine on how much power will be lost with exhaust manifolds. A cam with 240 degrees duration at 0.050" could lose 50hp with a set of stock manifolds versus full length headers. A set of shorty block huggers will be down 25hp as compared to a set of full length headers. However, if the engine has a mild cam in it, the losses may only be 20 to 25 hp with manifolds versus full length headers and only a 10hp loss with block huggers. Block huggers are a nice compromise.

No problems with the steering rod. I'm using a t04B-h3 compressor and also did the same with a stock T3 turbo. However, not sure how a t04e with a spacer would fit. Looks like both ways work. The point is to make use of all the space under the engine.

I would not recommend getting a turbo on e-bay. You really should spend the money and get the right turbo for your car. The flow of the exhaust turbine will effect the spool up time and as long as the compressor is not in the surge zone it will make boost. To get what you want, "no lag and 320 to 340 whp you will need the right turbo. Not a e-bay turbo that looks like it will work. Get a stock turbo from a 280zxt and have the compressor changed to a T04E-50 trim at a turbo shop like Majestic Turbos in Dallas. Don't mess with the exhaust turbine unless you are going to change the cam. FYI, a stage 3 exhaust turbine mod on a T3 turbine makes full boost around 3500 rpm which doesn't work well with the stock cam.

Don't worry some much on the torque rating of the trans. 450 ftlbs rating will be enough. Tire spin will act as a circuit breaker. I ran over 600 ftlbs (n20 feed sbc) into a T5 which is only rated for 300 ftlbs Just don't power shift it or do high rpm clutch drops.

What size solid roller cam did you use? how do those solid rollers sound? How often do you adjust and what size lash? I went with hyd roller lifters on my 454 but those make the float problem even worst. however, they cured the flat lobe issues. A flat tapent BBC cam of the same duration of a SBC typically has more lift which causes more cam issues because the lifters are the same diameter. Then there is the new formulated engine oil which also eats lobes.

I didn't mean only drag racing. however while we are on the subject, much hard to hook up a BBC in a stock bodied Z car than a SBC. No, I don't believe everything I read. Thanks for asking. I have my own set of valve floating cam eating big blocks for that (no reading required). However, my experiences seems to match the published BBC tech articles. And I also have a 7200 rpm sbc with just a stock set of dart 200cc heads and a compcam 292H. Hyper pistons, 2 bolt block, and a factory steel crank. Needs a rebuild now but lived for 8 years with red line drives every time I got in the car. So, I disagree than a sbc needs more that a flat tappent cam and good valve springs to live. Chevy high performance used a little 5.7 ls1 engine with a set of 210rhs heads and a tiny xr265hr (212/218 with 0.520") and made 529hp and 488 ftlbs. There are many other examples of the 5.7 making over 500 with bigger cams and ported stock heads. The 6.0 are getting closer to 600hp with heads and cams. Real world performance. Check out some LS1 sites and notice the carb guys a more often than not beating the efi guys on the drags.

general run is... light car does better with a small block heavy car does better with a big block Takes a lot of work on the valve train to get a bbc to rev. Their valve trains are very heavy and takes lot of spring pressure which quickly wears out cams, rockers, lifters, and valve guides. Takes a lot of expensive parts to ligthen the valve train on a BBC. A SBC can easily rev to 7000 rpm with a stout flat tappet cam with a moderate amount of spring pressure. A LS1 with some head work and a moderatly sized cam can easily make 500hp. Does even better with a intake and carb.

I broke more outer axles than R200 diffs or halfshafts with my 240. But I was using MT drag slicks and 5000 rpm clutch drops. Once the car started running 10's at over 134 mph and 1.5's 60 ft is when the stock axles, halfshafts, and diffs started to break with frequency. I didn't have too many problems with the rear end running mid 11's at 120 (no N20) but 10's crossed the line (with N20). 425 to 450hp, 11:1 cr. 362 sbc, 200cc dart iron eagles, plus a 175-200 hp shot N20. Car uses a GMT5 with 3.90 R200. I quit racing it because I got tried of replacing stock parts and decided I wanted to live a little longer. So, I going for a 4 link with a straight axle before I race it like that again. Or just detune it and enjoy it on the street.

For less than 400.00 you can turbo charge your current engine over a weekend. Go to your local "You-Pull-It" junk yard and get the following stuff. 280zxt exhaust manifold: 25.00 280zxt turbo with wastegate and downpipe: 50.00 280zxt oil line to turbo and J-pipe: 15.00 280zxt oil pan and oil pump pick up tube: 25.00 new stuff or used off e-bay Bell engineering FMU: 225.00 new, 100.00 used Connect exhaust: 50.00 Other things to do: 1) silicone up the advance slots in the distributor and set timing to 20 degrees. 2) Set fuel pressure on the FMU to 55-60 psi at 7 psi of boost. Will allow your stock 78 to run a mid 14 second 1/4 mile at 96 to 98 mph. Add mega squirt, stock 280zxt injectors, P90 head, an intercooler, and turn the boost up to 15 psi and turn some mid 12's at 110 mph. All with the stock turbo, which BTW, makes a fun street turbo due to no lag. upgarde the stock cam and add a t04e-50 trim and run some 11's. However, you will need a better clutch. A SPEC stage 1 or 2, 240mm for a 2+2 Z will do fine (nipponpower.com)

The pressure depends on the amount of vacuum. High vacuum causes low pressure due to a vacuum sensitive FPR My car idles at 26 psi and drops to 22 during deceleration. 36 to 38 psi at WOT (zero vacuum). You can unplug the vacuum hose from the fuel pressure regulator to simulate WOT.

My engine will not start with out the cold start injector.

no spacers will not help. That only increases the maximum pressure and will have no effect until that pressure is reached. A turbo oil pump has longer rotors so it pumps more oil per revolution. This helps low pressure at idle try using thicker oil. like 20w50. This also helps low pressure at idle.

I see, no n20 off the line. That makes since. Sounds like you have a good setup. But, I think you could use a little more cr and a little bigger set of heads. Maybe 11:1 cr and 195 afr's or maybe get some 210 afr's which would also work well on your future 406. I think you are at the limit for 170cc heads with trap speeds in the low 120's with 2750 pounds.

What heads are you using? What compression ratio? What carb and intake? What mufflers? With 131 mph and 2750 lbs that comes out to about 485hp. And that is with 180 shot of n20. So your engine is only making around 340 hp (410 crank hp). Seems a little low for a cam that big. what mph on the motor? 117, 118 mph?

Installed a Dana 36 LSD (from a 80 vette) in a 77 280 Z. Took some work to modify the stock 1/2 shafts and to install mounting studs in the vette diff cover, but it works great.

Yes, the turbo output OD is 2 inches but the wall is about 1/4 inch thick. So, all that air flowing out of a 1.5 inch hole. Makes me wonder how big a pipe is really required.

The BOV vents into the suction side of the turbo. I'm still running the stock efi so didn't what to vent to atmosphere and lose metered air. Doesn't make the "cool" turbo BOV sounds but that is OK with me. I ran a J-pipe for awhile and then later added the ic. I didn't notice any difference in lag and only measured a 1 psi pressure drop which I think is typical of any ic install. Just moved the boost reference to the manifold to solve the pressure drop issue.

Good choice! That is the way I did it. Also did it that way on 2 other Z's. Doesn't effect the response of the turbo in anyway. However, I did run my pipe between the engine mount and alternator. And my engine is not quite as clean as yours. hahaha