Pyro

I had the same problem. Didn't think sound proofing would be enough to fix it. So, after the transmission I put in a short H-pipe, then two short dynomax bullets before the Y-pipe then to a 16 inch x 5.5 inch case dynomax super turbo. This completely fixed the drone and made the engine very quiet. With only the dynomax on the end, the car was undriveable due to a very very loud drone.

Yes, that is true. 2-1/4 has more surface area to cross section than 3 inch, thus making it not as efficient. However, most exhaust theory articles will say dual 2-1/4's are equal to one 3 inch. The theory is 2-1/4 is good for 200 crank hp and 3 inch is good for 400 crank hp. dual 2-1/4 have cross sectional area of 7.09 square inches. a single 3 inch has 6.5 square inches. the dual 2-1/4's have more friction but the extra area makes up for it.

yes, the bullets before the y-pipe. My final build was this.......I ran 2-1/2 pipes off the block huggers headers, then put in a short H-pipe right after the trans, then dual 12 inch bullets, then to the Y-pipe (dual 2-1/2 to single 3 inch), then to 2 mandrel bent 90's and the large case turbo muffler on the end. If I was going to do it over, then I would use 2-1/4 pipe off the headers instead of the 2-1/2 pipe. As two 2-1/4's are already bigger in cross sectional area as one 3 inch pipe, making two 2-1/2's over kill and a harder fit under a z.

The standard turbo muffler and most commonly sold uses a 14 x 4.5 inch oval case. The next bigger size is 16 x 5.5 which is quite a bit bigger and barely fits in the stock z muffler location. a bigger case will flow better. try it get the biggest case that you can. you should use a offset outlet because it hides the muffler better. I did a single V8 (350 chevy) exhaust system on a friends Z. The bigger case sounded much better than the smaller case. Furthermore, you should really plan to install two dynomax bullets up front along with the dynomax turbo in the rear. When I first did the exhaust it sounded terrible with only one muffler in the rear. The drone was unbearable in the car and the exhaust outside also sounded terrible in a weird way. The twin bullets fixed it. Now it makes a nice deep quiet idle, quiet while driving slow, and impressive sounding when on the throttle. hard to believe but the bullets up front made a "night and day" difference.

http://www.summitracing.com/search/Part-Type/Mufflers/Brand/Dynomax-Performance/Universal/Yes/Case-Shape/Oval/Inlet-Diameter-in/3-000-in/Outlet-Diameter-in/3-000-in/Outlet-Quantity/Single/Internal-Construction/Turbo-style/Outlet-Location/Offset/?keyword=muffler dynomax sells at least 4 mufflers with 3 inch pipe with an offset outlet. 17770 (20 inch case) 17789 (30 inch case) 17743 (14 inch case) 17792 (16 inch case) you most likely have the 14 inch case. the 16 fits with some trimming.

For the collector, use the dark grey gaskets that autozone sells. They have a metal wire core. at the head/header interface, use felpros for stock applications. little metal gaskets that fit each port.

I have seen that (just bigger ends). You need to pay attention to the muffler case size. They typically give the measurements. I fit a larger case 3 inch dynomax turbo into a first gen but it is tight. Had to cut the input end off close to the case to fit it in. then welded the short 90 mandrel bends right up to the muffler. The bigger case muffler sounded better than the regular sized case and made noticeable more power (spun the tires easier at lower rpm).

That cam would work well with a 4 bbl intake and holley. Your manual trans is a plus for that cam (no stock converter). I would use a more mild efi cam from compcams. Like 206 to 212 on the intake at 0.050" and 6 to 10 degrees more on the the exhaust (compared to the intake) then use 114 LSA with efi. If you really want to make more power, then swap over to vortec heads and intake. Should pick up 50hp with that swap. Then maybe another 30 or 40 with a mild cam and exhaust swap. 300hp is with in reach.

The cheapest way to add a little power is with more cam, more gears, and more compression. What is your current setup? flat tops (81 to 83 engine) or dished pistons (75 to 80)? what cylinder head do you have? And easy way to go up in cam size is to send your old cam for a regrind and get the rockers resurfaced. If you stay at 260 degrees (212 at 0.050") and around 0.430" lift then you can use the stock springs and retainers and use stock compression and gears. A regrind this size typically requires 0.160" thick lash pads to correct the valve train geometry. DeltaCam does cam regrinds for 60.00 and rockerarm resurface for 4.00/each. Courtesy nissan sells thicker lash pads for 3.00/each. So for 144.00 plus 20.00 in shipping you can add maybe 15 to 20hp.

adding a turbo is an easy way to make power.

Cam, compression, and gear ratio should all match. If you want a fast drag car with good top end then use 10:1 cr, a cam in the 290 degree range, proper springs and lash pads, and a 3.90 to 4.11 gear. To get 10:1 cr use flat top pistons and a N42 or N47 head. If you have a 8.3:1 cr L28 (1975 to 1980 engine) then it will not take much cam. A stage 1 MSA cam would be about the max you should use. It will help but not that much by itself. A change to 3.90 will help if you are using a 3.55.

years ago.... when did my first v8 conversion (350 chevy with a T5 trans), I used 2-1/4 duals off block huggers then to a 2-1/2 single (crushed bent) then ending with a turbo style muffler. Back then my 240 ran high 12's at 110mph. If you go by pipe ID area then 3 inch (6.488 square inches) is about equal to two 2-1/4 pipes (7.08 square inches). So just run dual 2-1/4 pipes to a 3 inch single but make sure to use mandrel bent pipe at the rear. I doubt you will loose much hp with a single 3. Especially if you use a high flow muffler and mandrel bend pipes in the rear. I built a system like this on a friends V8 conversion and it had huge resonances/droning issues. I ended up adding a H-pipe after the transmissions and installing 2 dynomax bullets in the dual section of the exhaust (right before the Y-pipe). Really made a big difference. Car went from undriveable to sounding almost stock when driving slow.

you are opening a can of worms with a V8 conversion. Getting the engine and trans is the easiest part. if you don't have the money for a transmission then you will not have enough to do a good swap. And your car will sit for years then end up being towed to the junk yard. If you are short on money then you would be better off just adding a turbo to your current datsun engine. Your first V8 conversion always takes much longer than you think and cost much more than you plan for.

here is a grainy photo of the front mounted afm and top view of ic pipe.

I ran my IC pipe under the pan over 5 years ago. But ran the tube up between the engine mount and alternator.

just told you. cut the wires and extend them to mount the afm in front of the IC. works great. I have relocated 3 afm like that.

Run the afm out in front of the radiator. just cut and extend the wires to the afm.

not a bad cam for stock heads. But needs more than stock compression and more gear and more converter to make any power. they add a lot of exhaust duration and a narrow lobe center angle to make a rough idle and to close the intake sooner. This works well with stock poor flowing heads. I would use 9 to 9.5:1 cr (not stock 8:1) 3.55 to 3.73 gears 2500 stall headers with 2.5 inch pipe and a set of dynomax super turbos. if you don't plan to change the compression, gears, and stall then install a smaller cam. a cam the size of a compcam 252H (252/252, 206/206 at 0.050) would be a good match for a stock 350 and driveline. lastly, use zddp oil additive with your new cam. (http://www.zddplus.com)

maybe he is talking dual 2.5 inch on a V8.

sure, I would be glad to help. I have done this on multiple z cars. makes a very nice improvement over stock for very little money. with the right fuel pump, compression ratio, and intercooler, you can run as high as 14 psi using all the NA injection system with a fmu for fuel enrichment. Megasquirt with bigger injector works better but that fmu is so simple.

skunk if your 77 engine is in good shape then just install a stock turbo setup (exhaust manifold, turbo, wastegate, downpipe, j-pipe, oil pan, oil drain line, and oil feed line). then lock out the ignition advance and use a bell engineering fmu set to 55 to 60 psi of fuel pressure at 7 psi of boost (stock boost). makes a simple and cheap turbo setup. good for mid to high 14 second 1/4 mile et's at 90 to 95 mph. Later add a megasquirt efi system, bigger injectors, more boost, intercooler, and a stronger clutch.

depends a lot on cam timing events and ignition timing control. what cam are you using? and does your efi system have ignition timing control?

I hate those edelbrock carbs! get a holley! what is the ignition timing setup? (initial, total mechanical, how much vacuum advance, ported or manifold vacuum advance) stock cam?

nipponpower.com check out the SPEC 240mm stage 1 or 2 clutches. the stage 2 requires a 200 to 300 mile break in.

I run the msa turbo stage 1 cam with 7.4:1 cr and a T3 stage 5 turbine with a T04B-H3 compressor. Starts to build boost at 3000 and makes full boost by 3500 and pulls hard to 6500. Drives nice on the highway as I can drive it at 80mph without boosting (10 inhg vacuum). The stock turbine was running at 0 inhg at 80 mph (almost boosting). Plus the bigger turbine hits much softer which makes it more controllable, unlike the stock turbine which is on or off. My compressor would surge if boost was made any sooner. Not the best compressor but it fits without a spacer. The t04E-50 is the way to go but requires a 1/2 inch spacer between the turbine and manifold. Yes, Brad is correct. match the cam to the turbine. a stock cam runs nicely with the stock turbine. A bigger cam does well with a free flow turbine. It is all about cam overlap (reversion) and pressure difference between the intake and exhaust manifold. Small turbines create lots of exhaust manifold pressure which doesn't tolerate any valve overlap. Great for low rpm torque.