Best way to get 15-25 HP in SU 2000?

[GoldHawg]

All--
Looking for your best ideas at the easiest ways to get add'l HP out of the stock 2000, in easiest/cheapest order. how hard is it to get 15-25 more HP, assuming I want it very streetable.

Thx for any thoughts you have.

[spl310]

Put on a free flowing exhaust and install the B cam and you should be happy.

[GoldHawg]

Wow. that sounds pretty easy. So what next after that? Are there any ignition upgrades that make sense? Also, since I'm a newbie to this site, what is the "b" cam, where does one buy it? Are there any other valvetrain upgrades while you are changing the cam?

Thx!!

[spl310]

Let me ask a stupid question. Have you actually driven your car at this point?

The cam was available from Nissan. Not sure if they still have any. The vendors all probably have them though. It is the "Solex" cam and is a bit of a hotter grind. You can get yours reground as well to give more umph. For the distributor, there are several electronic ignition conversions. The Gary Boone gets rave reviews, and the Pertronix is favored by some. Crane also made one to fit the Hitachi distributor. Some folks have gone crank trigger.

It all depends on a few factors. How much money you want to spend, how much skill you have in doing engine modifications, how much of a compromise you want for a street car.

[keith0alan]

Pretty straight forward. B cam, electronic ignition, free flowing exhaust, proper needles in the SUs. Once you get to the point of sorting the SUs post a note and I'll help out.

You should either be able to find a reground B spec cam or even something hotter from our venders. The advantage to the B cam is no other valve train mods are required. Just don't forget, replace the cam and followers as a set.

keithw

[spyder]

Tweek of the distro curve can also help. IIRC, the earlier models had more initial advance but less overall advance. THis will help in low end grunt. I used a pertronix electronic ignition in place of the points for many years. I liked the way it would keep the advance retarded until the engine would rev past 400 rpm. Made it easy on the starter. I have heard others state they don't like it but it worked fine for me.

[SLOroadster]

Hog out the intake, match the ports to the head. A high flow ceramic coated header will also help. The biggest hang up with the U20 is the exhaust side of the head. The ports don't flow what they can (about 110 cfm). A cam with a slightly longer exhaust lift and duration will help some as well. Isky can regrind a good one. As for the exhaust system, run the biggest set of headers you can find, 1 5/8 primarys will do the trick. Run those into a 2 inch pipe, and run the most open exhaust you can find. I run a straight pipe into a Borla XR-1 muffler. Its a bit on the loud side for most people. While you're at it, a light weight flywheel will help as well.

Will

[RC240z]

A better question is where are you looking for power? More torque or more HP? Exhaust modifications like what has been recomended above will make more power on the top end, too large of an exhaust system will hurt your low end torque until you get into the powerband where you will benifit from the above modifications.

What are you doing with the car? Daily driver, weekend play car? occasional auto-x?

Another solution would be a better set of rear end gears. A 4.11 or 4.37 gearset will be much quicker off the line than the stock 3.9 and give you better accelleration with the same HP, for what you would spend for a new "B" cam installation and header solution. Limitation to the lower gears is your top speed would be limited to about 110MPH.

No matter what you do it will be a trade off. Think about where you want to pick up more power and then go from there.

A little food for thought.

[dbrick]

Is the 2000 a 3.90 rear I thought it was a 3.70.

Everyone brings up a similar point, drive the car, see at what point in the speed/RPM range you WANT more power, and then put it there. If you want more lowend grunt, I would think a B cam would make it worse, whereas the rear end gear change would make a world of difference. If you want top speed, then it is the opposite.

Also, what year is the 2000, does it have a smog distributor, air pump still attached and smog needles?

[spl310]

The 2000s came with the 3.7. The 1600 with the 3.9 and a 4.11 listed as optional.

[mgslayer]

When I got my beast I was obsessed w/ getting the solex set up ( Carbs & Cam). Then I looked at my funds or lack there of and reality took hold. This is a few years back, not sure what they are going for now but I put a 4.11 ring and pinion from Rallye in for about 1/3 - 1/2 the cost of the solex set up. No real before and after times, but definately a bigger grin off the line after. It all depends what you want, what your abilities are and what you are comfortable with undertaking. Definately enough knowledge from folks here that can probably walk you through almost anything. An exhaust shop can do the 2" exhaust, replacing the cam is not that difficult IF you don't let yourself get psyched out by having to remove alot, and put it back together. Even a header is really just an unbolt and bolt on operation. (This one usually requires the help of some small hands, penetrating oil, etc.) When all is said and done it's your ride. If you're not in a rush and it's running well, enjoy it for a while as you sort out your options.

Happy Wrenching
Mark

[Howard R]

The average 0 to 60 times(135 hp) in most of the car mags of the 60's, is approximately 10.2 seconds. I've seen as low as 9.6, and as high as 10.6. These times are with 3.7 gearing. Theoretically, what do you think the 0 to 60 times would be with 3.9 and 4.11 gearing? Most of us will never drive our cars at the top speed of 123 mph (Victor might be the exception). So lowering the top speed and have more grunt in the lower end, might not be a bad trade-off. Any opinions?

[Victor_laury]

Since the 4.38 swap, the heedy days of 126 mph are long past. Now 115 is my fastest recorded (just over 6,000 rpm). It'll go faster, I just can bear push it up any further. Funny, as I often exced 6,500 as a shift point.

It is an effective gain in performance.. You don't see me swapping back the 3.7 do you?

[GoldHawg]

Thx for all your comments. To the ??s, no its not a stupid one, I do NOT own the car. I drove a 1600 for several years, and its currently parked in a barn. I have an opportunity to pick up a 2000 that has been sitting for many years, but it has all the pieces. I am intrigued by the EFI swaps that are in the other forum, as I enjoy my LT1/6speed combo in my 71 Cutlass conv. But these swaps seem a bit harder in a roadster, and the power in a stock 2000 is pretty good. I am trying to decide if I could be happy w/a pretty peppy carburated 2000, or just go EFI. Lots of decisions, so just in the info gathering mode now. I am hopeful that w/Ztherapy carbs I could get a pretty streetable well tuned car, w/o fuel injection.

[spl310]

I do NOT own the car. I have an opportunity to pick up a 2000 that has been sitting for many years, but it has all the pieces.

Well, that changes the picture. Remember that the 1600 is rated at 96hp while the SU 2000 is rated at 135hp. (I am not trying to start a debate as to if those number are real - just using them for illustration purposes), so you are looking at a healthy jump in power. My suggestion (pretty much the same suggestion that I give to most Roadster owners) is to get the car driving by fixing what it needs to be a driver, and then enjoy it for a while - a few months at a minimum. THEN assess what you really want the car to do and go from there.

Now, if you want to build a go fast car with EFI and all that fun stuff, here is a thought. Get the 2000 and make it a driver, then leave it alone. Find a forklift store and pick up the crank for an H20. Rebuild the R engine out of the 1600 as a stroker. Since you like EFI, there are companies that make SU throttle bodies for EFI conversions. The nice thing about modifying the 1600 is that parts are MUCH cheaper than the 2000 parts. Plus, you can sell the 2000 later and make a little profit to roll back into the 1600.

Since you have the 1600 in the barn, you have a good parts source should you decide you want to make the 2000 a stormer. The diff swap is easy enough and gives you more dig off of the line.