bolt-on performance for a '79?

[Slartibartfaster]

Newbie here trying to make considered decisions... I'm buying a 79 non-California spider that is totally stock and totally original. I want to make some relatively easy and reversible mods to improve throttle response and power without changing the head or cams.
My questions are what should I realistically expect to gain by replacing just the carb and exhaust?
Is there a big driveability bump with electronic ignition??
What should I prioritize?
And, what is the low hanging fruit when it comes to handling improvements? I kind of like the relatively skinny tires... Fun to throw around but want to keep it balanced if I'm adding a bit of power.

[bobplyler]

Just the carb will make a significant difference.

[AndyVAS]

79 should already have electronic ignition.

Swap the intake manifold and carb. Either go with the 1800 manifold and aftermarket carb or go big time with twin carbs.

Put on a header and full exhaust.

Do a good tune-up with all the normal stuff and a new ignition coil.

For easy suspension mods, put in a set of performance springs and new shocks. Our springs and hydraulic are a good pairing. If you're up for a little work, put in polyurethane bushings.

[klweimer]

I agree with the ideas above. I would look at the condition of the catalytic converter. The originals were pretty low flow. If you don't have to do smog testing, you can replace with a "test pipe", if you need to keep a cat, I'd go with a magna flow. Lots of guys find a local shop that can build a custom system with about 2" dia pipe.

I would probably start with a good check of the brakes and replacement of all the rubber fuel lines.

Kirk

[joelittel]

There have been a few owners who stated that a lightened flywheel was the best bang for their performance buck. Especially when considering throttle response.

Is that mod reversible? Yes. Likelihood of you actually taking it out and putting the stock one back in..... slim to none.

[RRoller123]

There have been a few owners who stated that a lightened flywheel was the best bang for their performance buck. Especially when considering throttle response.

Is that mod reversible? Yes. Likelihood of you actually taking it out and putting the stock one back in..... slim to none.

+1. Tremendous improvement in acceleration.

[TX82FIAT]

Good comments with carb, flywheel, exhaust, tune, 1800 head and other suggestions. I've always thought of the 79 as a dog because of the emissions gear that came stock. There are a lot of threads on getting rid of this performance robbing system. If permissible where you live on a 38 year old car, consider a retrofit with an earlier intake manifold and carburetor as suggested. Verify your CAT is not restricted. The retrofit is relatively simple to do on your own and will produce substantial change in your 79. I know I'll take heat for this... But, having had a 79 in stock form, owning an 83 and an 82 as well as driving the earlier spiders models. The 79 in stock is my least favorite spider. BUT... It has a ton of potential.

[Slartibartfaster]

Wow - thanks everyone for your help. I've been shopping for quite a while and was avoiding the 75-79s because of the low power/emissions issue. I'm buying this 79 though because of the truly impressive condition and care it has received from it's single owner. As they say, when buying an old car, buy the best one you can find. That's why I'm concerned that any changes are reversible; I think it could be a show winner and I don't want to screw up it's future value. There are plenty of Spiders that are right for restomods and I'd love to build one just they way I want it in the future; but that's not this car.

While not fast, it runs beautifully now and is tight as a drum. I think the carb/manifold step will be first followed by a lightweight flywheel...probably winter projects while the car is put away.

Now...which carb? They're all a bunch of numbers to me. I want to keep it simple and reasonable, so dual carbs are probably not for me.

I'd also love to pull in the front bumper (plan to keep the tube monsters for now)...does anyone sell shorter mounting shocks?

[TX82FIAT]

I have not seen shorter tubes for the bumpers. However, I have seen folks drill a hole in the tube to release the oil in the shock and then push bumper in and drill another hole. You line up the holes on the smaller and larger circumference tubes inserting a bolt through the holes to keep the bumper tightly tucked in. These big bumpers are not real effective anyway so a black bolt and nut on a tight tucked bumper will not really hurt the impact protection much. Use a little sealant to help prohibit rust in a very rust prone area where you drill.

[nelsonj]

If it's a stock 79, I second everyone that said a new carb and intake manifold. I have a 32/36 DFEV (as I recall) Weber and I like it a lot. Pretty much anything will be an upgrade from the stock 79 carb.

Then replace the header/down pipe with a 4-2-1.

I plan on a lightened flywheel next time I change the clutch.

Peace.
Out.

[bobplyler]

Then replace the header/down pipe with a 4-2-1..

The 79 comes with a 4-2-1

[scrapironchef]

Then replace the header/down pipe with a 4-2-1..

The 79 comes with a 4-2-1

Non CA cars mostly had the 4-2-1 but californicated models had the 4-1 that is widely despised. I've seen quite a few scattered avout the rest of the country so I wouldn't bet that they didn't end up on non CA builds towards the end of carbed production. That may be from cars migrating though as our cars last longer than the ones in the salty states.

[lglade]

If the car is *all* original, then the rubber bits are nearly forty years old. Be sure to inspect the fuel hoses/brake hoses and make sure the car stops and steers correctly before seeking to improve performance. If your car smells like gas, then plan to take a weekend and replace the rubber hoses in the engine compartment and those going to the tank. Nothing sucks worse with a old car than being broken down or heaven forbid having an engine fire.

[baltobernie]

I think the carb/manifold step will be first followed by a lightweight flywheel...probably winter projects while the car is put away.

I would not replace or lighten the flywheel without planning on replacing the clutch assembly while you're in there. Frankly, I didn't notice that much of a difference with the lighter flywheel.

INow...which carb?

32/36 DVEF on a sinlge-plane manifold. A good exhaust system is a better performance value than a lightened flywheel. Valve adjustment, good plug wires and validate distributor advance and output. All of these items combined will result in a very noticeable improvement.

[joelittel]

+1 on the rubber bits. Do this first. Then get it running in perfect stock spec, and then modify the areas you'd like to get more out of.

I started with the bits I could afford, and built it up from there.

The most painful part is the "while you're in there" logic. For example, it makes perfect sense to tackle related jobs while you have that particular area disassembled but it's simultaneously hard on the budget and in some cases causes frustrating delays. My wife would tell you "That's part of the fun..." but when you want to drive it and the engine is in pieces it can be frustrating to say the least.

You'll find that everyone has an opinion on the modification subject. Find a way to organize what you learn and make a plan for your build. I highly recommend the rolling approach. If you plan out your build you can keep it drivable for much of the time, and that's the real goal anyway.

Enjoy the ride. When you get frustrated walk away. Take pictures and post them often.