Power limits for engine/Trans/rearend?

[splitime]

As the Spiders have had a 'few' years for people to explore them... has the community found some windows where power limits get reached? This would be across all generations of course, (my main personal focus is the 1800cc motor in the '78)

Focused on typical weak links like piston/rods, transmission, clutch, rearend?

If i missed a thread covering these items, just send me that way and i'll keep learning.

[divace73]

a bit of an open ended question, maybe hard to get any answers. What do you want to acheive with your 1800, for the most part if drving 'normally' there aren't that many weaknesses (if any) if everything is maintained properly. If you want to put a massive turbo on then that would be a different story... An 1800 with twin 40mm side draugh webbers, slighlty hot cam and extractors with a suitable exhaust system makes glorous sound, the only weak point I can think of would be getting booked by the fuzz...

[splitime]

a bit of an open ended question, maybe hard to get any answers. What do you want to acheive with your 1800, for the most part if drving 'normally' there aren't that many weaknesses (if any) if everything is maintained properly. If you want to put a massive turbo on then that would be a different story... An 1800 with twin 40mm side draugh webbers, slighlty hot cam and extractors with a suitable exhaust system makes glorous sound, the only weak point I can think of would be getting booked by the fuzz...

I guess that depends on your idea of a 'massive turbo'. I have built a few custom turbo kits over the years and tend to properly pick them based off of application. Power limits of drivetrains or building drivetrains if the application requires it.

From the costs I've seen for the Webers, I can probably assemble an entire homemade turbo kit... so I tend to head that direction.

[TX82FIAT]

Agreed that this is an open ended question. It really depends on a lot of factors. Each improvement opens up other potential items that need to be solved. For Example, If you go with high compression pistons to add a few horse power you may have some issues with the engine pinging if you dont get the fuel right. If you rebuild the twin cam engine in the car with the upgraded performance items like porting, cams, pistons that give you say 150 HP. The car will hold up OK.... but how many launches do you expect before you have some type of failure in a 30 year old car. Example, the differential or something with the transmission. The never ending circle of what are the limits of power is only limited by the amount of money you want to spend. You can even find a multi valve head, put a more sturdy Russion transmmision in, Re-enforce the body to accomodate the higher HP and body flex, change out to another differential if you want to cut the axel size down. The starting point before going high end on the performance is getting what you have in great running order like replacing all the rubber bits that have deteriorated over the years and fixing any electrical issues. 150 HP on 30 year old brake hoses or an electrical problem with a fuel pump or some other component will only put a high power car on the sidelines. these cars are to be driven.

The list goes on. The little Lampreti design has a very strong block that can take a lot more power. While I have not seen a 200 HP spider I imagine one is very possible. Not real safe... but possible. Think about it. 0-60 in 5.25 seconds in a 35 year old spider would turn a few heads. So.. I'm not sure what the limit is to this engine. That is a question better answered by Guy Croft. He has an awesome book on our twin cam engines that i thumb through at least once a month.

[So Cal Mark]

sorta depends on how it's used, you can break a diff even with a stock motor

[splitime]

sorta depends on how it's used, you can break a diff even with a stock motor

I can definitely mention that it wouldn't be for drag racing. It would just be for a fun project and decent power bump.

My main uses would be around town, then I'd like to try it out at some open track days and/or Autoxs. Every car I've tinkered on has become a full blown track car, my intention is to not go to that extreme.

Typical things like braking system, suspension etc is all being addressed or refresh. To me those are complimentary once power/speed is added.

My main focus is components that just typically die due to more power, detonation not withstanding as I'll be doing my best to fully tune that possibility out.

Do our rods bend/snap?
Do our pistons just give up?
Do our transmissions have internal flex and just crumple under higher power? (not doing drag launches or abusing, i'm a rev matcher on shifting)
Do the rearends just simply go, as you mentioned even stock power can kill them?

I know I opened with such a general question, as mentioned I'm happy to read any old threads I just didn't have luck finding them... Very happy to do that honestly, I don't want to be the guy rehashing an old conversation.

[vandor]

The general rule of thumb is that the trans and rear end can live with a 150 HP engine. Of course it is torque that is the killer, not HP, but this works as a guideline. The drivetrain was originally designed for a 60 HP car, so it will only take so much power.

The internal engine components are very strong for a stock engine. Broken pistons, rods, or cranks are unheard of, unless a loss of lubrication occurs, or some extreme abuse.

The bodies were not super strong, especially the engine crossmember attachment points are weak, so those need to be checked regularly.