2001 Porsche 996 LS1 Conversion Thread by 1dirtyZ

9 minute(s) of a 276 minute read

well i managed to clean the engine compartment yesterday, its amazing what a wire brush can do 

i still have a few spots left that have some gooey gunk i have to scrape off but its pretty much ready to be painted .

i also took the rear inside carpet that was melted from the fire and found a little nasty surprise ,,, lets say i have to scrape and clean some more in there ( sorry no pics , forgot the camera )

i also ordered the missing suspension stuff , should see it in a week or so .

i have to get some kind of adhesive insulation to stick in the engine compartment , and i guess i could start the mockup process now

made some progress today , i took out the rear carpet ( fire damaged ) and found a little nasty surprise underneath it; i found a puddle ( still wet) of melted foam insulation - it had the consistancy of tar.

needless to say it was fun removing that stuff with napkins 

here is a before pic :

and after it was done ( still needs another coat and then some insulation ):

i also finished cleaning and prepping the engine compartment , should be ready to paint next time

i also have a pretty good idea how the engine cradle will be , it will utelize the stock engine mount location and wrap under the engine and attatch to the existing removable crossmember. the engine will use vette style engine mounts that will attatch to the cradle. that way all i have to do to remove the engine is unbolt the cradle and the xmember (6 bolts ) and the engine drops down just like the original did .

i should have the tubes bent and ready to be welded and installed by saturday i hope

02.20.10

to tell you the truth i'm not that worried about the rear end partying all over the place , porsche engineers have been slowly but surely eliminating the wild oversteer that these cars were known for since they first came out ; on the current 997 models the handling is nutural and not "oversteerish" ( i know cause i drove one around a race track ). so i have faith that this car will handle properly ( not that the new engine combo will not change some of the cars handeling charachterstics ) 

any how , back to the updates 

i think i scored a stock muffler for the car , and i also got a set of sway bars for it too ( i'm missing the rear one ) , and man are they dinky ! 

i also finally decided on going with an ls3 accessory drive system ( G8 or holden style ) for ease of replacement and "shalowness" 

i'm also contemplating on going with an Fbody oil pan instead of the GTO one i have now , cause the use of the fbody pan allows me to lower the engine a bit more . only problem is that it will have the sump in the back of the engine ( towards the front of the car ), which might cause oil starvation issues during hard launches. i'll be researching it some more.

anyhow , i started the mocking up process by first hanging the plastic engine with bungee cords in roughly the location i think the engine will be ( need to get proper tranny measurement or get the real thing in there)

i started with the idea of running two "L" bars that would attatch the short leg of the L to the original porsche engine mounts ( or to their location) in the rear corners of the engine compartment , and the long leg of the L would be welded to the cross member (located between engine and trans ). the idea was to have it angled so that it clears the alternator and A/C compressor .

i was planning on using holden style pedestals and mounts ( just like on vette's) and have them sit on the long leg of the "L" :

but after messing with it for some time i decided to it was not going to work , first off the pedestals are not the same ( one is longer than the other ) from side to side:

(check out how the mounts are offset in the pics above , and the comparison below

second , they took too much space. when you compare them to ford or F-body mounts these stick too far out . here is how a ford mount looks :

another thing i noticed after placing the l bar on the real engine is that it would not work cause the pipe would hit the compressor ( you have to see it to understand how it happenes) so to make it work i now have to make new pipe that has two bends in it , kinda like this : (imagine another bend where my hand is )

and use f-body mounts so all i have to do is weld two tabs on the cradle and drill them , then attatch the mount to them . furthermore, i have the option of going poly later on if i need to .

so all in all , i think today was somewhat productive 

next on the to do list :

- get fbody mounts 

- bend new pipes for cradle 

- get accessories 

- find transmission measurements ( from mount holes to bellhousing edge )

- start figuring out which porsche wires i need to use 

- install suspension parts as soon as they get here

02.22.10

i'm trying to keep everything in the same location when it comes to the accessory drive, so the cradle has to make its way around them . ( see below). i do have a remote water pump and all the fittings, but like i said , i'm trying to stick to stock .

i'm waiting to get some critical measurements from under a car with the trans intact so i know exactly where the engine will sit and wether to go with a remote pump or not. as for the trans it most likely will be a the stock six speed G96/50 that originally comes on these cars ( from the picture you posted they seem to hold up well )

by the way , what trans and clutch is that porsche using ( and what engine if it is different from stock) ??

otto , thank you so much for the offer , but i'll have to pass ( 1- i have them , 2- shipping will cost an arm and a leg ; i like in middle east )

irish , i plan on using both ls1 and porsche pcm's ; ls1 pcm to contol the engine, and the porsche one to do everything else, the plan is to connect vital signals from the ls1 ( like temp , map, oil pressure , etc ) using porsche sensors . that way all the pcm knows is that the original engine is still there 

any ways , on with the updates 

i decided to ditch the original design i had for the cradle in favor of a much simpler and more convenient one . simply put its a giant "u" from one porsche engine mount location to the other with two parallel bar running fron to back underneath 

and from this picture you can see it does not show when the bumper is on :

the only thing i have to decide on now is wether to make it a completely bolt in cradle or weld it to the leading edge to the crossmember ( which is removable )

another concideration is a slightly different design which does not attatch to the crossmember and terminates just under the ls1 engine mount , this way i can use the porsche engine mount and solid mount the engine to the cradle ( i think this is how renegade does their cradles ). 

i might sound like i'm complicating things right now , but remeber , i have to have space for the turbo's later down the road 

either design i go with will have to wait a bit , since i did manage to score a stock exhaust , which i might use ( just have to go and pick it up tonight )

i'd like to place it on the car and see if it is possible at all to run it with the cradle design i have right now or not .

(why does it seem like i want this whole thing to be a bolt on process )

02.26.10

i do beleive i will need an extra pump to help with circulation some time later down the road. and i will be running an oil cooler from the begining, i just havn't figured out where to place the cooler .

any how , here are the pics of yesterday's progress:

motor mount :

crossmember plate :

engine block plate :

how it all looks :