Thought I would show the steps I took and am taking to twin turbocharge my '90 Testarossa. Bear with me b\c I don't even know if I can post a pic. The last car we did was my '89 C4 Vette. Troy Trepanier from RadRides helped with the conversion. The car started out blue, we then updated to a dry sump oiling system and hung a ZR-1 rearend end, doors, and side mouldings on it to accomodate the 345X19 wheels/tires, then repainted it Daytona Sunset Orange. Image Unavailable, Please Login Image Unavailable, Please Login
The first thing we did for the TR build was to buy an engine from PartsPlanetPlus out in CA. Next we made a fixture to hold the runners so we could machine them for injector bushings and remove any additional aluminum casting. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I go with my TR with up to 1,3 bar boost ( around 19 psi ) and had never trouble with the injectors coming out. sure for boost more than 0,4 bar I need additional injectors, but those are in the tubes between the aircoolers and the intake manifold. so I wonder why you modify the manifolds for the injectors? could you please explain why? thx
Can you please in a nutshell explain the plan / steps ? What parts were re-used and which parts were new bought ? Planning in time and budget ? VERY interesting project imo ... good luck !
We converted to 12 electronic fuel injectors, from this photo you can see the injectors, fuel rails (note: end of fuel rails setup for O-ring fittings) and fuel rail hold downs...Also we retained the stock runners, plenums and throttle bodies. The way the stock throttle body is mounted/plumbed reduces the the number of 90 degree turns the air has to take in the stock configuration (4 - 90 degree turns) , this should help with high speed airflow/hence HP...In search of reducing weight, the removed K-Jet weighed close to 36 lbs. Image Unavailable, Please Login
Mel, Plan was to retain as much stock componentry as possible. I did buy another complete engine from a wrecked car to preserve the original engine. The engine came with spare trans and 3rd member. I've got a new quill shaft from Robert Hayden and will probably use with either Phil's or Newman's upgraded diff. Every part I've taken off the car is labeled and boxed in case I ever want to put the car back OE. The goal is to have a 3300-3400 lb car with 600 HP, we've already dyno'd the engine and it exceeded my expectations. It made the same torque at 7500 rpm that it did at 3500 with 6-7 psi boost, so a nice broad torque curve. Initial cut will be with stock rods and pistons, but will probably upgrade to titanium rods and JE pistons when I decide to turn the boost up. We also converted the car to CCBs from a F430 Scuderia and mounted 5 spoke 16M wheels to further reduce weight and help with the stopping. My oldest son has been the driving force behind the project, he's in college studying electrical engineering. He loves the exotic supercars. We work on the project together in our spare time and hope to finish it by Spring.
sounds very good ! ! ! you will use aircoolers? I think with only 6-7 psi there is no need with the original ignition and injection it is like a double six cylinder. so you keep this system or put in/on a completly other system? so you let it run like a real 12 cylinder? I wonder why you make so much work only for 6-7 psi??? for this the original injection and also ignition would be more than good. this all what you do is more like for boost around 14 to 20 psi. or is this only first step of upgrading? important is for higher boost that you may cool the pistons with the oil from the crankshaft. the tinanium rods you only need when you want to go with higher rpm. otherwise it would only increase the costs much more. good luck
Turbo-Joe, Even with this low boost, 6-7 psi, it met my HP requirements (600HP) for the project. These OHV 4V engines are phenomenal for making power so easily...I want to walk before I run with this thing. The plan is to get it running in this configuration w/o intercoolers..I have access to 100 unleaded fuel so this is what it will burn. When we fab it up in the car there will be provisions for intercooling made in the cold side plumbing. Two EFI systems run the engine as 2 - 6 cylinder engines. We use closed loop wideband air fuel ratio control for each bank. We are using CDI ignitions so the rpm is no longer limited to 6800 rpm with this approach. Two systems also offer a wider band of EMI protection and a possible limp home mode if one ECU fails.
I loved seeing your C4 in the magazines. Beautiful car, much respect. Can't wait to see what you two guys end up doing with your Testarossa.
Raysur, Thx for the kind words, still drive that car today. Had a lot of good guys help with that Vette. A special thanks goes out to Harry Hruska, Steve Grebeck, John Lingenfelter, Mike Moran, Dan Jesel, Gordon Stoney and last but not least Troy Trepanier, the whackmaster for their assistance! JM
hahaha good idea going home with only 1 ECU if the other fails. then you just can make it so when you only cruise a little shut off 6 cylinder so you save fuel. nevertheless: nice project and good luck
Hello timemachine; The upswept headers on the Corvette are the work of a true craftsman, being that they are "2" part...any leakage at the slip joint connection?...also if I may inquire...what state/city are you located?....also on the intake runners you have shown being machined, are you going to grind to match the radius profile of the runners after the initial machining?.....Mark
TJ, That's why I love you German guys, always thinking...I used to work for Bosch and have my products manufactured in Germany, love laugen bretzen too! Maybe at a certain vehicle speed and load I could shut off every other cylinder, there is a CAN bus that runs b\t the 2 ECUs, so something like this might be worth trying, not sure though b\c on most cylinder deactivate systems they close the int/exh valves on those cylinders and the trapped air serves as an air sponge... John
GM Mark, Live in Brighton, MI...just bought a '09 Scud at San Fran Motorsports last month, small world. Evan and Doug are great guys there! Anyway the slip joint is a dual slip and allows movement but never leaks. The pipe is encapsulated in like a sideways "C"... I'm assuming u'r referring to the exterior of the runner, this will all be deburred and then repowder-coated once everything is done. John
Attached pic shows the 321 SS merge pipe we made to join the 2 headers together on each bank. The SS flanges also have the factory taper incorporated into them to provide a leak free interface. All other connections will use V-band clamps, even on the turbo turbine housing. Tubing is 3" in diameter on the outlet. Image Unavailable, Please Login
V-band clamps are the best you can use and also very easy to install and to remove - and last for ever
I removed the Larini exhaust and stock muffler (with mounting springs), the Larini exh. was 23.5 lbs and the muffler was 47 lbs. Also removed the clutch sheild, air cleaner and rear sheild, this weighed another 15 lbs. So roughly 85-86 lbs out. Image Unavailable, Please Login Image Unavailable, Please Login
Next I weighed the turbo with all the hot/cold pumbing (including wastegates) and the header merge pipe and each assembly weighed 30 lbs...So the turbos and plumbing are actually 10 lbs lighter than the factory muffler w/Larini exhaust. If u were to include the pup cats (9.5 lbs each) this would be a total weight reduction b/t stock exhaust and twin turbos of roughly 30 lbs... Image Unavailable, Please Login
Here's a pic we made of a bracket that supports the throttle body in the single 90 degree configuartion. There is one for each side. We also made a plate/flange assy that on one end, bolts to the stock throttle body and on the other end it has a round flange to go into the stock rubber coupler (b/t the manifold & TB). We retained the stock coupler and clamps for this. Image Unavailable, Please Login