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Hello to All!
I just recently acquired a 1985 Coupe that has been sitting for 20 years with a freshly built 400 with lots of goodies inside, sitting on the floor next to it. It has the Nash 4+3 Trans that was supposedly rebuilt 10k miles before it was parked. I am currently trying to figure out what all I have for parts and pieces and what I need to get ordered before I start reassembling the car. The motor and trans are all in one piece with some reassembly required to put it back in the car and figure out the ignition and ECU. My biggest hurdle right now is sourcing a new ECU that will work with the build. The current ECU is an Accel Power Processor that comes with an AST laptop from the 90's that boots up in DOS. LMAO It's gotta go!
I will post more as time dictates. Here is a couple of pics of the fun stuff!
There a quite a few good options for aftermarket EFI systems out there now. I'm a fan of the Holley stuff. My 85 that had a 4+3, now a ZF6-40 6 speed, has a Holley HP and I like it quite a bit. I even had it control the overdrive of the 4+3 until I swapped to the 6 speed.
I just installed a Terminator X Max in my 99 Suburban that I swapped a turbocharged 6.0 LS in to and it works very well. (I had to use the TermX Max to control the transmission. Something you wouldn't need as yours is a manual.)
You do have to do some wiring if you install any aftermarket system. Bad wiring technique will cause huge problems.
If you decide to go with Holley to run yours, I would suggest going with the Terminator X over the HP as it costs less and has almost all of the same capabilities. In fact, I'm entertaining changing from the HP to the TermX when I LS swap my 85 as the TermX can run a DBW throttle body where the HP can not.
Other companies offer their own systems and for the most part they are pretty good as well.
Welcome to the forum and congratulations on your new Corvette!! The car looks really nice and will be awesome when you're finished. You came to the right place, as there are a lot of knowledgeable people here that will be more than willing to offer advice and help you get the car back together and back on the road! I'll look forward to seeing more pictures of the car as you progress through your build!
Thanks! Thats the ultimate goal, to see what it will do on the local road course! Going to take a couple of years to be able to get it all set up to run..
Ooh that motor looks tasty. I spot a 1000CFM Lingenfelter Accel throttle body, what look like Accel big tube TPI runners, aluminum heads... you know your cam specs? What heads? What intake manifold base? Any porting? Perhaps extrude honed manifold base and runners? I wonder if your manifold base is an Accel also... if it is, that intake manifold and throttle body setup, especially if ported and or extrude honed, should produce some really interesting numbers on top of a properly spec'd and built 400....
I have always been curious what kind of numbers a 383, 396, or 400 cube small block with some max effort heads, cam, and long tube TPI setup could do. I think a lot of other guys are curious too.
Bottom line, that motor looks awesome.
Good luck with the ECU hunt.
Personally I have been considering the FiTech TPI setup for my 1985. Pretty inexpensive at sub $1000. It does require a small cap distributor though.
Ooh that motor looks tasty. I spot a 1000CFM Lingenfelter Accel throttle body, what look like Accel big tube TPI runners, aluminum heads... you know your cam specs? What heads? What intake manifold base? Any porting? Perhaps extrude honed manifold base and runners? I wonder if your manifold base is an Accel also... if it is, that intake manifold and throttle body setup, especially if ported and or extrude honed, should produce some really interesting numbers on top of a properly spec'd and built 400....
I have always been curious what kind of numbers a 383, 396, or 400 cube small block with some max effort heads, cam, and long tube TPI setup could do. I think a lot of other guys are curious too.
Bottom line, that motor looks awesome.
Good luck with the ECU hunt.
Personally I have been considering the FiTech TPI setup for my 1985. Pretty inexpensive at sub $1000. It does require a small cap distributor though.
All The specs as I know them: 400 bored .040 over, 10 to 1 Hypereutectic pistons, 400 rods and a cast crank. Cam specs are unknown except that it is a moderate street cam with decent idle, right now but it is a roller with hydraulic roller lifters, 1.6 to one roller rockers on Brodix Street Heads with Stainless 2.02/1.60 Valves, Cyclone headers and free flowing exhaust. All I know about the FI set up is that it is Accel runners and Plenum with the 1000cfm Accel Throttle body on top of an Edelbrock TPI manifold. 22lb Accel Injectors, larger fuel rail with an adjustable pressure reg. Have a Stock distributor with an Accel in cap coil that is ready to install. Also will be installing an Air Pump delete. The only things left to figure out is the OBD1 System. I have an appointment to meet with a local Tuner/Dyno shop next week to discuss my options and get some ideas. From everything I have been able to read this motor is looking like a real Torque Monster with close to the same torque numbers as a mildly built Big Block. When I can afford it I will be going with ARB Long Tube Headers to cap off the current mods.
Heck yeah man that motor indeed sounds like a torque monster.
The Edelbrock intake manifold base paired with the Accel big TPI runners should do decently well for a long tube TPI setup, especially if they are ported or extrude honed and/or matched at all. It is good to hear you have an aftermarket intake manifold base on there!
FYI the "plenum", the top middle part of the intake that the throttle body bolts directly to, was never manufactured or offered in the aftermarket so I do not believe it is possible you have an "Accel plenum" as it can really only ever be a GM plenum, BUT the plenum can and often is (and on your motor I would say SHOULD) be ported and or matched to the larger throttle body and runners (the tubes).
The 10:1 compression sounds excellent, and it would be great to know the cam specs at 1.6 lift as well as the exact model of cylinder heads only so that others might be able to "copy" your awesome motor down the road, hint hint lol.
Anyway, be careful at your local dyno tuner....
I got taken for a $700 ride last year by a guy who swore up and down he could dyno tune and burn chips for my modded 1991 TPI... I walked out with 240 rwhp...
Point is, there are actually relatively few dyno tuners out there these days that know what they are doing with a stock C4 Corvette ECU...
I think an aftermarket ECU and harness is your best bet moving forward, and will allow you (and all of us anxious spectators, myself obviously included) to realize the full potential of your motor.
Can't say it enough... a 400 cube long tube TPI setup... Accel long tubes... Edelbrock intake base...
Could be awesome. Talking north of 525 rwtq awesome.
OH!!! No way 22lb injectors are sufficient for this build... double check that. 22lbs is the stock flow rate...
ARH Headers should be nice. That motor absolutely needs and deserves some big long tube headers.
Also check out TPIS and their long tube headers. Long lead times generally on orders, but good parts and TPIS is one of the experts in the country on modding these cars... especially the TPI ones.
I'm just a short Ferry ride away in Edmonds. If indeed the Injectors are 22's that's not going to cut it. I would be so temped to pull the Cam Shaft just to figure out what it is. I would think that by loosing. up the Rockers a lot and rolling the engine over on a engine stand you could pull it out wile leaving all the Intake and Lifters in place. I'm very happy with my Rick Jones Camshaft. I might look in the Spark Plug Holes and make sure the Pistons are Flat Tops. With 400+ CI you going to need at least 1 3/4 Header Tubes. Unless your really thinking your going to run AC I would be getting rid of the Evaporator and its box now. I have done a ZF conversion in an 85 if your interested. I have the Holley Terminator X in my 1990 and have no complaints. I'm surprised the Accel is not a Gen 6 or 7 it must be really old. Holley and MSD long since killed these off so there are no parts or service for them anymore.
Welcome and congrats on your new project - looks fun! Certainly a lot of nice hardware there at least for back in the day. No need to pull the cam to figure out what it is - with a degree wheel and a dial indicator, you can figure out all the cam specs without pulling it. Also, that Accel ecu should be pretty tunable, and it sounds like you got the software for it (don't throw away the laptop without copying the accel tuning files first - can run them from a command prompt in newer windows). Play around with it first, and it will help you figure out what's lacking to make a more informed update decision.
Welcome and congrats on your new project - looks fun! Certainly a lot of nice hardware there at least for back in the day. No need to pull the cam to figure out what it is - with a degree wheel and a dial indicator, you can figure out all the cam specs without pulling it. Also, that Accel ecu should be pretty tunable, and it sounds like you got the software for it (don't throw away the laptop without copying the accel tuning files first - can run them from a command prompt in newer windows). Play around with it first, and it will help you figure out what's lacking to make a more informed update decision.
Tom (Seattle)
Dear Tom is your car a Twin Turbo Callaway or is it just Nascar ducts on the hood? It looks very tuff with just those two simple inserts but they look like business!
02-08-2024, 02:13 PM
New Owner of an 85 C4 in the Pacific North West
