Bean

That’s a very choice selection of cars - I’d say it’d be a decent homage to the original! Any word on the new Lotus?

I think your math might be off with the power needed Mike. Aero has a lot to do with it, but proper gearing most definitely will help. CD is only part of the equation, and you need to factor in frontal area before you can calculate how much drag - found this site which was neat to compare: http://tech-racingcars.wikidot.com/aerodynamics Not saying they’re still great by any stretch, but by todays standards they are quite small, and quite light, so I think 300HP still makes for a decently quick car (10lbs/hp) Gearing: More than a few manual cars hit top speeds in second highest gears (4th or 5th) because OD takes the engine out of it’s power band, and it doesn’t have enough power at that lower RPM to overcome drag in top gear, but can still accelerate in one lower. (IE: Did the Mazda pull redline in 5th?) Back in the day I had my 504 v6 up to a gear limited 130MPH (calculated from rpm (6500rpm), gear ratio (3.89), trans in 4th 1:1, and tire diameter (25.7”)) - and that was a carbed 604 motor with 4sp manual. I could do 6500rpm in 4th with that car, and it’s cd is even worse at .44. Just out of curious - With 3.46 final drive, .87 final drive (5th) and the same 25.7” tires - that’s a gear limited 165mph if it had enough power. https://spicerparts.com/calculators/transmission-ratio-rpm-calculator *I didn’t vet either site for accuracy - but seems fairly legit, but take with a grain of salt.

The OM606 would be pretty epic in a 505 wagon! What trans? I’m a Peugeot guy and all, but a modded 606 would have all the power and be crazy efficient as well. Get a nice hitch and it’d also pull amazing. Rabin

There was a formula car that had a special DOHC head for the N9TE block, but they’re beyond rare. My thought is this engine will never need to rival a 4G63 or a K series Honda, but they can still be made pretty damn stout with upgraded turbo and supporting systems like fuel and ignition. My goal was 300 RWHP in a daily without being ridiculous to drive. I currently have a EFR6758 Borg Warner turbo, ID1050x injectors, Dani head and cam, LS coils, cosmetic head gasket, ARP head studs, and an AEM Infinity 508 ecu for mine…. Now if I can ever get the time to dive in! Rabin

Welcome to the forum White! Sadly the Dani heads can crack as well - lots of thoughts on this, but I personally think it’s poor cooling system design that isn’t capable of self bleeding air out of the system. This to me is an issue as the head can develop air pockets which can cause massive temp differentials in the head. Redoing it so the head self bleeds (steam tubes like they do on an Ls) with the reservoir the highest point, as well as a swirl pot in the system to ensure an air free system is my plan. (I have a new Politecnic/ Danielson head) The one universal however is I’ve never ever heard of a professionally repaired head fail again. Last I read Erickson still fixed heads for $1100usd or so - which to me isn’t very much at all all things considered. Definitely on the same page as you with wanting to make great horsepower on original engines and drivetrains - they key for me would be using modern standalone ecu’s handling fuel, boost, and ignition. With modern control and turbo tech on these engines I think they could be pretty darn impressive Rabin

The panel that the rad is on is called a core support or rad support - there should be grounding trees on either side of the radiator in the engine compartment. Me too on how it turns out! Rabin

Pretty sure the hall sensor is the same as a VW distributor from a 1.8L Jetta from say 1987 (I think). They use the same distributor cap, so should be easy to source. Same wire, and same plug - so should be good if you can source the VW one. Rabin

Damn - That’s too bad! The plus side is that it should be an excellent parts car, and it’s parts will help other cars stay road worthy.

As for the lights - There are grounding trees under the dash, in the rear quarter panels, and on the core support. Also make sure the car has good chassis to engine block grounds, and battery to chassis, and battery to block grounds. I take all all electrical connections apart, clean, tighten, and protect every one - Same for the grounding trees. Rabin

The vacuum system should be a closed system in that it should be able to run, build vacuum, then shut off until something like brake booster or HVAC controls use it. It’s not going to be completely sealed, but it shouldn’t run continuously, or even cycle very quickly. I’d put a vacuum gauge into one of the hoses so you can see how much vacuum is being built up, where does it shut off, and how fast it leaks down. When I was using a vacuum pump I borrowed to test the filter head for leaks, it worked, but what I didn’t realize was that there was no set vacuum and it destroyed my freshly installed primer pump diaphragm during testing! Expensive lesson learned, but just make sure you know what the details are. If it’s not holding a vacuum at all, then you’ll need to find the leak - using a smoke machine might be the best way to figure that out… (There are DIY versions to make smoke machines online) Rabin

The subframe needs to be lowered a little so it can pull out the front. Mounting block nuts are just under the rear seat (3 bolts) on each side. Rabun

Yes - Control box basically gets replaced with the manual / switched solenoid to actuate GP’s by you. Hard starting is usually pump timing, or poor atomization from injectors from what I read. There could also be a very slight air leak that prevents fuel pressure from building quickly… Rabin

I’ve read about the individual cables to the GP’s as well and did it on my wagon just as maintenance when I replaced the solenoid. It already had the manual conversion with a toggle for applying the GP’s. If the car is hard starting even after you replaced them, it would sound like maybe there’s maybe a pump timing problem, injector spray issue, or maybe something else at play - but my first guess would be timing, then injectors. Not a lot of options for block heaters for these, most likely are the lower block heaters, or silicone oil pan heaters. Ive confirmed the turbo gas engines use a 36mm block heater and I found and tested them on the N9TE and it should work, supposed to be the same size for the diesel motors, but I haven’t tested the install yet. Rabin

Gorgeous car Evan, but are you sure you want to sell now rather than just replace the head and sell as a running / driving car? I assume your friend is @wadehilts, but if not maybe he can be of assistance? Diesel head should be dead simple to swap out, with just the cost of a head gasket really. It’s cam in block so no timing components or anything. Rabin

This would be a lot - but if you cut the intake pipes and flipped the plenum 180 degrees the inlet would be facing forwards. Would likely need to relocate the battery or you could upgrade to a newer lightweight lithium battery for clearance. Facing it to the rear like he did always seemed like pretty big compromise for packaging.

Awesome Jonathan! I’ve been looking forward to this post! I started re-reading the discussion with Keebs from 2014 and I’m shocked first of all that it’s been so long, as well as how much my parts / mod list has changed since then!

Also - Any idea what the vacuum pump draws for power?

Awesome! Does the vacuum switch you’re using have any specs? One would hope it turns on at a lower vacuum setting than it turns off at so that it doesn’t cycle so much - but it sounds like it’s sorting itself out. Have you removed the mechanical pump and assorted hoses yet? I’m curious how much quieter it is without the mechanical pump always running.

ABS struts use the same kits as the regular struts iirc - so easy to use a good race shock oil and a new seal. Dani head and cam would be great, but sorting out a good standalone would be the ticket for power and reliability. As for brakes - I had 505 turbo brakes on my 504 when I did a 3 day race school and I could track it all day long and not fade the brakes. Other newer cars could only get 3-4 laps before brake fade had them pulling in. Good pads and a good pad would be key, but the brakes are decently stout out of the box for some track fun. If you got more serious about track time / racing is when you’d need to start looking at upgrades.

That’s why it was the hot ticket for SCCA racing - basically the lightweight race special…. Interiors got gutted anyway so no need for anything fancy. My favorite model next too the ‘89 505 Turbo…

The GL-Turbo didn’t come with a sunroof so dealers or customers would often install aftermarket ones… It should be quite a bit lighter than the ‘89 Turbo…

I assume you’re keeping the reservoir as well correct? Pretty sure cars with electric vacuum pumps also run reservoirs as they can’t keep up without it. Curious how it turns out!

Sweet! It looks like it has an aftermarket sunroof which means it’s likely a 505 GL-Turbo - It was the stripped model for the folks that wanted to do SCCA SSB racing series. Base model GL spec with the Turbo suspension, brakes and power train - one of my favorite models they did.

Can you get the number off the wire? Your alternator has two more small wires than the gas cars have - usually see the big cables to the big stud, then the spade connector for the 12V reference on the voltage reg. I’ll take a peak at my xd3t tomorrow and see if I can tell you what it is. Do you have the Electrical FSM for it?

I’ve heard some diesels get the RPM signal from the tach…. No idea why that would go back to the glow plug timer/relay box though. My xd3t has a sensor on the belhousing, but I’ll see if the alternator has that stud on it. Is the wire that mounts to stud on the alternator insulated or is it direct to the housing? I’ve seen alternators with dedicated grounds direct to the housing. What gauge is the wire?