Lizard928

This is probably against my better judgement due to how things tend to spiral out of control on this forum. But I have decided to do this anyways.

Please keep in mind BEFORE posting that if this turns into a turbo vs. SC thread or air/air vs. air/water thread that I WILL be locking it as soon as that transpires.

This thread is NOT about what is better or worse, it is simply about what I have completed already, and what I am going to be doing to the car.

If you have a question about why I am doing something then ask, if you don’t agree with why I am doing something then give a detailed reason WHY. I don’t want to see any responses in hear saying “that’s stupid to do that” without a reason as to why.
I hope to get more ideas and thoughts which will aid me in making the project;
a) easier
b) better thought out.
c) faster

So again if you feel like slagging something or posting something harsh to another member here, close this thread and don’t come back!

Thank you in advance for that!

Ok the project is taking place on a 1981 Euro 928S chassis.

When I got the car one of the PO s had put S4 bumper caps front and rear. They are real pieces and not fibreglass so that is good, though the mating job isn’t perfect, and the paint was horrible.
I picked it up with a blown engine which had already been torn out.
It had a head gasket failure and hydrolocked one of the cylinders cracking the cylinder and destroying the piston.
It did however come with a factory replacement block and NIB 97.95mm pistons with rings and pins.
Everything was there to bolt the engine together and get it running except for bearings, gaskets, and the new block needed to be machined out for the larger pistons.

I decided against doing that as the chassis was already not original.
Instead I recouped some of the cost of the car by selling the entire top end (heads, cams, intake and CIS). I still had the block and pistons and didn’t get rid of them till awhile later, those went to one of the racing fellows on here when his engine grenaded.

Now I already had an engine, brakes, and electrical parts from an 86.5 US car sitting around. So I asked a few of the more knowledgeable fellows here on rennlist about transferring those pieces into the 1981 chassis.
The response I got was not good! Basically it would take WAY too much time and modifications to make it work.

I said to hell with them and did it anyways. I tore out the interior, fuel tank, every piece of wiring etc.
Now this car was an auto, but I know that I wouldn’t leave it an auto as I really wanted a manual car.
So I managed to get a factory bracket for the clutch and cut a hole in the firewall and welded it on.
I then installed the 86.5 wiring into the car, along with the brakes, newer cross member and the likes, I did however leave the auto in it for now.
Everything bolted right up and in except for some wiring that was required to adapt the S4 lights to the 86.5 wiring.

When I was done I crossed my fingers and tried to start it. Well I had the fuel lines hooked up backwards, and that cost me a damper, swapped those and it started but wouldn’t idle or rev. It would just surge.

Now is a good time to explain that I had purchased this car and gotten it to this stage in roughly 3 weeks, while holding down a full time job. Let me tell you that there were some late nights there. All of this was without any real power tools either.

I traced wires for a couple weeks, everything checked out fine.
I then took it to a shop and lets just say that turned out to be a nightmare, crappy communication, buying parts without consent, lighting the car on fire then using a non halon extinguisher to put it out and not fully cleaning up the mess. Oh and they did a crappy repair on the wires that they crisped, and didn’t tell me about it.
Also insulted me when I had a friend phone and ask what was happening with the car.
Anyways I went and got it unresolved and towed it home.
As soon as I got it home I reached up into the dash and unplugged the instrument cluster as that is the ONLY thing I hadn’t checked. I turned the key and she ROARED to life and settled to a nice idle. She revved properly and responded normally. The problem was the tachometer.

So she ended up then sitting for abit as I had another 928 now, and was working out of town. I left her for about 6 months and came back hooked up the battery and she roared to life.
I ended up putting her on the road still with the auto (which was claimed to have been rebuilt RIGHT before the engine blew) and drove her for a week and the automatic tranny let go. I now had all the parts for a conversion to a 5 speed so I towed it home and removed all the auto parts, and installed all the 5 speed parts.
The car then drove beautifully.

I then decided I needed to tinker more as I needed a project, so I converted to MSII V3.0 w/ EDIS and have been playing with that.

Now I have always wanted a 928 with boost. But I wanted turbos. Not slagging anyone elses work, its just my preference for how they work behave etc. No one had even a thought of a TT kit, and I didn’t want a rear mounted single turbo setup.
Sooo I came up with a bit of a build idea.

I have decided to go with ITBs for throttle response.
I will be drysumping the car, due to the crappy factory breather system, and better oil cooling abilities.
I will also wanted to go with an electric waterpump.
And mounting twin turbos to the car.

I will be using Jenvey throttle bodies for my ITBs, I will be making a custom pan from a factory pan and just welding to it. I still have to finish the pan though I have it machined with the needed holes.

So I decided to start with the turbos.
I have mounted them near the front of the car. And have made a log style manifold, While an equal length or runner manifold is nice, they cost a lot more to make, they take up a lot more space, and imo for this build are not worth it. (I have pics that I will include following this post).
So I mounted the turbos pretty far forwards, this necessitates not having AC, smog pump, or factory PS (don’t have it in there anyways), as well I am having to move the alternator.
I will be mounting the alternator on the top middle of the engine where the SC guys are mounting the votech style units.
I have enough room to run a 3” stainless exhaust leaving the turbos which is plenty of pipe.

Now I already have the turbo manifolds done for mounting the turbos,
To make them I had a water jet cutter cut me flanges to mate to the head and to the turbo out of ½” plate. I then used weld el’s and 2.5” pipe to construct the log, there will be no lack of flow from this size, though it may be alittle bit of overkill.
I still need to punch a hole in there (will be done soon) and run piping for external wastegates. Though the turbos I have now are mainly for mock up have internal WGs I really prefer externals. Mainly for space coming off the hotside of the turbo.

That said I also want to run a large air/air intercooler in front of the engine. *Again this is my preference.* However I do not want it to get heat soak from the rad, and I want to lower the underhood temps. Which can be abit hard with turbos.

So I have decided to split the rad, and relocate it.
Now that being said I want to make a custom body for this 928,
Keeping the lines, but going with a widebody like Porsche did to the 924/944 GTP cars, with boxed front and rear fenders open at the back to smooth airflow abit.
Doing this will allow me to have abit more room for the radiators which will be mounted in the front of the fenders, just in front of the the front tires. I will be adding a few inches on either side, enough to comfortably house a set of 305s under there. This should give me enough room in front of the tires to mount a large enough rad for sufficient cooling.

Now I will also be ceramic coating all the hot side, as well as header wrapping it to attempt to keep as much heat in the exhaust as is possible, and out of the engine bay.

By putting the rad into the fenders this will stop a lot of heat soak into the IC, I also will be shrouding it in to get as much air from the front through it as is possible, I will then have a reverse scoop (like the GT40) taking all the air passing through the IC to the topside of the car. This should result in lower charge temps as well as reducing the amount of lift on the front of the car, and the amount of air which is able to get under the car in the first place. All the air passing through the rads would exit through the rear of the front fenders, just infront of the doors. Not allowing it to get under the car is my main goal with that. I will also be deleting the pop up style headlights and mounting 2 HID projector lenses in the front of the bumper.

Now I also stated before that I wanted to go with an electric waterpump. The main reason for this is to be able to ditch the factory waterpump. I will be using a unit like CSRs remote water pump which supplies between 35-70GPM of flow, which will be more than suffice for cooling. I will have to modify the coolant bridge to not reroute the water back into the top of feeding the WP as it is now, but have a hose which transfers it back to the feed for the electric waterpump so as to retain the factory thermostat.
I will also be adding a filler neck to the coolant bridge and eliminating the plastic bottle in the engine bay. I can then route the heater hose straight back through the V of the engine. Getting it into a more tidy place.
Now the factory waterpump, I really am not a huge fan of it. It works, but could be better as the impeller isn’t needed.
So I plan on having a piece waterjet cut the exact same ouside shape and holes as the factory piece. I will then attach a post to this in the center of where the pulley sits on the factory pump, I will have this machined to accept a proper size needle bearing and have a pulley machined up which would attach to the outer race of the bearing. This should provide a much longer life to the assembly, and make changing the bearing a synch.

For the drysump I will be using a dailey engineering pump with aerator extractor. This will be mounted pretty low on the passenger side of the block.

The ITBs will be Jenvey and will have a dual plenum system which will mate to a single pipe exiting the intercooler.

Now the intercooler will be wide, but considering pretty short, it will have two inlets at the bottom and one out the top. I prefer ICs that have a lot of short runners, over ones that have a few long runners. From my research having lots of short runners is much more efficient. Again this is my research and preference, some will differ with me most likely.

I will also be having a mechanical pump drawing fluid out of the tranny, going through a cooler and the spraying the gears with cooler oil in an attempt to extract heat out of the metal.
I would like to have a proper LSD unit such as a quaife and think that someone should send them an open diff of the correct year so we can get a pricing idea and start a group buy on it as I believe there should be enough interest.

I also am removing the brake booster and the factory location for the clutch. I am dumping these and going to a Wilwood floor mounted dual master system with balance bar, and floor mounted clutch pedal. In the brake line going to the rear I will have a 6 position detented limiting valve to be able to control the rear bias easily and change the bias should the roads become really slick.

Well I hope you enjoyed the read, and have a constructive comment on the project, but please again, no wars as to what is better/worse or I will be locking the thread.

If we stay on topic (and out of the wars) I will revive this topic every time I manage to get more done and closer to the finished product.

Cheers!

And I hope this has inspired you to take on a wild project of your own.

Pics to follow this post.

Lizard928

Tacked together



passenger side complete











Enjoy!

Mike Simard

Can you sumarize that?

That looks like a nice location for the turbos. Isn't it tempting to just get it running with the turbos ASAP?
I look forward to seeing more!

I nearly did floor mount foot pedals before eventually fabbing up my own. The large radius of the footbox floor keep the pedals a little bit further back but it's doable. One advantage of using them is that you can put the pedal assembly on a slider for adjustment and keep the seat rigidly mounted. That's the optimal way of building a car as long as you like pedals that pivot at the bottom.

How do the throttles at the head work with boost? Isn't a throttle on the inlet side of a turbo needed to keep it spinning during throttle lifts?

69gaugeman

Why the electric waterpump? You need the housing and bearings in it for the timing belt, and there will be no noticeable power increase.

My father has a cnc machine shop in Langley, and I have been thinking about the drysump pan for a little while. Maybe we can talk. PM me.

Lizard928

Mike that is the plan to have then be able to move abit with a fixed one piece racing seat and 6 point racing harness.

Rod, I dont like the small bearings in the waterpump, I want to go electric to be able to go to a much larger single piece bearing, I will send you a pm later today about the pan

PorKen

1981 Euro 928S chassis
S4 bumper caps front and rear
engine, brakes, and electrical parts from an 86.5 US car
removed auto, installed 5 speed.
MSII V3.0 w/ EDIS.

twin turbos
I mounted the turbos pretty far forwards, this necessitates not having AC, smog pump, or factory PS
alternator on the top middle of the engine where the SC guys are mounting the votech style units.
3” stainless exhaust
To make {the turbo manifolds} I had a water jet cutter cut me flanges to mate to the head and to the turbo out of ½” plate. I then used weld el’s and 2.5” pipe to construct the log

ITBs for throttle response
Jenvey throttle bodies
dual plenum to a single pipe exiting the intercooler.

large air/air intercooler in front of the engine
split the rad, and relocate it.
intercooler will be wide, but pretty short, two inlets at the bottom and one out the top.

custom body
widebody like Porsche 924/944 GTP cars, with boxed front and rear fenders open at the back
radiators will be mounted in the front of the fenders, in front of the the tires.
reverse scoop (like the GT40) taking all the air passing through the IC to the topside of the car.
deleting the pop up style headlights and mounting 2 HID projector lenses in the front of the bumper.

electric waterpump
unit like CSRs remote water pump which supplies between 35-70GPM of flow
adding a filler neck to the coolant bridge and eliminating the plastic bottle in the engine bay.
Now the factory waterpump, the impeller isn’t needed. a piece waterjet cut the exact same ouside shape and holes as the factory. attach a post to this where the pulley sits on the factory pump

drysumping
dailey engineering pump with aerator extractor. mounted low on the passenger side of the block.
custom pan from a factory pan and welding to it.

mechanical pump drawing fluid out of the tranny
going through a cooler and the spraying the gears with cooler oil

proper LSD unit such as a quaife
someone should send them an open diff of the correct year so we can get a pricing idea and start a group buy

removing the brake booster and the factory location for the clutch
Wilwood floor mounted dual master system with balance bar, and floor mounted clutch pedal.
6 position detented limiting valve to control the rear bias

kjurkic

Lizard, I will be spending quite a bit of time over in the Nanaimo area May-July this year, but plan to get onto the mainland for a day or two. Can I come over & hang out at your garage sometime? Steal some ideas?

Ken

bcdavis

Sounds like an awesome project! Good luck!

Candleman

Absolutely stunning... I can't wait to see how this turns out. Lizard you are a DIY prodigy.

Mike Frye

OK, I just read Porken's abridged version and looked at the pretty pictures.

I LIKE IT!

I wouldn't recommend the cardboard oil pan baffle, but hey, that's just me.

Great post and great work! Good luck with it.

90 S-4

I'm with you on the electric water pump idea, I also bought a CSR mdl 925
pump and have been testing it on another test mule/car to see if it's a good
enough piece to use on my S-4 mtr. So far, only 200 miles it's been very good.
It only draw's about 12 amp's, can be remote mounted virtually anywhere, is
quite & the best part is it flows a lot more at idle and low rpm cruising ie:stop
&go traffic. It's also rebuild able & when it does finally expire it won't destroy
the front of an engine block. You will need some sort of overflow tank though,
I bought one of the CSR unit's. The come in a variety of sizes and can be remote mounted anywhere as well. As long as your addressing the poor cooling
system, you should look at converting to a reverse flow path -- I'm going to.
If you make that piece that bolt's on in place of the oem pump, make two & I'll
buy the other one from you. You've got an awesome project going there !!

marton

Fabio421

I like how you took an old fron clip to use for mock up. Which turbo's are you using? I'm not crazy about where you mounted the turbo's. It's unecessarily complicated to mount them there with no real benefit that I can see. You could mount them with log manifolds and still kept all of the stock accesories. Either way, its cool to see someone else tackling a TT 928. Please keep this thread updated with your progress.

JEC_31

HOLY SH_______________________________T!


This is going to be good.

Kudos to all your decisions.

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My only 0.0002:

A) you're going to need a lot of R&D to not kill the motor with a drysump mistake (like MA).

B) you're going to have to get creative for the heatsoak issue.

heinrich

Excellent work Colin