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Project Mj?lnir - Volvo 850 NA - ITB

Johann

Member
Joined
Aug 19, 2006
On request.

As already posted on this forum I started a recreational race car project a couple of years ago mainly out of curiosity. Wanted to see what was possible. Main goal was to make it work, second goal was to make it fun. High power was never a goal in this project. I guess the right word for the power goals was "adequate" .

In contrast to other project I started with giving the project a name instead of a number which I did with the white car projects. Reason for picking a name was because the car wasn't white.

Reason for picking the name,

First there was a plan then came the name. The was to build a dedicated car for usage mainly over at the N?rburgring or at track events. I don't have a racing license but in my country there are trackdays where you can drive a car on track without a license. At the N?rburgring there are the "touristenfahrer" days where you basically buy a toll ticket to drive over 20.8 km of toll road.

Basis had to be Volvo 850 because this is the car I have been working on for years. The one thing I wanted to different this time was the engine. Instead of going Turbo I wanted to go NA. Given the speeds reached with turbo cars over at the N?rburgring and the level of racing I wanted to do I figured that a lesser weight car with a shorter ratio gearbox and crank power near 200 HP would be plenty for starters. This would allow me to drive under 10 minutes lap times which is just about right to have good fun. I figured that if I could improve the roadholding of the car as well as my driving skills over time the lap times could go down to 9 minutes which is fast enough for me and also a sort of safeguard.
The Volvo 850 NA comes in two flavors, 10V and 20V, and to get me as close as possible to the eventual power level the choice for the 170 HP 2.5 20V was obvious. Basic tuning parts for this car were limited. In the last couple of years there are a few more parts available like cams and some other small stuff but end of 2006 when I started the project there wasn't that much to be found. Eventually I planned to pick a completely stock engine, shorter final drive gearbox, LSD and a standalone engine management so I could figgle with the car myself instead of bugging tuners all day. Another reason to go standalone was to get rid of the MAF which didn't suit my plan. My plan.. the plan I had been thinking about for years, how would a 5 cylinder Volvo engine sound with 5 individual throttle bodies.. :oogle: There was the reason for picking he name. ITB's. Sounds like.. a typical hammering sound. A hammer.. a powerful hammer.. I guessed the most powerful hammer known to mankind was Thor's hammer :rofl: The name of that hammer is Mj?lnir.

Mjolnir_metallic_1_white.png



How it started,

I had a plan and started to work on some details. Pretty soon it became obvious that starting from scratch using new parts the ITB setup would become a costly exercise. There have been 5 cylinder ITB's setups used in racing before but those were based on the newer RN type engine. Jenvey did have an ITB bridge available for this engine but I wanted to use the older 850 5 cylinder engine which uses different intake ports. The only option was to make a bridge myself.

Having access to CNC equipment I designed a bridge in CAD.

cadmanifold.jpg


After which the CAM parts was put to work,

mill1.jpg


mill2.jpg


mill4.jpg


While all this was happening I ordered 5 Jenvey TB's including the throttle linkages and stuff.

tb1.jpg


And after all was finished everything was bolted together,

idlemod.jpg


Picture shows the third or so revision of the setup, overall building the intake was very time consuming. Adding the throttle cable setup also took a lot of time but eventually it all worked out.
 
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Next,

ITB's is nice but not without a car. Of course I needed an 850 to realize my plans but with the bigger picture, specially the costs, in mind the basis needed to be something cheap or incomplete. Since nearly everything had to be changed a rolling body would be enough but are near impossible to find because often these cars are offered to wreck yard to get rid of the tax burden. In my country a car will always cost you. There's road tax and insurance. If the car is road ready it needs to be insured even if it's parked on private property all day. Also road tax needs to be payed no matter what. If you don't want to pay insurance and road tax the car needs to be decommissioned but this is only possible for one year. For a car less than 15 years old it still will cost you some 70 Euro's per year. Wrecking the car are report for export is basically the only way to get rid of the costs of owning a car so for this reason not many half baked rolling bodies with the proper paperwork can be found. But I was lucky. I found a pretty complete body with half an engine between the parts ad's on a Dutch internet marketplace. After contacting the owner we agreed on a price of 300 Euro's unseen and a few days later I went to pick up the car. At first sight it was a bit of a misery to see but looking beyond that I was pretty happy with it because most of the basic needs were present except the engine.

1.jpg


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So.. October 2006 I was the happy new owner of a wreck.
After bringing the car home first thing to do was to strip everything which I did outside my "shed" in the cold, very cold.. :grrr:

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The old engine and AT transmission were a mess,

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I also sourced a new engine and a short final drive ratio gearbox during this time,

spareeng.jpg


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Somewhere in between the other work a Quaife LSD was installed,

quaife.jpg


After about a week or so I had most of the car stripped to the bare metal,

empty1.jpg


empty2.jpg


Except for the underbody and suspension and put the car on the auto lift in my nice and warm shed,

autolift.jpg



empty3.jpg


While cleaning up the engine bay and removing the isolation material from the interior I took measurements for the roll cage and ordered the tubing which arrived shortly before X-mas. Our company was closed in the week between X-mas and New Year so I pushed the car to the workshop where there is a welding shop with the proper equipment to give welding a rollcage myself a try. My son was the first driver of the car at that point.. :)

Since I only had a couple of days between holiday family stuff I didn't take to many pictures of this parts of the build.

The dash took some time to fit,

dashcage.jpg


And soon it started to look like a real cage,

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A nasty but fun thing to do.

While having a crane available I thought it would be easier to fit the spare engine while at it,

engin.jpg


And while being light weight before the engine went in I mounted the KW suspension,

lowsdm.jpg


After that is was back to the shed and time for a new year's party...

To be continued
 
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2007, the year in which all should happen..

Back in the shed the basis for the project was ready. To do list was huge even considering there's not that many parts in the car.
While stripping the car I took out most of the wiring.. Bad decision. Being the first attempt at some point I though it would be easier to take all the wiring out and make everything new. For whatever reason I was smart enough to remove the wiring without destroying it. Left all connectors intact and also pulled full cable length instead of cutting it all to pieces. At a given point it showed that rewiring a car from scratch is a ****load of work.. So.. The stock loom had to go back in but only the wires needed and no more than that. It turned out to be a huge puzzle. I was lucky to receive an older wiring diagram from a friend of mine, newer Volvo wiring book have a lot less information. A couple of evenings I was busy hunting colors and connectors and seperating looms to minimize the amount of wiring. Added to that a standalone ECU also had to be wired in..

engin2.jpg


Choice for a standalone was made earlier on and I chose to go Link,

Received a G3 at first,

link.jpg


but it turned out this ECU couldn't do what I wanted it to do. Lucky for me the supplier agreed to take it back and a LinkPlus G2 was used instead,

link2.jpg


My goal was to use sequential injection and maybe direct fire ignition later on. The G3 was only capable of batch fire.

Wiring took a lot of time. To clear the mind I worked on wiring one day and other parts of the car the other day..

Suspension was mostly done. Front suspension was KW V2 but for the rear I used a different combination, KW race springs and Bor Chuann (MeganRacing) Nissan S13 shocks,

rearsetup.jpg


This mostly because I had these parts shelved.

The original rear sway was broken so all was exchanged for iPD sways,

sways.jpg


Next were the brakes and having had very good experience with the rather heavy but very capable R-rotor/ Porsche caliper combo the choice was simple.

Fabricated some brakets,

caliperbracket.jpg


And the BBK was a fact.

brakeset1.jpg


But only after changing the hubs from 4 bolt to 5 bolt.. ;-)

Next was exhaust. Put a "sponsor yell" out and European Tuning in the Netherlands was kind enough to provide a Ferrita turbo exhaust for minimal price.
For header I used the stock GLT header because it may be small but it is reasonably well designed. Did some minimal porting like removing weld ridges but no more than that,

exhmani-1.jpg


exhmani-2.jpg


Still using this header today btw but in time I want to change to a more "STCC" like design..

Next was the mid pipe including cat. The cat is a Ferrita/Kemira 100 cpi type, the pipe itself 2.5".

exhaust.jpg


With most of the rear and under the car fitted is was back to the engine again.

Of course there was still the wiring but the dash needed completion, the workspace needed to be done and the engine needed an airbox and fueling.

For fuel the stock lines were used up to the firewall. An FPR was installed at the firewall,

fuelline.jpg


Used a modified stock fuel rail.

To fit the ITB setup the thermostat housing had to be extended,

thermo.jpg


Used an RN type thermostat housing because it is slightly more compact.

Next was the airbox made from 3 mm aluminum and which was also my first attempt to weld aluminum.
Lets just say it did need some cleaning up.. :)

airbox-v1-2.jpg


airbox-v1-1.jpg


For clearance the radiator had to be lowered.

I do have to add that pictures aren't all posted in chronological order. Some mods to for example the intake setup were done at a later point when fitment issues or revised strategy came in to play.
 
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All wired up..

Then comes the day when the ECU needs to be powered up.. Very exciting for a first time. Lots of checking and double checking had been done but at some point you can't ignore the fact that the key needs to be turned. Laptop connected, fingers in ears and go.. Wow! all appeared to work. Next came testing the connections. The Link has some test routines for testing ignition and injector so I started to work the list. Ignition was OK, Injectors came to live one after another in the correct position. TPS worked, CLT, IAT, Lambda, Fuel pump.. Fuel pump.. No fuel pump. :omg: Checked the relay and it worked. Measured the wiring, again, to the rear and it was OK.. Hmm. With slight unbelieve I opened the, empty, gastank and it turned out there was no fuel pump.. :wtf: In fact there was no fuel pump assy at all, only the connector hanging inside the tank.
Next was trigger which showed to be connected and after that I did a first time ignition/timing setup like explained in the Link manual. A bit of a ritual but it was clear enough for a noob like me.
Timing was off compared to the reference setting in the software but the ritual explained how to correct for this but I needed an extra pair of hands but also a fuel pump. Couple of days later I sourced a Walbro fuel pump and a complete pump assy. After installing and testing the fuel system it turned out to work without leaks. Next I arranged an extra pair of hands by means of a good friend/mechanic who helped me to set up the timing with a timing light.
A bit puzzling because initially all has to be done on the starter motor which gives to low revs for a good reading. But the Link people were very clear in explaining all this. At this point I was pretty much convinced the timing was OK but my friend was a bit puzzled also because he thought we were cranking the engine with all the settings, including fuel, activated put I had pulled some fuses to keep the engine from starting until the timing was all set.
Somehow he didn't understand why the engine didn't start and why I don't wanted it to start, must add that the radiator wasn't connected also at that point. Turned out my friend totally missed the fuse part so I pushed the fuses back in, primed the pump and showed him that all the time there was no fuel pressure and added to that the injectors weren't working. This cleared up the confusion and by means of a joke I said to him that now the engine was ready to run after which he started laughing.. "yeah yeah you have the car all tuned". I turned the key and the engine started at first spark and ran amazingly smooth at near stock idle rpm. .. At that point I was totally in shock. Engine ran for a few seconds only but after stopping the engine there was a long silence in the workshop and full of unbelieve I gues we must have looked at each other for minutes without saying a word..

It wasn't the first time I started an engine after a rebuild but with a standalone being all new to me with an engine with throttle bodies being all new and the rather confusing first steps of setting up the ECU I never would have thought the engine would run.. Priceless moment. :cheers:
 
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Wrapping it up

Halfway through the list, still lots of things to do. The big things are easy,

Seat and harness,

seat-belt.jpg


Steeringwheel,

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Had the stock dash connected. Speed, RPM and fuel were working but the Link ECU can't steer the Volvo temperature gauge because it is frequency operated so I decided to add some gauge for oil pressure, temperature and water temperature,

gaugedash.jpg


Also a Jegs HotRod heater/fan was added because defogging is mandatory in my country so I needed something to blow behind the dash.

Wideband Lambda was added, car is running 2 lambda's. One wideband for actual reading and one narrowband for closed loop lambda.
Wideband is also connected to the Link.

Next came the tires. I live 20 miles from the Vredestein factory. Got in contact with a guywho has entrance and worked out a deal to get some tires for cheap. Deal was that some stickers had to be added to the car which wasn't a problem for me.

Received 225/35-18 tires and mounted them on Rial Daytona rims which I had shelved.

Next a RealCar splitter/spoiler was added to the front,

realcar1.jpg


Car was missing mirror housings and I sourced used housing in the wrong color.
As a joke I asked people at the Dutch Volvo 850 forum which color they needed to be and gave a few options.
Eventually the color choice was Apple green,

sdmirror2.jpg


And after that it was time to let the car see some sunlight,

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To be continued
 
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Let's roll..

Once the car was out the shed it was time to make it do what it was made for. The first miles were difficult. Had a very hard time getting the engine to idle well. Maybe it was because the parts were new but the idle kept sticking between 1200 and 1500 RPM and it appeared the TB's weren't coming back to their idle position. After a long search it turned out to be the Volvo throttle roll which had a dead spot. After taking everything apart and building it back up the car was idling OK.
Next came the tuning which wasn't that difficult to start with since i had a stock 2.5NA timing map available. Fuel could be adjusted pretty quick and soon the car was running medium to mid load surprisingly well. Next came the closed loop lambda because the car needed it's Dutch "CARB" like approval which went well except for the wipers and a steering knuckle which had to much play. Installed two new steering knuckles and officially the car was good to go.

sdmdrive.jpg


After that it took considerable illegal road time to get the high end running. No dyno was used btw.


A lot of the tuning was done on "feel". Never dyno'd the car and given the false butt dyno readings because of the shorter ratio gearbox I wonder if there was that much to gain with the ITB's. Power could have been 160 HP or 180 HP, really don't know, but the car wasn't slow, certainly not turbo fast but very peppy throttle response and really a pleasure to drive. Top speed driven was near 215 km/h from what I recall and getting to ~190 km/h wasn't all that slow.

All of this was more or less straight line tuning. While the tuning progressed it became time to focus on suspension because a visit to the N?rburgring was planned. During this time I also kept my part on the tire deal and added the stickers to the car..

spring9.jpg


Boy I should have known.. The car didn't have grip at all. The rear was scaring loose And under braking with slight steering angle the car would spin..
One reason was the brake balance. Because the car used to be an AT there was more initial braking force at the rear. Normally ABS has a saying in this but ABS wasn't functioning because when I bought the car there wasn't any ECU nor controller fitted.

All in all a worrisome experience specially because the Ring visit was nearing fast.

I must have spend almost a day getting the shock settings and tire pressures set in such a way that the grip level was acceptable but still braking hard ever so slightly steering input would invoke a slide. It was more a matter of getting the slides in grip than getting the brakes to do what they were supposed to do..

Only on short notice the one thing I could do was to add a trunk lid spoiler to put some weight on. I sourced a Hank Scorpio aerodynamics add on and mounted it to the trunk. At higher speeds this was an improvement but at lower speeds there wasn't much of a difference. In the end running nearly no tire pressure in the rear street tires appeared to be the best option and it was time to visit the Ring. The 265 km ride to the Ring was a challenge..
Short final drive in an empty car with stiff suspension at speeds near 160 km/h isn't very comfortable. Added to that, in the morning while the temperatures were lower there was a lot of wind blowing past my right arm. Every time when touching the shifter it was very cold. Reason was that the heater entrance was still open and there was no heater underneath..

Halfway a cup of coffee was much appreciated. After completing the trip the moment arrived where I had been working for the last 6 months or so and I was very nervous. The plan was to make a couple of easy shakedown laps. Entering the gate my hart was beating like no tomorrow but as soon as I rolled toward Tiergarten a very faint but nervous smile became a big grin..:nod: Yes this was good. Not perfect but all the ingredients for fun were present. Not quite in the right mix but that couldn't spoil the fun. Then came the corners and with the loose rear trouble in mind I tried to brake in a straight line and let the car roll through corners as much as possible but it was obvious that the rear remained "challenging"..
Still lap one was a fact!.

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Soon to be followed by another 3 laps of which 2 were timed and showed that the expected lap times could be met with a handicap. I was very happy with the results but the last lap the car showed a fueling problem. Turned out to be the FPR which was set at minimal pressure which it didn't like.

Back home the FPR issue was fixed pretty quick by upping the pressure until it showed a more stable behavior and some fuel adjustment was needed after that. The brake problems needed some more work. Removed the whole ABS unit and added a Tilton brake proportioning valve.

Also the one urgent thing to do was to get rid of the terrible Vredestein tires.. Those things were pure drama.
 
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Not having sourced new tires yet I already removed the stickers from the car and the next event I attended was a gathering at a test track of the Dutch road inspection, RDW. A friend of mine is working for this RDW and invited me for this great sunny day with included driver training and a couple of laps on the big oval.

rdw1.jpg


I have been practicing 180 degree slides on an Epoxy-water course which was great fun. Slalom exercise after that was a terrible experience because the car didn't have power steering fitted. :roll:

Great fun, time to move on..
Next day the 18" rims with Vredestein tires were history and 17" TDR Prorace 1.2 rims with Michelin Pilot Sport Cup tires were added. Roadholding instantly improved by 1000% or so,

pro1.jpg


The heat was on, time to Ring!

One and a half month after the shakedown the car was back at the Ring. This time there was no time for recreation, things were serious. Already at the first meters past the gate it was clear that, given that the car was NA, it was ballistic. This was a racecar and everything felt right. With the proper brake settings trail braking was a delight. The cup tires were like glue and the speeds reached were amazing. SX topspeed jump was only 10 km/h below my 225 km/h Threshold. Down hill the car went like the fire brigade and while keeping the momentum up the uphill parts wasn't that bad either. I soon realised that I was already hot lapping the car on it's warmup lap and after finishing the lap I decided to take another go with the warmed up tires. This time things became even more serious. Cornering speeds were extreme, the suspension had a very hard time and there wasn't a single indication that 850NA was less fun compared to 850turbo.. Whooohaa

But unfortunately the fun didn't last long.

After cornering Aremberg, a near 180 degree turn, a rodbearing let go and the fun was over. I managed to roll out the car to halfway Breidscheid exit. Although the aweful sound in the engine was almost gone it was clear the engine was done. After discussing the situation with a nearby restaurant owner I was allowed to park the car on their parking lot and picked it up together with my son two days after that.

sdmdown.jpg


Game over..
 
Resurrection..

After the engine failure it was clear that my hopes for 2007 with this car were gone. A new engine was already partially in the works but needed to be speeded up.

First the engine choice and all the crap thrown at me for this choice.
There's race, street, street-race etc. etc. Already from the first day the goals were clear. The power goals were a bit less defined but "adequate" was clear enough to tell me the power of the car as it was was basically enough to make it fun. I didn't want no quest for the last horse. The assumption that the stock engine with the ITB's and standalone made similar power compared to a stock NA engine was what made me decide to aim for similar to slightly higher power, mainly higher torque or slightly wider torque spread. To cut a lot of reasoning and "calculating" short it came down to a power goal near 200 crank HP with a fairly wide torque spread. Assumption was that 240Nm of torque could be spread a little wider. Next thing on the want list, mainly "cosmetic", was a clearer ITB hammering sound. For this to happen I had to go the uprated cams route, a costly route. Being mid year it was clear 2007 was out of the question so I concentrated on having the car finished by years end.
The base engine choice. Given the power goal a stock engine should be capable of reaching those numbers. Volvo developments regarding material choice and quality should bring some extra strength. The basic RN 2.4 NA engine had become less fat over the years, light crank, smaller piston pins, longer rods giving it a better rod/stroke ratio and pistons which were made by Mahle and also received a coating. OK, a lot of assumptions and no practice for proof since the known NA race engine's use larger 84 mm bore with a non stock short stroked steel crank. Maybe I did it all wrong but the choices made were clearly thought out and only practise will should how it holds out.

Choice for the engine base RN type block. I already had a 2001 NA engine shelved for parts as wel as a 2001 2.4LPT engine. Having had both engine's side by side it turned out the NA is an LPT without the oil feed and return lines machined. All other is exactly the same. OK, pistons are lower compression but the NA also had piston squirters and I couldn't find a difference between crank and rods. Maybe there is but not what meets the eye.
Checking both engine's the LPT appeared to be the nicer engine so this engine was used as a base. The crank was almost 4 kg lighter, the rods of the LPT engine were cleaner. Turbo oil return needed to be blocked.

b5254ds1-3.jpg


New pistons were needed. choice was second oversize stock Volvo NA pistons, pins and rings,

834pistons.jpg


Block was overbored and the deck was slightly machined to raise the pistons above deck,

b5254ds1-2.jpg


Turbo bearing were used but basically it became an all stock 2001 spec Volvo NA engine,

b5254ds1-5.jpg


This also included the new type oil cooler/heat exchanger,

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But.. With an old style head,

b5254ds1-7.jpg


Choice for old head was mainly because of the whole intake system being made for this head.

Instead of reusing the head of the damaged engine I sourced a new head.

Head came with 20 bend valves..

20v.jpg

:badboy:

Head was tested for leaks, valve guides replaced with 2001+ guides and 2001 valves with smaller diameter stem were used. Also the newer and somewhat smaller type seals were used because we needed all the travel we could get.

A very conscious decision was made about porting.. No porting was done to this very early type NA head except for port matching the intake bridge,

porthead.jpg


port.jpg


Having had endless discussions about this subject and I received a lot of advice and a lot of crap for not porting anything but to sum it all up, I don't care and I have my reasons.

For the cosmetic part higher lift and slightly longer duration cams were ordered. With the higher lift stronger valve springs were needed and custom retainers to fit the springs.

springs.jpg


To clear the cams the head needed slight machining,

camclear.jpg


Lifter buckets were changed to solid type, play adjustment was done using under bucket shims.
Because the hydro lifters were eliminated we chose to block the oil feeds,

lifterfeed.jpg


And next the cams were added,

cammo.jpg


cammo2.jpg


Meanwhile we were end October before the new engine was put together,

b5254ds1-10.jpg
 
Johann,
what power did you make on the new engine at the wheels? Do you have any dyno plots on the original motor and on the second motor?
Jonathan
 
Just before the end of October the engine went back in the car,

install-2.jpg


Another upgrade to the car earlier on was an electro hydraulic steering pump,

ehps.jpg


Two days later the car was ready to go again,

bay.jpg


Drove the car for about a week with the old management settings but it clearly needed adjustments.
Sound was a lot throatier and the engine would rev a lot easier.

New engine on old tune,


After little over a week later the car went on a load dyno nearby and after a day of mapping it finally came down to 230 crank HP with a table peak torque of 240Nm, right where I wanted it to be.. :omg:

The power steering, slightly lower pressure compared to stock, is a delight. Not overpowered but very communicative feel.
 
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