1991 Nissan Primera GT SDC5000 low buck endurance racer

Ah, where does the time go?!

Cage work is progressing a bit slowly, together with some rust fixes. Dash is back in but we have yet to finalize the rear stays, diagonals and seat belt mounts.

This weekend saw the rare occasion with three of us at home and with one day "to spare". So we set to work on ripping out engine and transmission for fixing head gasket, clutch and general checks.

First issue was driving the car in, no throttle response at all.

Well that was because I had the foot on the support bracket for some interior stuff by the ECU. Driving sitting on an empty oil can does strange things!

As we worked on we quickly added a new radiator to the shopping list. The top hose connection was broken off, I'm sure the hose would have blown off quickly. Let's hope the bad headgasket is not from a severe overheat due to that happening to previous owners...

Lifting the car up with overhead cranes is neat...

And after much wrestling the combo is out. 

New drive shafts will also be ordered. The Primera has rubber dampers on the drive shafts and they are known for capturing water that slowly (or not!) will make the drive shafts rust underneath. That's where they snap. Since the CV joints also looked doubtful, new shafts seem like a good investment.

The clutch was also really way past it's prime time, so the decision to rip things apart seems to be the right one.

Now we can work in different ends of the car. Clean engine and head off, that's one guy. Cage fabricaton, 1-2 people and then someone can start rebuilding the front suspension. First race is only 2 months away!

Gustaf

Yesterday we washed off the engine and transmission best as we could - actually probably better than I have done before. This time we had a pressure washer with hot water and industrial grade degreaser. Beats using a kettle and a tiny "steam washer" (that really only puts outs puffs of luke warm mist).

Then we made a make shift working place in a underused corner (this is my friends company workshop), and proceeded to whip the head off.

It all looks mostly as expected, some water mixed with the oil as you would expect from a leaking headgasket.

The gasket itself is not killed thy way I'm used to from torturing them with vast amounts of boost, but it does seem damaged.

I'm just hoping the head is straight enough to be skimmed into working order. Otherwise we might need to think about another solution...

The order for some new parts was sent off last night, hoping to get the stuff here during next week so we can work on multiple parts of the car, at the same time.

Gustaf

Good progress! Can't wait to hear how the head measures out.  Keep up the good work!

Moan and groan...

Last night two of us soldiered on with the engine. The other two had packing duties for easter vacation trips. Draw your own conclusions about the SWMBO's in the team :-) No, really, it's not as bad as it sounds.

I started pulling the manifolds off the head to give it a first check. Niklas proceeded to remove the sump.

The workshop we're in mostly produces heavy equipment for mining so I didn't really find a real straight edge. But I did get hold of a long caliper and that should pretty much be straight. When checking the head according to the manual it's just within tolerance for being skimmed straight. But the "worst" point (right between cylinder 2 and 3) is out. But the manual does not say to measure there. I think we will have to gamble, a 0,25 mm skim should suffice.

I got the lifters out but need a better (deeper) valve spring compressor to get at the valves.

On to the bottom end.

Yummy, or not... Yes, we really will need to pop some bearings to check the status.

Not the worst I've seen.

OK, bad but well...bad enough that we won't endurance race that. 

So it all went out, and there were bearings much worse later on. The oil rings on the pistons are also really stuck.

Two bores have some light marks, possibly from water standing the cylinder? I'm hoping a hone will be enough.

So, we went from "let's just slap a new head gasket on" to "new bearings and rings".

The old 10 has an engine we only have changed oil, filter and spark plugs on, maybe we are just happily unaware of issues but I doubt that. I think we are seeing the difference between a one-owner-since new (and now 65 year old lady at that) 27 year old car, and a 20 year old car that has had 0,7 owners per year on average. A car that was posted on a national "street car" forum, sporting cool amps, a cool open air filter and "sports pedals".

When buying crap-can race-car to be, choose old ladys car over "hey I just got my license" car.

Gustaf

Bummer dude, mud everywhere in that engine! Sounds like you're in the same boat as I was.  Would have liked a "Minor" fix like a headgasket or bearings, but now seeing it needs a whole rebuild.  Good news about your head not being a paperweight though!

FYI, bearings in both my p10 engine (spun bearing), and my b13 engine (blown HG) looked significantly worse than yours.

Another minor detail: I did not disassemble the head completely.  The head was pressure tested at the machine shop when it was resurfaced, they said the valves were sealing well.  I decided to leave them alone.  I haven't had a Nissan with a valve problem, after many many cylinder heads off.  So I have faith in it.  But that's just my opinion, and a risk I was willing to take.

Hope you have a parts washer.  That would make your life easier! 

Good luck

The head goes to the machine shop today, bearings and rings are in the mail so let's hope for a quick recovery of the patient :-)

I have a small parts washer at my garage but where we have the race car it's more a case of using the pressure wash pad. We actually spoke about getting an old dishwasher to convert for parts washing duties as we tore the engine apart.

Last night one of us soldiered on with rust, now most holes are filled with metal and sparks. They also took the fuel tank out before I arrived to remove the fuel pump and rinse.

Then we attacked the rear suspension and brakes on one side. While the long term plan is 2,25" springs with correct spring rate we need something for the car to sit on until we corner weigh and decide on spring rates. I found a cheap  (70 USD delivered) lowering kit for a turbo diesel estate P11 so we're gonna start with that.

The old shock was completely rusted out, no damping force whatsoever...

Ah, the first shiny new parts! I had to resist the urge to take everything apart and paint. Repeat to yourself - crapcan racer, not concourse! Admittedly, I suck at concourse anyway so...go figure.

Gustaf

Two weeks of business travel for me slowed progress more than I like. Last night the entire team was on again and while I attacked the front suspension, two others worked on the cage.

Rear stays with diagonal is there, and also the X in the main hoop. We're in a bit of a gap in between two rule sets here - the current rules allow a very simple cage but next year we will probably run a larger track and all signs point to using the Swedish formal rally/racing rules. We're trying to match that as far as we can and leave options to add bars as needed.

We hit a stop in the front suspension since one of the UCA bushings are truly shot. Need to get better UCAs from a parts car. But we got the springs and shocks in place, one front brake hose and also confirmed the fit of the brake pads.

We are waiting for the head to come back from the machine shop but I think we will have to start assembling the block any day now.

Gustaf

Today was the day when the engine was going together again. Key word, "was". Crank with bearings went in just fine, some extra time to clean the oil ring grooves on the pistons. And then the piston rings are too thick. All of them.

The old ones (top and second) measure out at around 1,16 mm, the new rings are 1,48 mm. Doh.

Almost broke the Internet googling, ebaying and online carparts.whatever searching. Loads, and loads of 1,5 mm rings. One supplier that lists 1.2 mm rings - in the US. But hey, they ship to Sweden and price was decent. So let's hope they do fit!

Gustaf

Despite the piston ring setback we continued with the cage, front suspension and seat mounting.

Soon we got the insight, we will never be done and ready for the first race. So we decided to race the old car, the P10, at least for the first race of the season. Depending on the results we would see if it felt wiser to stick to that one for the second race too. There's a rather long gap between race 2 and 3 meaning we might even be able to test the new car.

So "old faithful" was dragged out from the storage, started and ran as happy as ever. New oil, bled the brakes, checked the brake pads and made sure nothing obvious was loose or missing.

Most of the time was spent mounting the radio for intercom and fixing a holder for an old smartphone running Racechrono.

The weekend before the race (last weekend that is) we had a test day and took some laps. All felt good and we also gave the cup winner from 2015 the chance to test the car. Always interesting to have someone new  drive the car and give opinions. Apart from a steering wheel to small and to far away he was pretty satisfied. The wheel placement is sort of intentional to help driver swaps. You do get used to it. Sort of.

So, Saturday May 19th was the premier for 2018. We had 18 team at the start line, two new teams and three teams that had swapped cars. The lotto gave us pole position at the grid (our first!). We made a decent start but soon had to let some people by, most notably the Honda CRX VTEC that is new for this season. The VTEC with 150 bhp is almost a unicorn in the series with almost frightening potential on paper - light and with good power. But I always point out that the Primera GT set basically the same lap times in the new car tests back in 1991 :-)

They soon ran into issues with wheel bolts backing out though and after 35 laps there were 6 teams on the same lap, we had 3rd after the Opels (Astra and Kadett) of 4Sign and Skelleftereklam. The Honda was on our tail followed by the Citroën of Forsman and the BMW 320 e46 from Björnligan.

The two Opels were really quick, so was the Honda but the wheels were a problem. Then the Opel Astra of 4Sign developed a misfire and the Kadett lost 3rd gear.

In my last stint I had Forsman roughly 1/3rd of a lap in front of me. We would "meet" at a certain spot so I tried to maintain an equal gap but not overdo anything. I had the feeling they were leading, with us in second. Then I started seeing puffs of smoke from the Citroën in some turns! Engine oil? Brakes? I decided to press on a bit harder to try and close the gap if they would start slowing more.

At 115 laps with 18 minutes to go, we were in second, with Forsman in the lead and the Astra (misfires cured) chasing behind. I do think I closed in a bit before I handed over the wheel to our last man.

Now it was exciting. We were chasing the Citroën, not knowing what their problem was. And we had the quick Astra moving up behind us. Some lapped cars were acting as a buffer in between and after a couple of laps the Citroën slowed  - and we passed! With 6 minutes to go we were leading, Forsman running behind by at least 10 seconds a lap but 4Sign in their Astra was running more than 3 seconds per lap faster. But they had a gap and slower cars to handle before they could get to us.

In the end, we passed the finish line after 4 hours and 125 laps, 3.7 seconds in front of the Astra. Forsman kept third place with 124 laps and then Puma Racing was a rather distant 4th at 120 laps.

Our first win was a fact! Celebrations!

Now, we were for sure "helped" by faster cars and teams having problems. Looking at lap times there are 5 teams that were faster - we are down by 1 second compared to the fastest ones. That is 125 seconds over a race, with lap times of around 1 minute 42 seconds that is almost two laps. In theory. In reality nobody is constantly running their "fast" times of course.

This time, the old, tried and tested car ran with no technical issues. Luck or just proof that you shouldn't mess with things that work? We'll see next time out.

No video since the GoPro decided to show "SD" with a padlock, and we are waiting for the "official" photos to be released. But most of it looks just like before :-)

We had some contact again and the P10 is looking a bit worse for wear now again. Maybe we do need another P10 parts car...

Gustaf

CONGRATS!!! 

What an accomplishment!

Don't sell yourself short either, you won an endurance race.  You've gotta be the fastest car out there that doesn't break, and your team sir did just that.  

Keep up the good work. Thanks for making the p10 community proud!

Thank you :-)

Yes, endurance is the key. Funny, when refuelling I saw that the odometer just went past 205 000 kms (that's around 127 000 miles unless I am mistaken). That means we have been racing the car for over 5 000 kms (3 100 miles). Almost scary :-)

Gustaf

Photos are up at http://calemotorfoto.blogspot.se/  !

Happy winners!

Gustaf

In reply to therealpinto :

Could you give me the part # and info of the suspension setup you are running? I have found two providers here in the states for GAZ Shocks and I would like to investigate if they would be able to get your setup here in the US. Thanks in advance!

The P10 is just running normal off the shelf Bilstein B6 shocks and some no-name lowering springs.

The P11 sits on GAZ adjustables but they were custom built - I bought new standard shocks that I sent to them for conversion. They don't have P11 (or P10) shocks available and this was the "easy" option. I ordered the standard shocks from a European online store (carparts24) and had them shipped to GAZ directly. That was a nightmare on its own since that company was not used to customers in Sweden ordering through Germany to have parts sent to a UK company address ;-)

Thinking about it now, I would not be surprised if there are other bodies that would fit the P10/P11 front end and the respective rear ends, if you are allowed to use coilovers/adjustable platforms. But you would need to give GAZ the measurements of the shocks for that.

Gustaf

If there is one thing we need to work on in our team, it is to check the car up immediately post-race. We suck at that.

It has been on the trailer outside my garage since last race and only yesterday we managed to pull it down, check tyre wear (fronts are gone), check brake pads (all are fine) and work on the dented panels (well...sort of).

In doing the brake pad check I saw something bad.

Yes, that is a brake hose with a very obvious bubble. Both fronts are the same and they don't seem to like the brake heat. New hoses on order but will they make it before Thursday? Next race is Saturday...

I have a backup plan with hoses that are in stock locally that should "fit", may as well get those right away I think.

Gustaf

Race report for second race of 2018 is in.

We got some VW Passat brake hoses that sort of fit and fixed that issue on the Thursday before the race. The new wider (215) tires had also arrived and it was decision time. Do we "waste" them on the old car, or save for the new one? We had some part-worn fronts that should work for at least another race.

The cheap part of us won and we used the old worn tires. With not much more that fine tune the intercom socket and laptimer to do, we were "race ready". 

Saturday morning saw a partly cloudy track, colder than last time but no rain in sight. We were at the back end of the grid, thanks (???) to the reversed starting order. Only the new team running another Seat Ibiza Cupra was behind us.

Starting this way means a pretty exciting first stint, lots of passing and trying to keep the car mostly in one piece. This time we were lucky, and although some quick teams that finished badly last time could open up a decent gap we were hanging on, around 7th place or so. But the first driver complained about understeer and a car that was "slow".

For no apparent reason, nothing had changed except front tyres. Well maybe that's the issue...

Not much to do about that, other than to keep driving. I went out and could really feel that the front end was "un-settled" and soon decided to just get around as good as possible and try to keep out of trouble. We all did mostly just that and slowly won a spot here and there, mostly thanks to other teams making mistakes or getting into technical problems.

Already before the start we had spotted an engine mount that looked suspect and when I went out on my second stint I recognized the feeling from season 1 when the gearbox let go, because of ripped engine mounts. Trying to be nice to the car did no good for the lap times but we moved along, and towards the end of the race we were at least in 4th place.

Then the BMW in 3rd slowed and we could overtake them easily. In the lead, the two Opels (Astra and Kadett) were fighting a furious battle for the win. We, on the other hand, had two quicker cars chasing behind but they were laps down. When our 4th driver went out for the last time he took it almost painstakingly easy, but babied the car to the finish line. At this point it felt like the engine and left front wheel was about to fall off. But it all stayed in place, and we took the checkered flag in 3rd place!

Comparing lap times, our fastest this time was a 1.43.05 vs 1.42.33 last race, not that big of a difference perhaps but I have a feeling that the average is much slower. Maybe it's just that the others were faster, the winner and second place car both did 128 laps this time, we had 125, the same number as last time when we won.

I have not looked at the RaceChrono data yet to confirm. But blaming the car might not be entirely fair!

Still, it needs a decent amount of attention now. Next race isn't until mid August, and we need to decide if we're gonna get the new car running or continue with this one. The results so far puts us at second place in the totals so we don't want to gamble too much for race 3. But what is the biggest gamble - an old car that might break down or a new, untested car that might not be sorted?

Anyway, the GoPro recorded. All 4 hours in fact but I give you less than 40 minutes :-)

https://youtu.be/lMt2NTNV130

Gustaf

Good read Gustaf, glad you guys are still racing this season even if it's not with the new car. Do you think you'll switch to the p11 for next race? 

I have a question about your brake cooling solution. I bought some silicone hose to build ducting and came to the same conclusion... It's way too tight to fit a hose even close to the rotor. So it looks like I'll be making a deflector similar to what you've made. Any advice? How has it worked out? Thanks! 

I commented on the brake ducting somewhat in your thread.

TBH, we have not noticed more wear with no ducts on the pads we use now, the ST43's.

As for the P11...next year! The head is still at the machine shop and the engine is still in a million pieces. We're gonna have to focus on keeping the P10 alive for the remaining 3 races.

Gustaf

That's good to hear about the pads.  I found the st43's, and I was unaware they made them for this car. Does your Primera have the same brakes as our US G20? It's a 257mm rotor. 

What sort of speeds do you guys reach in your series?

Probably better to finish out the season with the car that's running. Winter is a better time for that big of a project. 

Good luck at your next race Gustaf!

The Euro P10 does not have the same front pads as the G20 - apparently the G20 uses the same calipers we got on the Primera station wagons. We had our pads made to order by Frozen Rotors. 

The current track has a top speed of around 141-143 km/h, around 87 mph, so speeds are rather low (a necessity with the temporary track arrangement).

Gustaf

The P10 has gotten a little bit of attention the last days.

First step was making a list of what to fix - engine mounts, exhaust flex joint, a burst CV joint boot and checkup on brakes and tyres.

We fitted new engine mounts back in 2015/16 when we swapped the broken transmission, and filled the mounts with windscreen glue. But now the rear mount had failed completely.

With new mounts on back order we had to try repairing these. We had found some 2-pack polyurethane or similar at one of the team members work places that we were allowed to try. So we filled all mounts up again and will hope for the best.

The CV joint boot really put up a fight since the removal process in the workshop manual described something else...but in the end, robbing parts from a bad drive shaft off the P11 we got it done. Now we are waiting for the motor mounts to set, before we put them back in.

The exhaust is also fixed so we are actually quite close to being ready.

Gustaf

The filled mounts are back in the car. Only problem is that the two first ones have not really set - seems the two-pack mix was incorrect. We had one of those mounts new (for the P11), so we're using that. Good thing is that those are the mounts that seem to hold up the best (fitted to the head and gearbox). The other ones, to stop the engine rocking forwards/backwards, seem to take more of a beating.

We have some tyres to rotate and check the gearbox oil level, then we're reasonably race ready.

As a bonus we had the time to clear out the boxes of stuff we bring with us to the track. Now we are down to one large "scuba box" with oil, some panic fix items and stuff. Earlier we had that one filled to the max plus three smaller plastic boxes, and a cardboard box...and... ;-)

Gustaf

Race report #3 2018

Armed with "solid" (ish) engine mounts, new front tires (215/40-17) we started the third race for this year. Quite far back, courtesy of our third place finish the last time. 

Now, the video is not downloaded and might not ever be, it seems the GoPro sort of froze but I need to check. So most of this is from memory. But our 13th grid spot meant we had some way up to go and I think we made the first driver change in place number 10 or something like that. The outstanding Opels soon made it to the front of the pack and then there were a whole bunch of reasonably fast cars following.

It is obvious - the teams that used to be mid pack and quite easy to pass have almost uniformingly improved. There are few "easy targets" out there for us now.

Our drivers quickly started reporting a slipping clutch, again - something that has been an issue for a long time. More about that later. Otherwise the car felt OK but not blindingly fast. 

We have also started to have some drive change issues, we used to be quick but now we fumble. More practice is needed here.

Still we worked our way up the field, in some cases based on speed, in other cases thanks to other peoples mistakes.

I had a rather tough first stint, didn't feel really fast and I had two BMWs that nudged me from behind before I had to let them go. The tricky thing is that our car (or I perhaps) was faster than them on something like 45-50% of the track, they were faster in the other sections. But my fast sections were also the parts where it is easier to pass and also easier to point someone by. 

Still we made most of the race with no bad mistakes, no real contact, no offs and no encounters with the track markers.

My last stint felt better but was slower :-( 

As the end was approaching we had a 5th spot, being chased from behind by 3 BMWs with a 4th one in front of us. A small hope was lit when Mayflower (the one we were chasing) got a Stop & go penalty but it was not enough, we took the checkered flag as number 5.

Once again, we are quite satisfied with the position in a car that we feel is "slow". Once again, the analysis of lap times show that it's not our team that is getting slower, it's the other teams that are going faster.

The other top 5 or so have improved their best laps by 1-2 seconds between race #1 and this race - we have improved by 0,1 second. Now, you really should compare mean times but the number of laps is quite telling. The winner (Skelleftereklam, Opel Kadett 16v) did 130 laps this time.  We did 127, still two more than the first race though. 13th spot did 119 laps. It is tight, after 4 hours in 500$ cars... The same 119 would have given 5th in the first race.

I am concerned about our clutch because the same thing repeats itself. It slips on 2nd-3rd shifts after 20-30 minutes of racing. Then we baby it a little bit, for something like an hour, and then it seems to work for the rest of the race. Is it because we continue to baby it? I really want to take it apart to see how the clutch disc and cover looks but the work is not fun.

Also, we are a bit short on options. Ideally I think I would like a good stock cover and a disc with an uprated organic lining. There are some kits available but not locally, and not cheap. We have a new kit for the P11, but this one started slipping quite early. OTOH it has been on the car since 2016 and made 13 races now...

We also should work on the spring rates and I have some options and ideas there. The question is, do we dare try the advised rates, around 400 lbs/inch front and 320 lbs/inch rear? That is probably in the range on 3-4 times the stiffness we run now.

Gustaf

Yesterday night we took the gearbox down, always a challenge in a car that has traction on the wrong wheels!

Our bonded engine mount has failed again, the sleeve is loose. I suppose the two-pack polyurethane didn't really have time to set.

After much cursing, bending and forgetting inaccessible bolts, the gearbox came down and we could investigate the clutch issue. At first glance, the clutch cover looks OK, no real signs of heavy slipping. The friction material on the disc also looks quite normal.

However.

The disc is cracked! Two fully formed cracks, one hairline and the 4th is probably just waiting to let go.

Now, I don't think this is the cause of the slipping, rather that a slipping clutch may have overheated the disc. There are also a couple of fingers on the cover that seems to be bent.

We trial fitted the P11 clutch set we have and it seems to fit just fine so we will use that. The broken one above is a Valeo kit, the new one is a Sachs (with a LUK branded disc). I have used Valeo parts before with no ill effects but still rate Sachs a bit higher. So here's hoping...

Quite happy that we bit the bullet and removed the gearbox because when the disc would have let go for real, that would have been the end of that race.

I also prepared a bit for solid mounting the front subframe, I have an idea that might just work. We'll see.

Gustaf

Nice work Gustaf!

Bummer that the field is getting faster, but good for you guys for hanging in there.  I think that your team is punching above its weight because you've been able to run a clean race, which is just as important (if not more) as being fast. 

I've also heard that primeras should have much stiffer springs, so I'm curious to see how your spring selection works out.  My first thought is that you've raced the car in the rain.  It also rains here about 50% of the time that I'm at the track.  Softer springs should be better to help the suspension roll a bit when there's low grip.  Ideally you could have different spring rates for dry vs wet racing... but hey this is budget racing! Ain't nobody got time for that!

Good catch on that clutch disk