Brands Data Logging + Bypass Cooling

Tim and I use the same data loggers and analog inputs so that we can share our data for comparison purposes. Tim had put together some graphs for comparison between us. My Laptime is 59.xx his was 54. and some change. He's in a class C car with some 40 less horsepower too so lets see where those 6 seconds went. (I'm blue he's the black trace)

Click on the graphic to see a more detailed version.

The answer to where did those six seconds went is simply "everywhere" and at a uniform rate. The bottom trace "timeslip" shows my rate of time loss relative to Tim's lap. It's an even uniform line that shows I'm not bad in one particular spot but simply slower everywhere. The speed trace confirms this in that on average I'm 10-15mph slower than Tim everywhere except in Graham Hill Bend where I'm slightly faster. Interestingly I'm pretty much on the throttle everywhere before Tim is and I brake harder and later than he does. This i guess is a function of not being on the limit of grip like he is.

The top chart is corner radius which shows how tight we are turning and the traces are very similar so I'm not way out of position or driving the track in an odd way. I'm just a bit slower in ever corner and at every apex. The reason for this is shown in the G circle, this particular one is Druids and it shows that I'm not working the tyres at anything like the limit of their grip. Tim by contrast is nicely tracing the edge of the G circle as he transitions from straight line speed and converts longitudinal braking grip into lateral turning grip uniformly and evenly.

Basically if the tyres will give you 2G of grip you should be using it all for maximum braking and turning at all points through the corner. Although the Brake vs Turn proportion will change through the corner. Initally you start using all the grip for braking and will get full longitusinal brake G and then go to full Turn G and use all the grip for turning. I do each seperately Tim plainly transitions nicely between the two states using all the available grip at every point as his G curve traces a rough circle around the line that denotes the limit of grip.

It also shows that I'm largely back to my old habits of braking in a straight line before turning rather than turning and braking together into corners ( the Majority of the trace is moving along the Axis)

Of most concern is Tim's ability to out accelerate me out of Clearways . He thinks my engine is underpowered. Personally I think I'm overweight. When I analyse the corresponding RPM traces the problem is clear. On average I'm 2000 RPM lower in the rev range than Tim is pretty much everywhere on the track. Therefore I'm always at least one and possibly two gears to high, this is killing the engine's ability to rev and hence I'm accelerating slower.

So lots of things to work on here, Brake into corners, carry more apex speed, push the tyres and rev the nuts off the thing, change up later and change down further on the run in to corners to get the right exit gear. No more mechanical sympathy!

But with the thing cooking even when I'm effectively short shifting, revving the nuts of it is not an option until I resolve the over heating problems.

However I am in the process of fitting an oil cooler, plus I have an idea about the water cooling. I suspect that a fair proportion of the coolant is simply passing from the thermostat housing on the exit from the cylinder head and returning directly to the water pump on the side of the engine via the bypass hose (remember I've removed the thermost). The bypass is quite large bore and the pump will be applying a degree of suction to it as it connects on the input side of the pump. A good deal of the coolant is simply cycling through the the head, the pump and the bypass getting hotter all the time. At no stage is it going through the radiator and simply being re heated in the cylinder head with the corresponding problems controlling the temperature as only part of the coolant is actually being cooled by the radiator. So I'm going to clamp off the bypass hose for the next Meeting at Mallory and see what happens.

Testing and "Racing" at Brands

Not a great weekend, no major damage, but generally a bit disheartening in how slow I
was but the car held together with only a few teething problems. Of most concern is it’s lack of straight line speed relative to a much less powerful car (Judy’s) I think it is just too damn heavy and with less power now there is simply nowhere to hide.

As a result I’ve decided to cease developmental effort on this chassis and contemplate building a new lightweight one over the winter. In the mean time I intend to drive this one to death. Plus I need to lose some flab… but that’s obvious


On the plus side, car is smooth and pretty well balanced, the new brakes work and it is not displaying any nasty habits or snap oversteer in fact the only adjustment change I made all weekend was to knock a single click off the front dampers to kill a bit of understeer in Clearways. And my manual alignment was within 20 minutes of arc of being perfect. Plus the RGB paddock is full of great people.

Friday Testing.
I arrived Thursday night, Tim and I had arranged to share a garage so I unloaded and parked the car up in the garage. Tim was already fettling, so I took the opportunity to do a few extra things like stick on the CAM7 stickers. Tim and I got to sleep around 2 am and where up with the lark, or at least with Brands noisy indigenous bird population anyway.

I managed three test sessions on Friday, The first was a 6 lap shakedown, taking it easy and just seeing how things went. Pretty early on it became apparent that the cooling was crap. Even taking it easy oil temps were climbing to 120 and water towards 100. Not good and on reflection there is something seriously wrong here.

However I came in to check it over and see how things were. The only major issues were that the chain had stretched, and the shift lights were not working. So after giving it the once over and a brief stint to cool down, I went out again and gave it some beans. In about 6 laps I managed a 59.59 (front runners are in the 52s) but the coolant went to 120 and the oil to 140. So I decided to do a couple of laps touring round to cool it. but just then they red flagged the session so I had to bring a cooking engine straight in. Of course when you kill the engine the coolant pump stops and it immediately boiled over. Later inspection also showed that the radiator was also weeping a bit from one for the pressure margins where the metal and plastics are crimped together so the pressure had got just a bit too high and things are getting pretty hot.

After mopping the coolant from the garage floor, giving it a couple of hours over lunch to cool down, refilling it and fixing the rad. I thought I'd go out and do 4- 6lap bursts to get some value from the day. Again it over heated badly in the afternoon so I didn't get to do much, and my data logger failed to record any times either.

On the last session I bought it in and it was sounding like a bucket of bolts and only running on three. Really carp. I thought I'd badly cooked it. However Andy Bates came and looked at it and identified a stick coil that had jumped from the plug... and a couple of missing nuts on the exhaust manifold. Once these were repaired it sounded ok. But I decided not to risk it further.

However I wanted to fix the cooling issue before the race on Sunday so a quick call to Tim Pell indicated that there was a larger radiator that I could fit so I ordered one of these (from a 2Ltr Meastro Turbos Diesel) on the way home and collected the new radiator on Saturday morning. I then spent14 hours on Saturday fitting the new rad, cutting a vent hole in the front bodywork, making the aluminium shrouding to duct the radiator exhaust air out through the hole and fitting an auxiliary electric coolant pump. All in an attempt to get some heat out of the engine. I also refitted the electric coolant pump so that I could keep the cooling system running after shutting down the engine.


Duncan arrived around 5pm and identified an even bigger problem.
The Diff has twisted sideways under drive tension from the chain (this was what was allowing the chain to slacken)and the bolt heads holding the drive sprocket had started chewing into the steel shear plate at the rear, so he spent a few hours making a burly steel support to stop this happening. All in all we finished around 10pm. Essentially the tension under load is pulling the driven sprocket forwards. As the left mounting plate prevents the left mount from moving forward what is actually happening is that the right hand mount is moving backwards and the rear end of the diff moves to the left as the whole thing pivots around the left hand mount.So I need to stop this happening using different tension fittings on the mountings.

On Sunday I was up at 5:30, Dunc arrived at 6 and we reloaded the car on the trailer and set off once again for Brands, hopeful that we had fixed the problems.

I arrived in the paddock to much congratulations for actually making it to a circuit and some gentle ribbing, but it was nicely balanced with some genuine admiration for the neatness of the engine installation and some nice "Welcome Back" hand shakes from the RGB paddock. It was really very very nice to be in the paddock again. In fact sometimes it was hard to get to car to stick the stickers on it because everybody was stopping by for a gawp and a chat :-)

The car passed scrutineering first time, and so it was on to practice. Somehow I arrived early and ended up fourth in the queue. Once the session started my over heating problems seemed to be a bit better, I was running at about 1:05 deg water.... dunno what the oil was as I hadn't managed to load the updated software from Tim onto the palm on Saturday and it crashed on lap one, driving Round Brands... resetting a plam pilot will definitely put a kink in your times. :-)

So after 6 laps and with the whole field streaming past me (not a good sign) and the coolant running towards 110 again I decided to call it a day and come in.

The qualifying times came in and I was dead last. 59.6 I think, which is 1.1 second down on my fastest time from last year, but then I did have the kwacker.

In between practice and the race we tested the engine and were concerned to see that the secondary injectors were not firing, so we spent a couple of hours chasing down the fault. But it wasn't a fault, it was a ghost. Everything checked out and eventually when we re tested them by stamping on the throttle rather than winding it up gently they worked fine. So they are not the reason I was slow. I'm slow because I'm slower than a slow thing out for a Sunday stroll pushing his infirm slow granny in a slow thing's bathchair!

When race time came I was lined up on the grid dead last with Judy in her class C Fury next to me, when the lights went out, she got the jump on me and we were off. At Paddock I briefly thought about diving up the inside but wasn't really close enough and on the way to Druids passed Gordon G's stricken car in the gravel on the left. Round Druids and there were two other RGBs spinning into the ARMCO on the left and so unsurprisingly the race was red flagged while they cleared up the carnage. On the restart we made it as far as Clearways on Lap 2 before we found a spinner in the gravel and we had earned ourselves another red flag plus a group bollocking from the Clark and retirement to the end of the meeting. The Observers reports used words like "disgraceful" pretty bad stuff. Apparently people were still banging into each other when the red flags were waving but I was too far back to see it or be involved.

So as the last race of the day we restarted and this time I managed to hang on to Judy for a couple of laps and was actually trying to go up the inside of her at Clearways when I missed the selection from 2nd to 3rd. By the time I had found a cog she was 100 yards up the road and I went down the straight swearing loudly. Difficulty selecting the right gear for Clearways was to be a recurring theme and marred the rest of the day (such as it was) . In fact I suspect in frustration I yanked the lever a bit hard as I seem to have bent it! I hope I haven't damaged the gearbox selector forks. If not then Mr Honda's engineering really is bullet proof.

Although I felt I was getting faster in Paddock, Surtees and Mcleans, Druids and Clearways remained crap. Particularly Clearways which is the crucial corner for Brands. After about 8 laps and having been lapped the temps started to climb again so I abandoned it and headed for the paddock. Once there I discovered a stone hole in the nice new radiator that had done precisely 15 laps. :-(

So the take home messages are

1. It needs an oil cooler, I think the oil is currently heating the coolant through Mr Hondas standard oil\water heat exchanger and for some reason I can't keep the water cool. Either that or I need a wire basket to cook my chips in the boiling oil.
2. I'm slow, dog slow.... glacial in fact
3. The engine seems to be pretty strong in terms of standing up to abuse.
4. Most of the work this winter seems to be wasted as the power loss certainly isn't counteracted by the weight loss.
5. Last year I was plainly using the power of the kwacker on the straights to mask my crap cornering. with less power now there is nowhere to hide.
   Must get better!
   Hmmph

Final Pre Race Setup before Testing

Well the final week before the Test at Brands passed pretty quickly and as usual I never got to do the everything on my to do list. For years I've been making lists about the car to make sure I don't forget stuff and in this respect (as my wife pointed out) I'm like my Mum. We've never visited her without finding an old envelope and a pencil on her kitchen counter with a list of things to on it. I guess there are things you learn at your mothers knee that you don't even realise. On the subject of lists I also learned from Tim that the categorisation that I tend to do for my lists is actually known as a MoSCoW list. Which is Must do (IE critical), Should Do (preferable but not essential), Could do (if enough time) and Would do (in an Ideal world).

Most of the last Saturday before the test was taken up with wheel alignment and general chassis setup. I'd never done this before from scratch and so again following Tim's advice I gave it a go. Starting with ride height, then wheel camber, then front and rear toe in, then front\rear alignment and finally corner weights.

This whole process took all day and necessitated the construction of a few adhoc tools. One of these was a combined alignment \ride height gauge made out of a piece of angle Ali angle and an up stand. The gauge is actually 83 mm tall so that when I sit in the car the resultant suspension squish drops the car to the regulated 75mm (which is about the best approach when doing it on your own.) On the back of the gauge was a graduated scale which I used to check alignment. Basically I stuck a magnetic laser level on each rear wheel and held the gauge on the front wheel and then adjusted the rear toe control until the pointers hit the same mark on the scale when it was held on the front wheels. Then with the laser on the front wheels and the gauge on the back this gives me fore\aft wheel alignment around the centre line of the chassis. Then when adjusting toe in if you move each side the same amount of turns the alignment should be maintained as you dial in the settings.

I also made a toe in gauge, which is basically a long U of steel so that you can measure the relative distance between the front and rear of each pair of wheels. The method was to position the bolt head on the wheel rim on one side of the car and then use a set of digital calipers to measure through a hole in the steel to the rim on the other side of the car. Zero the digital caliper in that position. If you then move the gauge to the front of the wheels and re measure you can directly read the toe in value off the calipers.

I was aiming for toe in of about 1.5mm at the front and parallel or a very tiny amount of toe in at the rear. It took me all day and by the end of it I was far from certain that I'd got it right. but it seemed ok

So the complete set of alignment settings were

Front ride Height 83mm

Rear Height 95 mm

Front Camber 1 3/4 deg

Rear Camber 3/4 deg

Rear Toe in - parallel

Front Toe in - 1.5mm

Front Dampers 8 Clicks

Rear Dampers 10 Clicks

Tyre pressure 18.5 psi all round

Unfortunately I didn't have time to do the corner weights, so I still don't know what the ultimate weight saving is from stepping down to Class B and changing the engine

So after 6 months of gestation it was time to take this new engine, diff and chassis combination to the track and see what it could do.

More progress to report :-)

First up I completed the wiring for the new rainlight that is now required by this year's regulations, OOOOh look a glowing set of LEDS that look almost identical to the last set of glowing LEDS that were fitted there. You'll have spotted a pattern that most of my jobs are now the little things that are requried to meet the RGB series regulations. This is a good sign as it means that I am now focusing on the smaller jobs rather than major structural or mechanical components, ERGO I'm getting to the end of this.

Next it was on to that leaky front Calliper. A quick test on Tuesday night indicated that both the left and right calipers were leaking when under heavy pedal pressure. Both from the same place; where the top halves of the caliper are joined by the removable aluminium spacer. If you remember the picture of the handbrake calipers this is where the fluid cross over drillings are located and the two sides are pressure sealed by a rubber O ring. I suspected that the O rings had aged and failed and a call to Hi-Spec confirmed that this can happen. So a couple of rebuild kits were duly ordered and should be here for the weekend. That will mean I need to disassemble the calipers which in turn means I'll need to bleed the brakes ....again!. Shouldn't be any bubbles in my fluid. No sir!.

The other job identified last weekend was that the reverse control needed a control lever to get sufficient mechanical advantage. So I've quickly fabbed one up out of a strip of ali bar stock. This now makes operation of the reverse very easy. So easy in fact that I was concerned that the system would jump out of drive if knocked by my arm, so I fitted a retaining spring to the diff to hold it in the forward drive position. Of course this does mean that I'll have to manually hold it in the reverse position to actually go backwards, but this is preferable to false diff neutrals in a race, also it means it should slip in of it's own accord If I happen to miss the engagement dogs. Also as is my own particular habit I labelled it up clearly because it is slightly counter intuitive (pull back to go forward) but also because I forget stuff!

The other major system ( and the last to be done) that was completed this evening was the handbrake, having finally got calipers to fit I needed to connect them to the handbrake lever. This entailed welding a couple of mounting plates in the rear frame (next time I'll get these made up as part of the laser cut plates). And adjusting the sierra handbrake cable to fit. It took me a couple of attempts to get the routing tight so that the wires didn't get cooked on the exhaust but in the end we got there. And I now have a working hand brake..... well working good enough to pass scrutineering. :-)

The plates will need painting but this is hardly essential before Brands on the 20th.

Then came another regs job. All chain driven cars must have a chain guard fitted to stop the chain exiting upwards or rearwards if it snaps (and they do). So a few minutes were spent with some Ali angle and I got about 60% of this particular job complete. Other small jobs that got done in the evenings this week included torquing and staking the front hub nuts in place, replacing the DL1 sensor, fitting locknuts to the Diff spacer plates and lockwiring the diff and sump plugs.

The To-Do list now numbers just 22 items totalling about 14 hours in estimates and ranges from essential stuff like Set Toe In, Ride Height and corner weighting (4 hours) to the less vital .. check and adjust pedals for heel toe (10 mins) and fit race numbers (15 mins) and finally to the nice if time category including polishing the beast.

Nearly There!

Well over the last weekend I've got an awful lot done, which is good. but pressure of work means that I'll have to cancel my test at Mallory and test closer to the Brands meeting on the 20th, which is less good, although it does relieve some of the time pressure.

No 1 and most importantly I've finally got a complete and working braking system and managed to fit the new 14" alloys to all four wheels for the first time. The hassle necessary to get the various combinations of calipers, disks, offset, calliper mounts, spacers, 14" wheels, leaky master cylinders, alloy bells, rotors, suspension bolts heads and brake pads into a combination that allows the car to both move without the brakes\calipers\pads binding and stop properly when you push the middle pedal is simply incomprehensible. Take my advice If you ever..... ever EVER build any sort of racer or kit car choose one that uses standard uprights (the bits that hold the hub,bearings and calipers) and standard caliper mounts. Then you can choose a known, working off the shelf kit where somebody else has invested the necessary blood sweat and tears. If you have to fabricate or sort any of this part of the car out yourself be warned it is a seemingly endless trail of frustration and woe.

The latest in a long stream of issues was that the pad depth on my Mintex 1144 pads was too thick to fit across the new 9mm rotors, what this means is that you a) have to grind slightly one edge of the pad backing pad and b) reduce the thickness of the friction material a bit using a file simply to get the pads to fit over the disks and then to get them both to fit in the caliper slot. And this despite me ordering calipers with a slot specifically tailored for 9-12mm rotors. I chatted to Hi-spec about this and they said "yeah!.... we're having lots of trouble with the pad manufacturers altering either backing plate designs or pad depth..... file em to fit".

Bah filing pads every time I need to change them seems like a job I don't need.

Hmmp, anyway after an inordinate amount of frustrating tomfoolery (which also included me copiously testing my garage floor paint's immunity to brake fluid) everything was finally fitted and ready for bleeding. Bleeding the system identified a couple of leaking unions (one of which was on a master cylinder which then had to be replaced). But eventually we got there. And I finally have a working brake system. Due to replacing the master cylinders and cleaning the pedal in the last post I probably need to adjust the pedal rest position to allow me to heel and toe properly but compared to getting to this point that should be a doddle.

It was only later that I noticed a slight leak on the front left caliper that I'll need to investigate next week.

While I spent a "pleasurable" few hours sorting out the brakes Duncan was fitting the exhaust more permanently. Tony Law had done a good job of fitting it, but had failed to account for the fact that the Diff slides backwards when the chain is tensioned. As a result when the Diff was in it's final position the CV boot rubbed on the exhaust can. The solution was to cut off the existing slip tube which formed the exhaust joint, and add one about 3 inches longer. This allowed the Can to be positioned further back away from the CV joint. With this sorted out he then set about fitting an axillary support to both the can and rear body support frame. By his own admission he wasn't very pleased with either his welding or the fact that he designed the whole thing "in peel". Still it is at least sturdy enough for one or two races so I'm not going to worry about it now and as always I'm more than grateful for the help.

Other stuff that got done today or in the last few days included.
Torque the front hub nuts, finalise and tighten the gear linkage, tap and fit the new gear knob that Dave T had made for me, renew rear suspension Nylocks, flush the diff with petrol and fill with new gear oil. Lock wire diff drain plug, change a couple of CV joint boots, fit new brake lights connector and replace the temporary plastice cable ties with nice stainless steel ones. Tighten rear sprocket bolts, bolt check suspension and fit new calipers.

The other major piece of work that got done in the engine bay was to complete and fit the airbox. This required connection of the secondary fuel rail to the main one via a -4 bulkhead fitting and wiring the electrics via a suitable grommet. Plus I needed to make a new cover plate for the rear of the box. I made this out of clear perspex and finally got to discard one of the last vestiges of the fire... the old airbox cover.

So now the engine bay is complete bar one little job (I'm going to re route that fuel hose left on the which looks to be in peril from a flailing chain) I have to say I'm pretty proud of it. It looks neat and tidy and properly designed.

At the end of the day, Duncan got his just desserts and had the honour of driving the beast up and down the drive.

True to form this small test identified another little job, the reverse select T bat does not provide enough mechanical advantage to make selection reverse\forward easy and so this will need a lever fabricating.

The long list of Odds and Sods.

You know I can always tell when I'm getting towards the end of a build the engine bay starts to look like it has been visited by the NASA fairies, as I finalise the cable and fuel line routing and fit the shiny silver heat protection sleeving.
I got most of this work done on Sunday, and also did some preparatory work on the running the fuel and electrical lines from the main bank of injectors to those in the airbox in readiness for fitting it to the car.

In addition I fitted the catch tank, and bolted the exhaust headers, tightened up the gear linkage and did a few other bits and bobs jobs.

I've also dismantled, lubricated and rebuilt the brake pedal as it had got a bit stiff and recalcitrant about returning to the rest position. I wondered if the master cylinder springs were getting a bit weak and so disassembled the whole lot to clean, strip and check it. Ultimately it turned out to be binding in the pedal pivot point and the MCs were fine. This whole exercise took up a couple of hours and of course I need to re bleed the brakes again.

I'm currently working towards a shake down test at Mallory Park on the 9th May, and the plan is now to complete the build and setup the car over the bank holiday weekend, then go to the test, and then work on the Bus so that I can get it through it's MOT before I need it to go to Brands on the 20th.

Time will tell :-). but currently the planets do seem to be aligning for me at long last