Project Scimitar MV6

[lozzzzzz]

This evening I faffed on, I love "pottering" round the garage! I changed the oil, which took a while, I didn't give oil changing much thought really when I routed the oil cooler hoses tightly round the oil filter, and mounted the LPG solenoids right over the oil filler. Anyway its got some jazzy race oil in now.

And I checked the wheel wobble over lots tonight. The rims are definately true, I tried the space saver wheel and that ran true, the back of the rims also turn perfectly true (that was scary!). It must be the tires. Got a show on saturday so I'll leave it till next week to go make a fuss.

Here are some pics of the show last weekend.















I took the car to PPC in the Park, and it was a great show, for me it was the best that PPC in the Park has been. There was a jet power push bike, the record winning 80mph mobility scooter, a crazy monocycle thing, the 27l meteor engine on home made engine dyno, and an excellent mix of cars. Sorry about the odd selection of photos, I was a little bias

More to come

[lozzzzzz]

Ummmmm PAS is so nice. Glad I've got it now, it should make the autotest a lot easier tomorrow if I have a go.

Well here it is ready for its 3rd show:


More to come

[lozzzzzz]

I took the car to the Modified Nationals yesterday with my friend Peter of Capri fame. My car stood out like a saw thumb, as it didn't have any speakers in it and was very old compared to everything else! But it was a good day, the Scim actually got lots of attention, being so different from the rest of the cars there. Pete and I did the auto test right before I left, where both cars got lots of attention. It was just a car park with some cones, but I really enjoyed it. It was the first time I've driven the car against a clock and squealed the tires, was lots of fun, needless to say I didn't do very well

I think the fastest time on the day was 21 something and my best time was 23.10. But I had lots of fun.

As I was saying goodbye to everyone an onlooker approached and very kindly offered to send me a video he took, I'm very grateful, here it is.
http://www.youtube.com/watch?v=WlDtRi5W0P4&fea...

On another note, the PAS really has transformed the car, Its a different beasty all together, apart from the noise it is a lot easier to drive on long journeys now and there is still plenty of feedback. I thoroughly enjoyed the car yesterday and can't wait to drive it again.

More to come

Edited by lozzzzzz on Sunday 26th May 09:01

[lozzzzzz]

Happy birthday Rodders, hope you have a good day.

I'll post the times up here, and hopefully a video too if I can get one of my buddies to do one or two.

[lozzzzzz]

What uprated cams? Yeah there are some available from courtney sport, but they are a lot of money, I think £350 ish. This info comes from the owners forum but: I understand the oil gets very hot when revved hard and can cause bearing problems, I've got a massive oil cooler, but I think my preferred route will be to supercharge the 3.2 (forged crank) engine rather than over revving this one with Cams.

Maybe next years project

[lozzzzzz]

Hi folks, I had an awesome day today I took the Scimitar to Santa Pod to try my hand at drag racing. I certainly haven't put the car together with this kind of thing in mind, but thought it would be a great way to enjoy the car till the bank recovers and I can get it finished for a track day. But I had a lot of fun today, it was fantastic and I think I might go again some time.

I managed the following times:

13.9274
13.8746
13.8738
13.9403
13.8120
13.8066

I'm so proud of the car, two hours there, lots of burn outs and drag runs and 2.5 hours back (got lost). The car took a full day of abuse in its stride, performed consistantly, was fast and fun.

I was hoping to Challenge my buddy, but his 400hp Capri was just out of reach, athough only by 0.5s and I totally had him in the first 1/8th mile so I was happy with that having only a measly 260hp. A cracking day had by all!!!!

More to come

[lozzzzzz]

Finally found the loose screw in the camera and got it working again

Here are the pics










There we have it, my arse whooping

[lozzzzzz]

Thanks Rodders

I can sort of see your point, the Chome wheels do look awesome on the Capri, in fact I very nearly bought the same set when he did. I did a lots of "microsoft Paint action" trying different wheels on the car, and I'm pretty happy with my choice. I'm not going to risk doing it in case it comes out a bit too bling!

Me and Pete could always swap wheels for a bit and see how it looks, I know he's interested in trying some decent tires.

[lozzzzzz]

You got it, Just for show, I think he bought the centre caps from Summit and the spinners separately and put them together. I think one of the next things on the list is to get his rear wheels more outboard, they are really quite far into the arches at the moment.

He used a scimitar Axle from an SE5 with some wheel spacers, but when one snapped off, he thought it might be time to get some better ones.

[lozzzzzz]

I had it Mapped at Maynards and it seemed the engine was producing 262hp on their dyno, with 200 ft.lb at just 2000rpm and 250ft.lb higher up.

I'm still thinking about Nitrous, but the only purpose would be to try and beat Mr Capri, which I think it a bit of a silly as I could easily have him on a track day. I'm not sure yet, I guess it depend how I'm feeling when I next have a load of money burning a hole in my account.

The original plan was to supercharge it when all the teething problems are sorted. It is a lovely balance of performance and being useable at the moment so I'm still thinking it through.

[lozzzzzz]

A long overdue update.

I've done pretty much half my annual mileage in the car already!!! And the exhaust is doing my head in, Its not leaving the garage again till this is done! I'll be fitting a 1/4 wavelength resonator pipe to each side, with a sliding joint so it can be tuned to the right frequency then depending on the how that is I'm still thinking about pursuing the intercom route.

The other thing is bump steer, hands up who saw that coming after my new wishbones and uprights

Well I knew there was an issue from the start, you simply can't make a ball joint conversion without there being one. In a ball joint the steering axis and the axis through the end of the wishbone coincide and they do not in the trunion so I knew I would have to lengthen the track rods to take this into account. I've done all the calcs for this and found they need to be about 6mm longer each side. This is easily done with the steering arms being bolted to the uprights with great big spacers, simply turn the spacers down a bit

But what I hadn't though about was that I've make the upright about 45mm taller!!!!! The end of wishbone axis sits 45mm lower than in the original set up, compared to the top ball joint! This makes the 6mm track rod problem look like nothing. You can see this extra height in the following photos.




So after much calculating and trig and so on..... (and the race and rally source book, which is excellent for this sort of thing)


My options are......

• Raise the rack by 16mm and move it back by 3mm and extend the track arms by 6mm
• Lower the track rod ends by 20mm and extend the track arms by 6mm
• shorten the uprights by as close to 45mm as possible and extend the track arms by 6mm

My thinking is, instead of getting further into trouble, I'll take the option that gets the suspension close to the original and choose option 3.

More to come..

[lozzzzzz]

This afternoon has been an education. I'd done a lot of reading and trig to figure out what I needed to change about the suspension to get rid of the bump steer. I did it all on one side only so I could test both and see the results. The results from the left and right sides both looked the same

I was just raising the suspension and watching it though, so I devised a more accurate way of measuring the bump steer. I used the laser from my tracking kit and attached it to the upright in various ways and marked off the path it followed through the suspension travel. I made sure the laser was always pointing perpendicular to the side of the car no matter what the steering angle was and put the target the same distance away each time etc.

I've been messing about with it for hours and have finally figure out what is actually causing it to bump steer. I've lengthened the track arms by 6mm, not a bit of difference. shortened the upright from pivot to pivot by 45mm down to the normal 290mm ish, not a bit of difference, still lots of bump steer. I sat looking at it for hours then thought about adjusting the caster angle, that made a big difference and I managed to get the staight line you see in the last photo on the right.




So it seems the issue of bump steer is very sensitve to changes in caster (resulting in changes in the height of the track rod end relative to the rack), and not very sensative to track arm length.

There is still lots to do in deciding the best place for everything, but I feel like I'm making a bit opf progress and might actually solve it now.

More to come

[lozzzzzz]

Thanks Rodders

I'm working on the tractor at the moment, but the Scimitar should get some attention again soon.

[lozzzzzz]

Oh right some decent progress today

I tried making up some spacers on the lathe, but ruined the last good edge of the last carbide tip and ruined the thing I was making



Then I asked someone at work to do it for me and he made some up really fast


Hopefully you can see, there is a tapped hole in each side of the block, the tread in the steering arm has been drilled out so with the offset of the hols in the block the steering arm is up at an angle.



Now, the bump steer is gone I'm waiting with baited breath to see how it feels (the spring rates are still unchanged so could be well out), but hopefully it'll behave a bit better.

I'm hoping to get that lot painted up and properly fitted tomorrow.

More to come

[lozzzzzz]

Today, I got it all ready for paint and put on lots of stone chip, but first I bent and welded a spanner to get at one of the PAS unions. They've all been nipped up so hopefully will stop leaking.


Its all back in place now.


Hopefully tomorrow I'll get it all tracked and.... camber'd! then start on the exhaust or intercom, depends what arrives first.

More to come

[lozzzzzz]

Got lots done today.

Got all the suspension back together, set ride height, checked camber, added a shim, checked camber, did tracking, set ride height again, checked tracking, made another adjustment, drove it, made another adjustment to tracking (to get steering wheel in right place) set (*******) ride height (again) checked camber (out on one side), (you've got to be joking) removed the (*******) shim. Its getting there, I've got to check the tracking again as the shim removal will have put it out. To give some kind of an explanation, I can't leave it "close" to what it should I have to get it completely right.

On another note, I got some cool bits through today, I got an Autocom Active-7-Smart as suggested by someone who has used one with a Caterham, and made up some ear defender type headsets. It works a treat, I'm pretty happy with them



I'm hopefully tackling the 2100rpm exhaust drone tomorrow.

More to come

[lozzzzzz]

I thought I'd take a slightly better photo of the intercom thingy which is working well


On the exhaust front, I thought I'd make a 1.4 wavelength resonator pipe for each side, but the materials came to quite a bit of money so being a skin flint, I thought I'd try a balance pipe. The theory being that the two pipes should be completely out of phase and perhaps have a cancelling effect (fingers crossed). Here are a few pics:





And guess what......






After all that work........





It made no difference, there is still a 2100 "Drone Zone" perhaps its 2% quieter or perhaps its in my head, or perhaps my hearing is gradually getting damaged. Either way, I'll be ripping back off and trying the more expensive 1/4 wavelength resonator pipe option soon

More to come

[lozzzzzz]

I completely forgot to say, the alterations to the front suspension have worked really well, I'm very pleased. The measured bump steer seems to completely agree with how the car feels. This has now highlighted the next weak link in the suspension.

The rear axle seems to spend a lot of time in the air when going over very rough patches of road, the back seems to step out a bit when on the power in a corner. I think this is a combination of things really and just needs correctly setting up. But it doesn't help that the axle is even heavier now, the disc conversion probably weighs more than the drums and the Quaife Differential definitely weighs quite a bit more than the open diff, on top of that the spring rates could be way out, calculating those is next on the list, and the I think I might have got the dampers turned up too much delaying the axles return to the road on rebound.

More to come on that lot.

[lozzzzzz]

I've experimented with side exit exhausts. I'm not mad keen on the look, but I think it looks alright if its done well. My thinking here was that it would alter the length of the pipes and therefore raise the natural frequency right up the rev range where it wouldn't be annoying in traffic. But there was no room for the second silencer, it was far to exposed and will hit speed bumps. I tried without it, but its ridiculously loud at all RPMs then. So I binned the idea and shall simply be living it for a while. After driving it round a little more with balance pipe on, I think it has made a difference, it wasn't just me hearing things, the resonance is a little less. I wonder now whether its to do with the natural frequency of the cab!!?!?

I got the Intercom into the dash yesterday, by recycling a Peugeot Stereo. I reduced the depth of the box, and put a new fascia on it as you can see in the pictures.







Its not perfect (but that's in keeping with the rest of the car )

I'm off down the garage to continue the road trip preparations.

More to come

[lozzzzzz]

I've just had it weighed! I'm a little disappointed with the total but very pleased with the balance. With me on board the front end is supporting 660kg and rear 620kg. GIVING A TOTAL OF 1200kg (without the 80kg driver). I think I was expecting it to be a little less having lost the Essex engine, but I have put a load of LPG gear in it.

These number were with the gas tank empty and the petrol tank at about 1/4.

THIS MAKES THE BALANCE 51.6% front, not bad at all

Next thing is to use the bathroom scales and try to weigh the unsprung weight, then do some calculations and get the right springs

More to come