Winter rebuild

Winter rebuild

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Discussion

sniff diesel

13,053 posts

170 months

Saturday 7th February 2009
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I know how hard it is working on cars semi-outdoors in this weather so fair doos for getting on with things Iain. Give us a shout when you're thinking of hiring the airfield as my 325i could do with shaking off a few cobwebs and bedding in some parts.

Chassis 33

Original Poster:

6,193 posts

240 months

Sunday 15th February 2009
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Hello again boys and girls, I'm still waiting on the body, still waiting on my next contract too, I've been out of work since November! Anyway I've been cracking on with the wiring for the engine electrics which has got me thinking, I'm dangerous when I think. Anyway the long and the short of things is that the wiring loom I'm using as the basis of the engine electrics comes from a Disco II that I bought a bulk lot of bits from a number of years ago, loom sensors, manifolds etc etc. The engine I'm going to be building up originated in a P38 Range Rover and had a 36-1 trigger wheel fitted to the flex plate as standard. This got me thinking, instead of usinga trigger wheel mounted to the front pulley where it is exposed, ungainly (IMO) and fouls where I want to mount the alternator, was there some way of combining the P38 tigger wheel with a manual flywheel (manual P38's are rare as rocking horse teeth btw), so I can use the OEM crank position sensor seutp.

Anyway I popped over to the engine and drivetrain forum and bounced the idea around there, and after a lot of oooo you'll never get that to work etc a Griff owner came up with "I've thought of that, did all the work, but then I used a different engine so never used it", a quick journey to Stoke and a few beer tokens later I have this

A 2WD flywheel with a groove machined in it to accept the P38 trigger wheel, all I need to decide now is to weld, bolt or Loctite the ring to the flywheel...any suggestions? I'm thinking Loctite 380 may well be the best way to go.


The coil packs I'm using are also from a Disco II, and I'm mounting them onto the Disco manifold, this means that I wont be able to use the traditional trumpet base and plenum as the tracts are in different places. As you can see in the photo, I already have a Tufnol insulating plate for the manifold, what I intend to do with this is to create a trumpet base/lower plenum around the Tufnol spacer and bolt onto the top of this one of Tim Lamont's ACT Carbon Fibre Westfield plenums, with the throttle body (again 68mm Disco II) mounted at the front of the engine with a ram air effect from an intake in the new front end.

Thats it for now.
Regards
Iain

spend

12,581 posts

209 months

Sunday 15th February 2009
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Although I prefer the layout of the later inlet manifold, I can't see how you are going to get any flare in the tufnol. Will you be able to radius it somehow? a straight 38mm hole will perform like a lame duck I would imagine.

You will also lose all vacuum connections off the trumpet base so what you need will have to come from the plenum?

If you are planning on using the Bosch ECU (thor) I believe that has 60-2 trigger wheel on the fly BTW (as opposed to 36-1 with Sagem at least you confirmed that I wasn't sure if it was true..)

Chassis 33

Original Poster:

6,193 posts

240 months

Sunday 15th February 2009
quotequote all
The Tufnol can be worked as per any material, think of it as very hard MDF, so I could blend in an entry there, or I may have to mount trumpets to the base to regain the length lost in the hotwire trumpet base. Until I get on a rolling road I wont know but reducing down a set of trumpets and doing back to back runs every 5 or 10 mm isnt going to be difficult, albeit a little time consuming. The other option I have, that I've toyed with in the past is to run the rear section of the Thor rams head inlet and bolting a pair of throttle bodies to the front...kinda like...

2x68mm throttles give circa 500hp everything else being appropriate obviously, so more than plenty for my 300hp target, although having such large throttles may give bad manners around town, it shouldn't be an issue on a racer

The only vacuum connection I need is for the MAP sensor, and even then its arguable as to whether I need that on a racer, I'm not running a brake servo with the new pedal box, and obviously not running a dizzy so no need for vacuum advance. Although I do have a Thor ECU I'm going to be running Megasquirt, between Joo and Phil Ringwood I've got an ECU that offers everything I want for peanuts. I dont know about the trigger wheel for a Thor set up, however the P38 setup pictured is 36-1

Right I'm off to attempt to get drunk on Budwieser and stuff myself with nachos in time for Daytona.

Regards
Iain

HRG

72,790 posts

197 months

Sunday 15th February 2009
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I'd be very interested in hearing what you end up doing with the geo and if the numbers will translate to the standard wishbones...

TVRleigh_BBWR

6,547 posts

171 months

Sunday 15th February 2009
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Trigger wheel is look like it's fitted in well.
only concern is hopfull it's not weak'nd the flywheel too much. as the shop I asked to do mine said he did not want to take that much metal off.

also how much lower is the thor plem, compared to std one.
Also you could allways mount the coil packs on the bulk head, and use any plem. you want.


Also on the Emerald you don't need a MAP sensor, ideally you need a Air temp sensor, but this is not 100% needed either. so can't see why the mega squirt should be different.

Nice to see it making progress though.

Chassis 33

Original Poster:

6,193 posts

240 months

Sunday 15th February 2009
quotequote all
On MS, you can map directly against engine speed and TPS with corrections for temperature like you have done with the Emerald, or map MAP vs TPS and engine speed. Both work ok on a racer, so long as you dont have massive altitude variations eg pikes peak, arguably MAP vs gives a more refined setup for better low speed manners.

Regards
Iain

Chassis 33

Original Poster:

6,193 posts

240 months

Thursday 19th February 2009
quotequote all
Hello again, since my last post I've been exploring the Thor inlet some more, an I've found some interesting (well to me anyway) bits out about the inlet. Firstly all the inlet tracts from manifold face back to the opening are as far as I can make out the same length, the second and possibly more useful bit on information that I hadn't clocked in the past is that the tracts are arranged in such a fashion that neither mini-plenum has two consecutive cylinders drawing air from it at any one time. Well that's not strictly true because you'll get an amount of overlap but most importantly you don't get 5 & 7 fighting against each other for air. The reason for this is that the front and rear pair of tracts on each bank loop back and feed the cylinder they sit above, however the middle pair of tracts cross over and feed the opposite cylinder...does that make sense...?

Anyway for the time being I'm going to pursue this option to see where it leads me, my next hurdle is creating adaptors from the round throttle bodies to the rectangular Thor inlet as you can see in one of the earlier pictures. To do this I'm going to make a pair of adaptors out of glass fibre. I went to my local garden centre and bought one of those Oasis blocks for flower arranging, they cost £1 each for something about 12in long and er brick shaped...
From this I found a glass tumbler that was the same Id as the Id of the exit of the throttle body..approx 69mm, and pressed it into the end of 1/3rd of the Oasis block. I marked the other up as an appropriate size to the rectangle then took a large kitchen knife and sculptured two of these, they take about 10mins each

and wrapped them in parcelling tape (I checked and the glassfibre the resin doesn't stick to the parcelling tape)

then cut four 100mm squares from MDF to make a former for the mating faces, also a few short lenghts of coat hanger wire to hold everything together...

so putting things together I have this...

My next challenge is to figure out how to make the two mating faces stay parallel to eachother while I lay up the glass fibre, then it will be a case of hand fettleing the bores to remove the kinks etc.

Regards
Iain

TVRleigh_BBWR

6,547 posts

171 months

Friday 20th February 2009
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Why can you get a 1/8" ali plate, cut it to the same size as the Thor TB. and drill a hole the size as the TB. and also drill holes for mounting/
you could then place this onto the plenum and mark the mounting points on the plate.

mount the plate on the plenum, and use a small grinder to merge the hole of the plate to the plenum hole. then bolt the lot together with some holimier.

if you want a longer blend, you may want to get some ali tube 93mm, cut out 4 slots out of one end so you can blend it down. and then get 2 ali plates welded to the ends.

3rd option would be slimar to the above but the ali tube would be a bit long and cut in the middle and use a silicone hump joiner, so you have some flex.

I think the Glass fibre ones you are making are maybe too long and also may not be strong enough. or are they just going to be inserts, it hard to judge the size.

you may also want to think about using Carbon fibre not glass its not that much more expensive, plus you still use it the same way.

GreenV8S

28,427 posts

242 months

Friday 20th February 2009
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Is the cross section area the same at both ends? You want to keep it constant area if at all possible, or else gradually blend the change. (Reducing the area is OK, increasing it not so good.)

Looking back at your rose jointed suspension you have the axis horizontal for all of them. Rose joints don't like axial loads and I think your braking forces are going to make them unhappy.

Chassis 33

Original Poster:

6,193 posts

240 months

Friday 20th February 2009
quotequote all
Leigh the adaptors are approx 4" long and I'd argue that 5mm of glassfibre (the depth of the returns for the flanges) will be stronger than 3mm of ali, and less likely to fatigue. As you can see from the photo of the two gaskets below, a decent length is going to be needed to get a blend between the two x-sections which is why I've gone for an adaptor peice instead of a blended plate.


Peter, all good points. The X-section is going from approx 36cm^2 down to approx 30cm^2 so a shade under 20%, over a 4in loft its a fairly smooth affair.
WRT to the rose joints, its something I've queried in the past...the Malaysian Chim racers had their rosejoints with a vertical mounting bolt, however Tuscan racers have it horizontal, as per a standard bush arrangement, the vertical arrangement is the stonger design and something im looking into.

Regards
Iain

TVRleigh_BBWR

6,547 posts

171 months

Friday 20th February 2009
quotequote all
Chassis 33 said:
Leigh the adaptors are approx 4" long and I'd argue that 5mm of glassfibre (the depth of the returns for the flanges) will be stronger than 3mm of ali, and less likely to fatigue. As you can see from the photo of the two gaskets below, a decent length is going to be needed to get a blend between the two x-sections which is why I've gone for an adaptor piece instead of a blended plate.

Regards
Iain
Fair points, did not know there was that much of a difference, it's prob. due to normally 1 TB supplying the 2 tracks, where you are using one each. be interesting to see the result.

spend

12,581 posts

209 months

Friday 20th February 2009
quotequote all
Surely the majority of braking loads will be trying to twist the wishbones, so the joints orientation seems sensible to me. The static situation with a locked wheel forcing backwards to the advantage of horizontal orientation would be the exception rather than the rule I would have thought?

Chassis 33

Original Poster:

6,193 posts

240 months

Monday 23rd February 2009
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Not much of an update but I've the first spyshot of the new nose...

Hopefully you can see that, if not I'll host the photo elsewhere.

Regards
Iain

TVRleigh_BBWR

6,547 posts

171 months

Friday 6th March 2009
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Any more news you got the body yet.

Chassis 33

Original Poster:

6,193 posts

240 months

Friday 13th March 2009
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Hi, right I've been away from computerdom for the past fortnight. Have I missed anything? What I do have are some photos of when I went to Kidderminster to have a bit of a tyre kick regarding the body. The previous photo was effectively the buck that the front end mould was taken from. The mould now looks something like this


When it's all back together the lights will be faired in as per the run-out edition and have the Lupo light conversion, just to freshen up the existing design without going down the "Speed Six" route.

The roof is going to take its basis from the Tuscan Challenge cars, you can spot one the glassfibre guys had knocking about from a previous project, however it will be modified to create something of a fast back to help reduce the aerodrag commonally associated with the notch-back design, I'll then be using an underbody venturi and an end mounted single plane blunt nose aerofoil (read functional spoiler not a chavtastic Halfords affair) to balance the aero created by the front splitter and dam

Regards
Iain

Barkychoc

7,848 posts

162 months

Friday 13th March 2009
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Instead of parcel tape use self amalgamating tape - its a rubbery compound and you won't get the creases in it.
You'll get a small step as you build up the layers but I reckon you could sand that away on your final fibreglass creation, though you may not even need to.

Edited by Barkychoc on Friday 13th March 17:51

Chassis 33

Original Poster:

6,193 posts

240 months

Wednesday 11th November 2009
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Holy thread ressurection Batman!!!
The Chim has been put on hold recently mainly due to the length of time its taken to get the main body back, but also cos I've changed jobs moved house etc etc all those horrible things you do when you become a grown up which stop you from doing what you want to do which is playing with cars. Anyway, I'm promised the body back this weekend and by way of a teaser...


Regards
Iai

TVRleigh_BBWR

6,547 posts

171 months

Thursday 12th November 2009
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Looks different, with that top, have to see it IRL to make a real judgement, but glad you back working on the car, hopefully you be out for the 2010 Season.

Chassis 33

Original Poster:

6,193 posts

240 months

Wednesday 8th September 2010
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Afternoon folks, this thread is likely to have more come backs than Rocky Balboa!

Just to say since the last post I've moved house (again) found myself a decent workshop, some spare cash and intend to crack on with the Chimaera as soon as possible. I'll try and keep you posted

Regards
Iain

Edited by Chassis 33 on Wednesday 8th September 13:22