GT-Forte GTs40 build

[David]

Thanks to HRH and her little party I had a free day today.

After lots of practising, finally welded something other than a test piece and made up some engine mounts.

(really should have pictured both of them but nevermind)

Tragically ran out of gas (need to get a proper bottle rather than the disposable one I started with). So I need to 'close' the box and weld the captive nut in but I can at least fit the engine.

Now just need to make up the gearbox mounts.

 

[Darrin]

Been over a month since the last update. Was hoping you might let us know how those Hartwell brackets ended up working out for you. Know you needed to buy the end link part for one.

Also, I am wondering how you plan to do the interior with our kits having a full roll cage. Are you planning to cover the roll bars?

Seems like the interior of most cars doesn't really match the exterior in it's completeness and adding roll bars probably doesn't help it any.

 

[David]

Ha, I've not done anything much in the last month. Real life getting in the way again.

Anyway, I've been thinking about the rear bulkhead, there is on the GTs40 (same tbh as others) a 'step' between the centre section and the sides. This doesn't match the originals which are flat. Other people have used marine ply to 'fill' this section up to the same level. I think I'm going to get some aluminium square tube to raise the outside sections to the same height and then panel across it. Haven't then decided if I'll make it out of one large piece or three.

 

[David]

I've not done anything with the latches yet, nowhere near that stage.

The roll cage does make life trickier, I don't think I'll be hiding it but will be covering it in foam anywhere there is a chance of coming into contact with it.

 

[David]

Although not done a lot I have done a little bit.
Decided I was going to copy others and make the section at the bottom of the screen in aluminium.

Also don't think I posted a picture of my oil take off block

I may have gone slightly overkill on the AN-10 fittings given the restriction in the middle but we'll see.

Also have started working on ITB's.

Mocked up here with a couple of throttle bodies (that tragically don't fit)

I just need to get hold of a proper set of throttle bodies.

Not sure how many updates I'll be posting for the next few months. I've got a new job, significantly more money but an earlier start so won't have as much time to work on the car and will have to cut down on the GT40 funding for a bit until I'm settled.

 

[Thurston Kent]

Hi David,

I have just read your build log start to finish, it makes for good reading

Anyway I thought I would chime in here as you may not be aware. I believe there is a company selling a manifold to bolt on two sets of quad throttle bodies from Toyota 20 valve 'silvertop' 4AGE engines to the 1uzfe. Sadly I don't recall the company, but I believe they were based in NewZealand. A google may reveal the answer if this is somthing you're interested in.

Keep up the good work.
Thurston.

EDIT: I just found the site http://www.a1turbos.co.nz/.

 

[David]

Hi Thurstan,

Yes I found those, unfortunately they'll set me back ~£1500, plus postage plus VAT and import duty, figure £2000 all in. A set of motorcycle throttle bodies will set me back ~£2-300 (£3-600 at trying it on breaker prices) plus making the adapters myself will cost ~£60-100. While I'm not strictly speaking on an overall budget (I'm running it on a monthly spend basis) the more money I spend the longer it'll take!

I was admittedly hoping to run the original manifold, ecu etc and upgrade when I'd got the car on the road. I ran into issues with the distributors fouling on the rear firewall however and as changing from them effectively required a new ECU decided f**k it, lets go straight to how I want it so it's straight to ITB's and COP with an aftermarket ECU.

 

[Darrin]

What size Cleco pins did you use? 1/8"? 3/32? I think with 4mm holes the 3/32 would be too big?

 

[Jayson]

I use 4mm darrin.

 

[David]

Sorry, forgot to respond. 5/32 or a smidge under 4mm.

You can get them a *lot* cheaper in the US but shipping is a bitch. I got mine from LAS Aerospace in the end.

Ideally you should drill undersize, use undersize cleco's (relative to the rivets you plan on using) then when you are happy finalise with a final drill to size, de-swarf/de-burr and then rivet.

 

[Darrin]

Thanks to both of you!

Will get 50 5/32 Cleco pins. Those are no problem.

Now to try to find 4mm x 9.5mm aluminum sealed rivets in the US! LOL

 

[Bill Musarra]

Try McMaster Carr
McMaster-Carr

Bill

 

[David]

Starting to think about how things are going to go in the cockpit, ages ago got a SPF or CAV pedal box

The only issue (apart from weight) is that it doesn't fit far enough to the right.
So a bit of modification is required...

Bzzzzzzzzt

I'll have to sort out some new bolt locations but now it can sit with the brake pedal central under the steering column.

Even if I do panel the inside of the cockpit I may have to leave that section to the right unpanelled, not exactly a lot of room in there. I may even have to buy some driving shoes!

Had of course to try it out so introducing for the first time the Cardboard seat!

(any rumours that I sat there for a good 30minutes pretending to drive it while making V8 noises are totally unfounded )

 

[David]

Picked up a set of GSXR1000K2 throttle bodies, 50mm converging to 42mm and I think 240cc/min injectors. 8 42mm throttle bodies should be good for up to 811hp, although 8 240cc/min injectors are only good for ~300hp according to MegaSquirt-3 Fuel system

This does mean if I want more than 300hp I'm either going to have to change the injectors (probably to Honda S2000 [390cc/min] or CBR1100XX [335cc/min]) or bump up the fuel pressure. Replacement Injectors We'll take that as it comes though.

One of the reasons I picked these is that they're easily separated and re-spaced, that included the fuel rail as the individual injector sections are just linked with short bits of aluminium tube, very easy to just turn up a couple of longer pieces.

Anyway, two issues with the throttle bodies, first being that GSXR's of that era have dual throttle plates, one controlled by computer, the other by the rider. The idea being to act like a CV carb so that if you whack the throttle open suddenly the computer controlled plate (relatively) slowly opens to keep the airflow smooth and prevents jerky throttle behaviour. Trouble is that even if I wanted to keep it there are three stumbling blocks, firstly my ECU wouldn't know what to do with them, second the servo motor for them won't fit (the water bridge gets in the way) and finally as they are linked in pairs and the TB spacing has to change the rod won't fit so out they come.

First job therefore is to blank off the shaft holes for the secondary butterflies, turned up some top-hats, a bit of sealant on them and press them into place.

Here as a comparison I've done the one on the right but not the one on the left.

Next problem is the spacing, as they came from a 1l and they're going onto (effectively) a 2l they need to be spaced rather wide. This is roughly how they will be spaced, not sure if you can make it out but the manifold to head gasket is sitting underneath them.

Should be easy, just turn up a few spacers (I'll make 2 of each so I have them for the other side when I buy that) and then turn up some pipe for the fuel rail (again 2 of each).

Downside is have no 12mm bar atm and don't really fancy turning down some 3/4in so have to wait now for some more deliveries. Bah.

 

[jyrki sulka]

Calculation shows maximum hp with 8 x 240 cc injectors is 330 hp in n/a engine, then duty cycle is 80%. Can`t use more % with MS3 (or any ecu).

 

[David]

Long time no updates. Not a lot has gone on as been busy with work and family stuff but a few updates.

Firstly I have a second set of TB's along with all the bar I need to space them.

Secondly I have a radiator.

 

[Jon Briggs]

That looks like a nice bit of kit. Where did you get it from, and any idea on price? Always like to know about new places for parts.

 

[Jayson]

Is that one of the winner racing units Dave?

 

[David]

Yes, one of the winner racing ones, total price was £225 inc VAT and the parcel farce thieving scum charge.

 

[David]

Quite a few purchases recently, not many to shout about (unless people are really interested in random bits of metal!) a couple worth mentioning though.

First off a bit of bling in a remote oil filter

Not cheap but not expensive either considering how much the Mocal ones are.

Then a pair of radiator fans.

I've done a bit of work on the car but nothing worth taking pictures of!