My Lexus Isupra Conversion

[vinokirk]

Hi bud, cant belive i found this thread just after posting a new thread about putting a Supra engine in an IS! Ihave been banned from driving for 6 months and was going too sell the Lexus but just the other day was wondering how hard it would be too fit another engine in it. I will PM you.

[Pip]

Fantastic mate. I wish i was able to do something like this.

[DeanoC]

Just read the whole thing. Amazing!!

[gsportcars]

Latest update....

I finally recieved my stainless steel welding wire so I can now start into the exhaust side of things.

First up I had to modify the inlet pipe for the wastegate from the manifold. As shown previously when the wastegate was fitted the outlet from the wastegate was pointing directly at the steering knuckle joint.

I have had to extend the inlet pipe coming from the manifold so that the outlet now sits below the steering joint. I also had to bend and twist the pipe to get the wastegate at the correct angle.

Please forgive the dodgy looking welding as I had to fill out the pipe to 2" instead of 1.5".

I have also started to heat wrap the manifold to keep things as cool as possible in the engine bay. here it is half complete as i need to get some more stainless cable ties to do the rest. This is a nightmare of a job as the wrap is primarily made of fibreglass so it makes you itch all over!!! The wrap I have used is also graphite impregnated so my hand were black aswell when I was done. I am still itchy now

Here is the manifold with the wastegate in its new position

couple of pics of the manifold with heat wrap in the engine bay

Here are a few pics of the new wastegate pipe that now clears the steering joint

I am starting on the downpipe next before I finally fit the engine for the last time.

update to follow.

[Adie]

Well done Gav, keep it up mate :D

Are you heat wrapping the whole manifold? I'm leaving mine so as the heat can disperse and so the manifold doesn't crack. This was something that bothered me for a while because I still dont know whether its best to wrap the manifold or not

[Monster-Mat]

its best to wrap the manifold, having a wrapped manifold reduces under bonnet temps, but will also stabilise the heat up and cool down of the manifold

reducing the potential for cracked manifolds

the worst manifolds for cracking are stainless steel, as in the polished type, most peeps use

[Adie]

its best to wrap the manifold, having a wrapped manifold reduces under bonnet temps, but will also stabilise the heat up and cool down of the manifold

reducing the potential for cracked manifolds

the worst manifolds for cracking are stainless steel, as in the polished type, most peeps use

Thanks Mat :)

[gsportcars]

Yes mate as Mat says, get it wrapped up tight.

I am also worried about my manifold cracking under the weight of the turbo etc when it is red hot which is why I am fitting some strengthening braces from underneath to hold the manifold steady.

A couple of small sections of stainless rod from an engine mount bolt to the underside of the manifold should do nicely.

I am also heat wrapping most of the exhaust aswell.

[Adie]

Yeah I'm doing the same for the manifold for strengthening off the engine mount.

[gsportcars]

Started my down pipe from the turbo.

I can now remove the engine for th last time to make the small brace for the manifold and do some other small jobs before fitting the engine for good.

I have decided to go ahead and make up a twin exit exhaust system. i was toying with the idea but though I would have to in order to do the engine swap justice :D

The part I was most concerned about was fabricating the section of exhaust to split the single 3" pipe into 2 x 2.5" pipes. I had heard that it can be a night mare to do.

This is the section of 3" pipe that I cut angles out of.

After a lot of trimming and squeezing etc etc of pipes I managed to get them to match up fairly well....at least I thought I did. I am no welder, I just bought a welder to do this project after trying it out on a friends welder. The main problem after considering all the curves and angles that need to be right is the fact that I am joining two pieces of pipe that are 1/2" smaller in diameter to the one single piece

The welds look quite messy but as i underestimated how precise the joins needed to be i had to fill a lot of gaps and holes with weld. This is prob the only time anyone will ver see it though so I'm not that worried

[Monster-Mat]

could have had my twins, im moving back to a single

possibly even sill exit

Gav, did you manage to get the ID of the lower coolant pipe.....

Edited December 8, 2006 by Monster-Mat

[gsportcars]

Ahh...didn't realise you were going single with the exhaust mate or I would have.

I have already got the bits for doing mine already unfortunately

Sent you a text yesterday mate.

anyway it was 34mm inner diameter and 35mm outer diameter put I could only measure it with a tape measure. Oh and those measurements are for the metal water inlet pipe on the engine.

[TheDon]

Forgot to say that your 1.5mm thick wheel spacers are ready...

Need your adress if possible fella

[chrisis200]

I love the babies bib...lol

I may have to get one for myself in prep for Xmas drinking etc ;)

Oh & the car looks like it's coming along nicely mate, thanks for the updates... as u say i'm sure ur extremely busy now days :)

[gsportcars]

Latest update guys.

I have made up a small support bracket for the manifold that supports it from underneath. Just two small rods that bolt up to the engine mount. I didn't want to have brackets on top of the manifold as it looks bad IMO. This support is out of sight.

I also finished heat wrapping the manifold and this time I used some laytex gloves :D .

I have finished my downpipe and simply need to weld on a flexible flange and then start on the rest of the exhaust.

I have also fitted the engine, gearbox, prop shaft and gear shifter for the last time. they are now staying there.

I just have some tidying up of wires to do and to fit the radiator, viscious fan and I am waiting on a fan cowling coming to me also.

It is a nice feeling being on the home stretch but also a nerve racking one

[RoadRash]

WOW..... what A/R do that turbocharger have??

1.04 or something?

[gsportcars]

It is .60 A/R.

The exhaust housing is much bigger than the compressor housing. Should still get 500bhp fairly easily though.

[marcus]

Looking very nice gav :winky: can not wait to see this up and running

[gsportcars]

I didn't get much done to the car over the christmas period as expected but I have recieved my fan cowling for the viscious fan. Sourced from a TT supra that a guy was breaking on eBay.

Although I don't have any pics I had some modifications to do to the fan cowling. It originally had two holes, one for the viscious fan and one for the aircon fan. As I didn't fit the aircon pump I needed to cover up the second hole which I did with a section of aluminium plate simply cut to fit and screwed over the hole.

The mounting points on the IS radiator are different than the supra rad too so I used large washers to clamp the housing onto the rad. A few bits needed trimming to allow the cowling to sit fush with the radiator.

Here is a pic of the fan cowling in place

I had to cut out a small section to allow for the top rad pipe which was also previously shortened.

Each of the fan blades as Matt mentioned to me before needed trimming down. This was because the fan cowling is now positioned closer to the engine as the IS engine bay is not as long as the supra one and everything is closer together. here are a couple of pics taken of the trimmed blades in place behind the cowling.

I have also made up the exhaust section from the down pipe back to about the rear diff where the exhaust splits into 2 x 2.5" pipes. This is for the twin exit exhaust. I have welded in a flex to the down pipe and am just waiting on a flange coming in the post to join the two exhaust sections.

As I want the two back boxes to exit the car at a slight angle similar to the HKS dragger and prolex kazama I will need to do some more mods to the spare wheel well. It does not allow room for the second exhaust box to be mounted at an angle so I will have to cut out a piece from the passenger side of the wheel well to make some room. I will then weld in another plate section to seal up the boot etc.

Pics to follow as usual :D

[RoadRash]

its best to wrap the manifold, having a wrapped manifold reduces under bonnet temps, but will also stabilise the heat up and cool down of the manifold

reducing the potential for cracked manifolds

the worst manifolds for cracking are stainless steel, as in the polished type, most peeps use

...and not to forget: Heat wrap raises exhaust gas temp. which raises exhaust gas speed,

for better spool up.

Who knows physics will know, that the hotter gases are, the thinner they are so the quicker they can flow.

:winky:

Same on exhaust system..... a too big diameter in exhaust system can reduce power instead of

raise it.

Exhaust gases can cool down because of the lower speed in a large diameter ex.sys.

and cooled down gases reduce speed and can block the gas flow. ;)

[gsportcars]

OOhhhh very technical!!! LOL

But good to know these little facts.

[gsportcars]

Not got much done with this the whole of January but I decided I had to get a move on and finish the project.

Here is what I have been doing the last couple of nights

I finished my exhaust finally.

Here is the down pipe with the heat wrap on and finally fitted

I have some pics of the full exhaust finished and heat wrapped before I fitted it to the car but they are on another camera at the minute so I will post them later.

As mentioned before I had to cut away a section of the spare wheel well to allow me to position the second box at an angle instead of being straight on. Apart from giving better flow due to less bends in the exhaust I wanted it like this because I personally think it looks a lot better.

Here are a couple of dark pictures as it was 1am when I finished it....

And a couple of day light pics...

I also made up an air intake so I could fit my air filter

And here is an engine bay pic with everything but the intercooler pipe on the intake manifold present..

I have been trying to source some aluminium bends to do my intercooler piping but I have only been messed about by the few people who can supply them. As i want the car finished asap I am going to make the intercooler piping from stainless steel for now. There are no real disadvantages to this apart from an extra bit of weight but the difference is not really that much. I will probably re-make it all with alu in the near future.

Unfortunately I am still awaiting my new front bumper from the states but it should be here any time now. Once the intercooler piping is complete I will start to concentrate on getting the car running incase there are any teething probs when we turn over the engine for the first time

Anyway updates will follow as usual......

[marcus]

looking very nice gav, can not wait to hear the sound of that exhaust looks good the way you have it as well.

gav you can get intercooler pipe/work kits of eBay and just cut weld to customise it to fit :winky:

[aido]

As ever, it's awesome mate!

Can't wait to see see what she's like when she's all done, a very, very impressive conversion you've done there mate :)

Good luck on firing her up, bet you can't wait!

[Adie]

Nice one Gav. Looking great mate :D