Alpine GTA Turbo - V8 Europa Cup Style New Project

[Tony Smith]

As this is my third GTA project after my Safrane Biturbo engined black car and my 2.9i silver car, I think I'm going to call it Project G4P (Glutton for Punishment.) It's something I have considered for a few years and I had dismissed it to be honest. But then I got offered a cheap GTA Turbo which would have probably sat in my garage as a spares car. But a chance discussion with my very good friend Steve Dell who runs the RAOC changed my mind. He rents half his unit in Bicester to a small 2 man band classic car restorers who have been putting LS3s into Jensen Interceptors. They had been doing a bit of work on Alpines for club members and said they really liked the idea of putting one in a GTA. Turns out the all alloy Chevy lump is only a couple of inches longer than a PRV and if you add on the weight of the turbo is actually no heavy than the PRV.
Work is underway with the original engine and suspension already removed.


Car seems very solid with just one rear turret needing a small amount of welding, although they haven't got to the other area of worry to check for corrosion in the box section where the steering rack lives.
Most of the glass is ok which is a relief as is very hard and expensive to source now.
All suspension etc all removed front and rear



Most of the stripping is now done mechanically and any making good will be done over the next couple of weeks as the parts are assembled for the new V8 subframe.




So plan is to build up a new rear transaxle with new and spare parts I have, that bolts straight in as per original so that the car can be swapped back to original if required. Spare subframe back from shot blasters.



These are getting bought next week.

LS3 is Corvette spec 430bhp and the other pic is all the stuff to run it.

 

[Chris Smith]

@Neal R19 project thread here....

Looks like it's going to be an impressive one

 

[Neal R19]

Aww yeah, this is going to be good

 

[andybond]

What is the block weight difference between OEM and LSx ?

 

[DaveL485]

As Mr Burns would say....

Excellent.

 

[Gary]

Look forward to this build

 

[Tony Smith]

What is the block weight difference between OEM and LSx ?

Not sure, I only looked at overall weight.

 

[Adey]

the increase in power will surely negate any increase in weight? especially with the jump its going to have

 

[Big Steve - Raider]

FOOOOOOOOOOOOK that should be epic!! Great soundtrack as well!

 

[Tony Smith]

the increase in power will surely negate any increase in weight? especially with the jump its going to have

There is no weight increase, the turbo, intercooling and extra plumbing offset the weight of the extra 2 cylinders. Engine is rated at 430bhp in a Corvette so should be at least that. Projected weight with some sort of cage is 1250-1300 kg. So well over 300bhp per ton.

 

[Duncan Grier]

Very nice.......s/c it as well

DG

 

[Tony Smith]

Ordered the engine and ECU yesterday. The lower spec one was on a 6week delivery but they had the next one up in stock so bit the bullet and bought that. Only problem is I'll definitely have to uprate the gearbox now :0(.
This one is being spec of the one being delivered tomorrow.

The Hot Cam Adds Heat to the LS3

Our engineers never stop tinkering. When they took a production LS3 6.2L (376 cubic inches) engine and swapped the stock camshaft for the racing-inspired LS Hot Cam (P/N 88958753), the result was a stunning 495 horsepower and 473 lb-ft of torque.

We wasted no time in adding that terrific combination – dubbed LS376/480 – to our crate engine portfolio. The key to the power boost is the Hot Cam’s 0.525-inch lift on both the intake and exhaust sides, along with 219-degree/228-degree duration specs. That’s


less lift on the intake side than the stock LS3 cam, but considerably more duration, allowing the valves to stay open a little longer to draw in more air from the rectangular-port L92-style heads.

Use the LS376/480 with a controller kit (P/N 1925267), which includes a special pedal for use with the engine’s electronically controlled throttle.

 

[Adey]

this will actually be a monster, cant wait to see it progress

 

[DaveL485]

My mate runs an LS lump in his Ultima and had some heat control issues, i'll put you in touch if you like.

This is it now Zircotec plasma coat on £4.5k's worth of manifolds. Yummy.

 

[Duncan Grier]

Different setup but the Audi tfsi S3 engine I put in the vx220 needed careful air flow and heat protection

Had a customer wanting to cut coats with the non zircotec option

Not long after, original option agreed

This and some decent quality heat reflective materials has no issues at all on road / track

That is some exhaust Dave!

 

[Tony Smith]

Exhaust set up is one of the things worrying me, getting it quiet enough to use on circuit could be hard. Going to use the standard manifolds if I can so shouldn't give off as much heat as the tubular ones. Also a heavily vented back plastic screen should help and no engine cover. Also a fair bit more space around the engine. The original turbo lump gets very hot so hoping it may be better :0)

 

[Duncan Grier]

You could always use 2 turbo's to reduce the noise

Std manifold a good call Imo, n/a can be noisy things. The old zetec lump in the race car on carbs could not visit most circuits. S14 turbo lump in there and even Bedford would welcome it

Looking forward to seeing this one Tony

DG

 

[Tony Smith]

This weeks update.
Prep work mainly. Rear turrets were pretty good just needed 1 small hole patching.





Front bulkhead, another notorious rust spot, nothing serious just a bit crusty





Major alarm system to be stripped out. Bodged with scotchlocks :0(


Should be all cleaned up ready for new shiny bits by the end of next week. Also going to have some strengthening of the rear subframe and mounting points done to cope with 475 ft/lbs..

 

[DaveL485]

That wiring reminds me of Amrits disaster! Like that but 10x over.

 

[Tony Smith]

Power plant has arrived and is no bigger in anyway than the PRV :0). Going round in circles with gearbox decisions this week, ending up with the more powerful lump means there is very little chance of the UN1 lasting long without serious modification. Had decided to go with the Audi transaxle box but then found out it has a fixed diff so cant be turned round to run rear engined like a UN1 can. You can't believe how many versions of the UN1 box there have been. They reckon the best ones are the A610 box or the Lotus V8 later the better. So have to decide whether to buy a second hand one of these , or rebuild one of my UN1s with a better diff and uprated main shaft coupling. These 2 options are still extremely marginal and will probably require me visiting church everytime I put my foot down. So that leaves me the expensive option of an off the shelf 6 speed 'box which will cost me more than the engine or rebuilding a UN1 with Quaife single piece shaft kit and LSD. You cannot believe how much these parts are. £2500 for the shaft and gears !!
Any of the clever people on here know anyway I could strengthen the spline coupling. Could it be welded? Also are new 2 piece splines still available from Renault as I'm told spline wear is a big contributor to the sleeve failing. Would it be possible to copy the 2 piece splines in a stronger material , possibly with a cut of spline that has more torque resistance?