My GTA Turbo Project

Maybe Martin, when you thinking about it?

I should be going on the 27th, but if that doesn't work, I can arrange another slot anyway so don't worry too much. I've got to get the P4 on soon too, I was hoping that would be next Friday, but Chris (owner) can't make it , so another date will follow soon enough

Cheers,
Martin

Martin,
Ring me to confirm suitable dates post Croix, happy to help out in the name of science haha.
Dave

[stephendell]

Why not run them both down south. Much closer for everyone and you can invite Mr Smith too for a proper head to head!

Why not run them both down south. Much closer for everyone and you can invite Mr Smith too for a proper head to head!

Because we'd never hear the results ..It'd all be kept close t'chest

.
To do that we would need to organise an appropriate event, but if you are only looking at it as a head-to-head then you are missing most of the value of actually doing it - no two setups are alike, choices made on the compromise to suit each owns values, desired application, and budget etc.. They all have their merrits, and these can easily be ignored missing the more subtle big picture.. Moreover very few times do we actually get together as a club / collective talent to look at what we have critically with focus of gaining the best from what ever the hartdware may be. I said as much about making the Brunt sessions into more about ensuring collectively through the body of knowledge our car setups both power and handling are optimal.
As to RR and location, then the choice is simple as I see it, back to Peter's. I'm building a fair amount of Bhp data on the rolls there now, we have tested JIL at various stages, F50 likewise, JV's present and F43 RTP before it, Darren's, Teglen's, Will's a couple of times I think. It is easy to fall into trap of comparing dyno against dyno figures, and multiple sources of data, I would rather keep a known constant, and then any improvements and changes are valid data, so I'm sticking to one establishment now.

If more constructive focus, all pitch in and get the best overall performance per vehicle, then I think that would a great day, quite a full one though. Further, I'm sure Will, and Cedric would be interested in joining if conducted at an appropriate time, as would Simon Taylor.

Anyway, that's my view..

Cheers,
Martin

Sorry only just seen all this- for some reason didn't come up in the new posts for me.

Anyway- I'm a musician not a mechanic so i'll leave all the subtle nuances of volumetric efficiency to those that know!

I just wanted to add that the curve shown here was very surprising at the time. Martin and I had been working on the car until daybreak the night before and frankly I don't think either or us thought the car would get to the RR let alone post anything like a decent figure. As Martin says there were no goals set other than to get there and back with a working car!

To that end however it meant the mapping that was done was aimed at the top end to make sure we weren't causing damage to the engine. Having driven the car for some months now it became clear that more time was needed on the bottom end and mid range as Martin had always suggested.

This work has now been done and the boost turned down to 20psi and the car is now in a different league from a drivers point of view. Lag has been all but eliminated and it just pulls and pulls. No flat spots and the power feels even more linear. It also revs faster to the redline and sounds much smoother.

As I say I'm not a mechanic but I would suspect that the next graph whilst not producing any new figures in terms of headlines will most certainly find a different spread of power. Ok the subject of engine revs- I maybe wrong but don't all turbo engines run less revs than there atmo counterparts? I'm thinking Ferrari 458 vs MC12-C etc

Anyway I would agree that the amount of knowledge being spread around is a good thing and would hope that with this knowledge we as a group of owners move our cars forward.

Here's to the first 400 bhp GTA!!!

[BIG_MVS]

How about a good old fashioned RWYB day at Santa Pod or Shakespear Raceway? I'd be up for coming along to watch as I'm sure quite a few others would be too?

[stephendell]

I said as much about making the Brunt sessions into more about ensuring collectively through the body of knowledge our car setups both power and handling are optimal.

Sadly, we haven't been since the runway has been fixed.

There is still time to go before the end of the season if the demand is there and a few people are up for it, otherwise next year.

No delete on this thread... just moved my posts around for house keeping I'll be doing the hoovering next as well soon..

Thanks,
Martin

.. the housing is also designed to provide containment if the turbine were to let go, and this one wasn't going to do much in that way, I know I wouldn't want my head by it...

If in doubt:

http://www.youtube.com/watch?feature=pl ... Y01Ed4Sg3U

Good video of Garrett containment tests from many years ago and you will see the energy levels involved, a cracked housing is more likely to look more like the one below in that kind of event, and they do occur... I have a shaft that the turbine was about to do this, the housing contained the event prior it letting go.. I don't take it lightly..





Food for thought...
Martin

Its a hard one to gauge but I bet it will be less than I think :0). Original engine (internally standard) but with fueling and intercooling sorted used to make 240-250 bhp at 1.1 bar. My 3 litre makes about 315-320 at 1.1 bar with a T38 blower. The most efficient turbo engines make about 140-150 per litre at a bar of boost (with a sensibly sized turbo). So my logic is going to say your cams and other mods have improved volumetric efficiency by say 15-20% so I'm going to guess about 1.7 bar or thereabouts to net 350bhp. It would be interesting to get another GTA on those rollers for a comparative figure though or a 1/4 mile terminal speed. Don't like to be sceptical but figures vary so much from RR to RR. A friend of mine has a MK 1 Escort with an Atmo Cossie tuned to the hilt and he has seen 40bhp difference (220-260bhp) on different rollers. An exceptional result regardless :0).

Hi Tony,

Sorry late reply, spot on and like your approach, thanks for sharing.

Did you catch this, a while back now, asked in my Bones thread (page 10):

http://www.renaultalpineownersclub.com/ ... r&start=75

Page 6 Tony's post, is your T38 turbo fitted with the RS500 compressor wheel, Garrett part number 409535-0007 Exducer 76mm inducer 56mm?

Have I identified the right compressor, or do you have the smaller version? Easy check, if you could get a measure of the ID of the turbo inlet on the parallel section just before the blades, be great if you can confirm as I'm currently doing a hybrid with this compressor wheel

Thanks,
Martin

I said as much about making the Brunt sessions into more about ensuring collectively through the body of knowledge our car setups both power and handling are optimal.

Sadly, we haven't been since the runway has been fixed.

There is still time to go before the end of the season if the demand is there and a few people are up for it, otherwise next year.

Just seen the new runway on east mids news ...some blind dude setting world record ...Looks a lot better now .

.
Hey Jon, you are famous... or infamous, dependent whose perspective

To quote Le Journal issue no. 56, nice article by John Sweet: Origine RS - Renault Sport Day, Goodwood 2014:

"There was also a rather shabby looking black GTA going round, I spotted a charge cooler on top of the engine during one of its visits to the paddock, I don't know who owns it but under its unremarkable exterior there is some serious horsepower lurking - and whoever was driving it was making a very good job of deploying it on the circuit."

Hey, Jon, we all think you are a right tool Laugh!

Cheers,
Martin

[BIG_MVS]

What's the crack Martin, have you joined CAR now?

As for the driver I reckon it was Jon's mate (who reminded me of the fella below, in fact at first I thought it was actually him).

Ha Ha!!! Always loved a bit of shabby chic.

Glad to see that circuit lesson was put to good use anyway....