Absolutely epic results here for one of Doug Stirlings escort cosworths!

Background was that it was a bit of an evolved spec over time, it had an NMS head and NMS cams on a Dave Pitchard built bottom end running on L8 and mapped by NMS on a GT3076 turbo on a .63 housing, made respectable power but Doug felt it was too laggy (TBH it wasnt *that* bad IMHO, you just needed to keep the revs up when driving it and it went well, and was still a massive leap forward from the old T4 it had before that anyway!).

Doug took it to Mark Shead at MAD and gave him carte blanche to change anything that he felt was appropriate with the aim of not losing top end power but gaining spool and responsiveness as that is what Doug is really into with his cars. Power before was tested at 480bhp IIRC (will try and get the graph off doug when I see him next or see if he can email me it)

Mark removed the water injection, ditched the cams in favour of some of his, fitted one of this new spec-r intercoolers and fitted a vipec ECU and remapped it with a GT3071.82 instead of a GT3076.63

Not only has it massively transformed the bottom end torque (at one point in the rev range IIRC it made 190lbft more than previous due to the earlier spool) its also gained power on top as well:


Here is the graph how it stands now:



It ties in now finally with how much power MAD get from the same turbo on an Evo engine as this is the first GT3071 they have done on a big spec head and latest specR intercooler, all their other 3071 conversions have been on more standard cars, giving around the 470bhp or so mark.

Interestingly Doug's engine is still low compression, 7.2:1 in fact, so the top end power could possibly edge up a little more form a raise in compression too.

Hopefully I'll get a chance to take it out for a spin on sunday if Doug has it with him when I see him, should be manic now on the 3.9 gearing as it felt pretty reasonable even before.




PS, when they tried edging the boost up to 2.7 bar, it made 522bhp and 520lb ft! but still tailed off to the same figures at the top end as the turbo just cant maintain the boost at high RPM as it really is flat out at that

 

very good for a 30/71

 

Some more spec from Doug:

Dave Pritchard built Engine, 2 litre Mahle pistons WRC h/gasket, 7.2:1 comp ratio, NMS flowed head, hydraulic lifters.
Siemens 900cc injectors
Small turbo plenum with 10mm spacer
MAD modifications:
Latest type Spec-R compact Garrett cored intercooler
NO water injection (removed from car)
Latest MAD GT-3071 spec turbo kit with free-flow exhaust elbow
Coil on plug
Vipec ECU
MAD loom
MAD cams
MAD mapped

Gearbox is Fix-It (ex YUM box), built by Bara Mortorsport. 60nM centre VC
Bara built Quaife ATB front & rear diffs, final drive is 3.9:1
ZOO Beam.
Compbrake TCA's
AP 330 / 4 pots front, Compbrake 300mm rear/standard callipers.
Toyo T1R tyres (extra load)

 

Nice work mark

 

Superb result

Glad I've gone for this turbo

 

The one difference between this turbo and yours that will effect top end power potentially is due to the headwork this one was tried WITHOUT the antisurge porting, where as yours has been ordered with it, and in theory the surge porting loses you a bit of top end (but is required on a more standard head to allow a decent amount of midrange boost)

 

Chip,

No one seems to know what my head has had done
We think it is the following:
The ports just smoothed, and the throats opened a small amount

So Mark said go for the ported shroud

We do know it wasn't really much that has been done when you consider what you can do

How much would it lose you top end do you think?

 

Very good power !

Using this turbo ?

http://www.turbobygarrett.com/turbob...30/GT3071R.htm

 

Good result

 

wow!

 

Awesome turbos!

 

Yes mate, a version of that.

 

I havent seen them tried back to back so cant give you an accurate figure mate.
If you want a guess maybe 10bhp or so less for the ported one on the same engine, but that really is only a guess from seeing other ported versus non ported not that specific one.

There are 3 differences between this and Rich's which add up to 40 odd bhp difference:
Headwork
Non ported shroud
Better intercooler

I suspect the surgeporting is the smaller of the effects if anything.

 

Here is the 2.7 bar run in black:



(the red one on that graph is the "before" figures with the 3076 and NMS cams and old intercooler etc)

 

That second graph really does show the difference, and quite bad really, moving from a 3076, down to a 3071 and that happening! Just goes to show, once you get it all right...

I have a hart inlet and will be getting the Spec-R cooler Chip, so maybe I'll sit halfway, who knows?

 

Great power that, hopefully I will be taken around the block myself

 

I guess with a .82 housing it's on an external wastegate?

Wish I had some money for a spec like this.

 

I'm almost certain it is interally gated Stu

 

Yes it just goes to show that even with a bigger turbo if the spec isnt right then you're pissing in the wind.

Seems perfectly reasonable to me that you would do so if you are getting the cams too?

 

you can get internal and external housings at .82

I assume doug is still on external as he didnt mention a change to internal.

 

Totally agree, shame to see that from Karl really

Yes got the same inlet cam as Rich, std exhaust cam

D'oh of course Doug would have already been external wastegate on the 3076

 

Looks like there were improvements to be made with the 3076 setup if it 'only' made 480odd.
The way it comes on power now looks pretty brutal. Is such a steep climb such a good thing?

 

As i mentioned it was a bit of an evolved spec, so Im not sure how much say Karl really had in its totality, for example I dont know if it was Doug that choose the .63 housing on the 3076 to cut down lag or Karl, and the .63 is proven to be a bad combination on the GT30s IME, so if that was a decision Doug made and Karl had to map around it for example then it wouldnt really be fair to say the results reflected on Karl etc

So I am sure that this didnt represent Karl at the top of his game.
Anyway, I really dont want an NMS vs MSD thread as personally Ive got a lot of respect for both of them anyway.



Doug's on marks latest cams, which is for both of them, so you arent quite on the same as him I believe.

Its possible to run a 3076 on internal gate as well, although not common.

 

Looks nice Can we see boost instead of torque (for before and after)?

 

Agreed, I did say to Doug that as he already has a similar sort of spec other escort cosworth (T38) that rather than go 3071 I thought he should go for a bigger housing on the 3076 with marks cams and the vipec etc and shoot for 600bhp and no more lag than he had before, but he was more interested in less lag than more power, so went this route instead.


Escorts do tend to really cope well with a massive surge in midrange, especially as doug tends to quite like to put his footdown on the open road a fair bit, its the massive midrange acceleration that he really likes.

For a rwd trackday car I would agree that this is far too brutal, but for 3rd gear in a straight line in a 4wd escort its awesome for putting a big grin on your face I should think, especially on the short gearing (I'll let you know when ive driven it, lol)

 

It was 2.4 bar before, and 2.7 bar after, but I dont have that on a graph.

Mark can no doubt get the rolling road to come up with it though.


The old turbo was holding on to boost better at the top end too IIRC, this one tails off down to 1.9 bar at the top from what Doug was saying.

 

Well played Mark, your getting the hang of this lark.

 

Be good if we could see that, I recently dyno'd Jason Franco's Escort (GT3076 .63) and it comes on power within 75 rpm of that graph with a lot less boost. Don't take any of that the wrong way I'm not knocking it at all, its nice to compare

The tags have started!!

 

Can you post the graph up then Martin, it would be interesting to compare.

 

My request first

 

Thought you were genuinely interested rather than playing stupid games TBH.

I dont have the graph that you are asking for so cant post it yet where as obviously as its your rollers you can get the franco one very easily, but feel free to be a knob if you want to about it

 

Very impressive, well done everyone!

 

Just to give a definitive answer on this, Ive just spoke to him and Doug is on an INTERNAL wastegate now, he swapped over to that as well when he did the conversion.

So you were right with your first guess James!

 

Makes a change

Thinking about it, Mark does like the very expensive external wastegate manifolds!
Don't get me wrong, they work amazingly well, but it is a lot of money!

 

That's damn good going.

How would it compare with a T4?

 

Doug was just on a pikey external wastegate setup in the first place, it was just a Reyland modified trouser section with a standard manifold.
Im sure if he was on a twin scroll primary designs manifold or similar, it would have remained, or more likely it would have been used with a 3076, as the twinscroll helps them spool.

When I said Doug gave Mark carte blanche, it didnt extend quite that far

 

Not being a knob, just wanted to compare boost plots thats all!




Jasons boost is pretty conservative as its not on long studs and I wanted to keep it reliable.

 

Not sure with the latest trick roller bearing T4's as only really seen them used on a stroker YB which doesnt really compare, but compared to a "normal" T4, its massively more responsive, the old T4 engine was fucking horrible really!

 

Nicely done !

Surprised to see Dave Pritchards name as engine builder but I certainly would recomend him !

 

Ii quite like my t4 engine lol.

Was just interested how it would compare though, obviously the 3071 with come in earlier, but does it hold out as long as the t4 can?