Chris White

See more dots and lines posted above... Again - we are only looking at the compressor curves - and I still like the area under the curve for the GTX3582 compressor. I also like the area under the curve for the real world dyno results....nothing exaggerated there!

Is that opinion based on real testing or butt dyno results? I have heard that things can get exaggerated on occasion, I prefer to look at actual test data!
From our previous discussions you made the point that you liked an engine that was mostly top end performance and that was your goal. Did something change or are you just into taking contradictory positions?

I did post, several times, in that thread that is was a "Tial turbo", and yes, Blitz also posted incorrectly that it was an HTA version...but that was all cleared up. I guess I just assumed that listers would understand that I built the motor so I might just know what parts were used. I would also have to add the many listers wouldn't know what an HTA turbo was....its another modified Garret GT35 just like the Tial turbo. It uses the Garrett GT center section and adds their own compressor wheel....just like Tial did.

In reality I don't know why you find it to be a big deal - the turbos are very similar.

Chris White

You need to come up with a good way of dealing with the 70mm throttle body....or the street part of the driving will be very annoying!

V2Rocket

55mm restrictor plate in front of it

Penguinracer

Chris I'm hoping that sequential injection (Clewett cam trigger gear) & the Vi-Pec V88 which has 5D fuel mapping & can operate off MAP or a combo of MAP & TPS might smooth out the idle & low end.
I'm going with coil on plug (probably some kind of LS coils).
I've gone with Tim's Stage 2 fuel system & figured sequential might help the idle with bigger injectors & that the Tial BOV might also stabilise the idle somewhat.

blade7

Is this the engine you've been threatening to build since 2010 Pengui, You've been talking about doing one longer than me .

Thom

I am not contradicting myself anymore than you are contradicting yourself, talking about the importance of "area under the curve" in another thread then choosing an oversized turbo here.

You plotting shows (again) that the GTX3076R is the better choice than the GTX3582R. Again, plotting the rpm limit on the middle of the efficiency islands, which is where you want your peak VE (thus peak torque) is an incorrect way to proceed. If you used such a compressor as a supercharger configuration it may make sense, but this is not the case here.

As Duke suggested a few % of efficiency is peanuts compared to how much you lose in area under the curve. With your oversized GTX3582R, you are wasting the "right side" of the map you are not covering, which is where the compressor flows most.

Playing with intake and cam profile will have a lot more impact on the type of power delivery (mid range vs top end performance, etc) than trying to fight against a turbo that was not sized correctly in the first place.
A properly-sized turbo, such as the GTX3076R for a 3L engine, will shine both in mid range and top end depending on intake and cam profile. That is based on testing and clocking a running car on the road, where the load on the engine will always be more relevant than loading a car on a dyno.

Penguinracer

Blade - tell me about it! I'm embarassed with how long this has been taking!

I now have everything except for a few SFR parts which Tim is due to send in the next week or two - I received most of my order from him last week.
It's been very expensive getting everything together - Guard LSD, KEP Clutch, Spec flywheel, Elephant Racing kit, Leda coilovers, Tarrett ARBS, Raceware stud kits, pistons & rods, Drysump kit including Pace oil tank, intercooler, oil cooler, radiator,Big Brake kit, 18" hollow spoke twists & "R" compound tyres, various bearings, gaskets, switches, hoses, tranny & engine mounts, ECU & sensors, turbo, WG, BOV, braces, extinguisher mounts, intake, headers, etc.

I've had no choice but to spread the cost over time, especially as house restoration & the birth of a daughter (needing a full-time nanny) have intervened.

Also in that time the car got two new front wings - it certainly needed one as the parking brake didn't hold it & it rolled through a picket fence & into a field!

You know how expensive it is to build/modify a car in the UK - that's why so few people do it with high performance marques such as Porsche.
I'm now just waiting for the cylinder head, cam, exhaust (from the cat bypass back), fuel pump & fuel pressure gauge.

Wiring harness might be a challenge & I'm thinking about new CV joints before sending my spreadsheet to the guys I've lined up to do the work.

How's your build progressing? I opted to stay away from a 3 litre & invest in the drysump instead. The costs can quickly career out of control.
Tim

Duke

I would not do the 0.82 T3 a/r turbine housing for a 2.5l. I've tested it in the past and the lag is very obvious. So go down to a 0.63 and either do the GTX3071R or the GTX2867R. The latter would be a quicker car in autocross and have a more modern, GT3, feel to power delivery.

Voith

Yup..

Chris White: a little offtopic but what is that bart 8L turbo you have in your signature? Sounds scary

blade7

My 3.0 build stalled because I'd been haggling for months with the owner of the car that had Diver944's 3.2 engine fitted, in the end we were £1k apart and someone else bought it. So, I have the 2.7 engine, S2 crank, Carrillo rods and a big turbo, need pistons, MAF kit, exhaust, clutch, but my 2.5 with just a Lindsey L2 kit is flying so motivation to spend and pull it to bits is low at the moment. May end up sticking a MAF and the turbo on the 2.5 for this year.

Chris White

OK, so we are having a little 'fun' bench racing - but in the end I have empirical proof that the GTX3582 (tial) works quite well on a 3.0 and the 'area under the curve' is just about as good as it gets.
Past results include 350 ft lbs @ 12 psi at the rear wheels on a 8v as well as 600hp at the crank on a 3.1 16v at 15 psi. Documented real results.

I also think that the 3076 will work fine as well, I am not saying that the 35 is greatly superior to the 30, just that the 35 will preform very nicely and leave you 'headroom' to run more boost and/or higher rpm.

in the end the testing is done...it works and its works well.

Chris White

congratulations - you are the first to ask about that!!! I wondered how long it would take for somebody to notice it.

Its a Barth motorhome built in 1985, very high end at the time (nice match for the 944!). The funny thing is that the layout is very similar to a 930 - turbo charged rear engine with a trailing arm torsion bar suspension. Very uncommon for a 35' motorhome!
The body is all aluminum construction with hand riveted panels.
8 liter turbo diesel running 15psi of boost.

Its a great way to tow a track car and relax at the track between sessions. I 'camp' out at many tracks for weekend events.

Chris White

in that case it really fits in this thread - my 968 cab was last on the road in 2010....its taken me that long to get this done too!

URG8RB8

2010!, I wish it had only been that long, tore my FL car apart in 2001!

Voith

Awesome motorhome. 8.2 td @ 15psi... Sounds like tank engine. How much torque does it produce?

Any interior pics?

Btw: Since there is all this turbo talk, what do you think about 7200 K27#8 on 3.0 8v engine (stock 951 headers&crossover)? Would this make a good combination for street car with (very) few track sessions?


We could form a club. My is in parts from 07.