Building a 400bhp+ 2.5 ltr 944 Turbo

PSH · Jun 21, 2020

Nothing wrong with those prices...

When my son first got his new machine he charged £35 for a few months but you aren't going to make any money like that. Most places near him charge £60-£70, hence why his is £55. He knows his market, since it costs me nothing it makes no difference.

Waylander · Jun 22, 2020

Did I say he was charging too much, nope £55 for personal service is good value, it was just a statement that I got mine done on a Groupon deal

PSH · Jun 22, 2020

Waylander said:
Did I say he was charging too much, nope £55 for personal service is good value, it was just a statement that I got mine done on a Groupon deal

Hmm.. sorry Martyn I clearly didn't write that very well, I was referring to the prices you and Paul got, hence why I said 'prices' When my son was doing his at £35 it was as a 'lost leader' to drum in business for his new machines but you can't sustain business at those prices. When he got his new machines for his new premises he bought both types, so R134a and whatever the new gas is, forgot that code? I recall it's a longer number and going from the prices advertised around here a lot more expensive, at least double although I have no idea what my son charges. IIRC, when I got my MOT done a couple of weeks ago they were charging £65 and were charging a car at the time so can't be too expensive, they are less than 2 miles away from my son.

Cheers

Pete

blade7 · Jun 22, 2020

Groupon are taking their cut, so ATS are probably getting £30-35? Having said that they do hundreds of recharges around the country, so it's a probably a way to get you in, and maybe sell some brakes, tyres or exhausts.

TTM · Jun 24, 2020

The "Super" series turbos from Lindsey Racing are named after the peak flow capacity of the compressors used.

They are off-the-shelf Garrett T series turbo mated with a KKK-style turbine housing made to match the 951 cross-over pipe and exhaust set up. For instance a "Super 61" uses a compressor which can flow a peak of 61 lbs/min.

A Super 61 may actually be a T04B 60-1 (sixty-one, sixty one...?)

Someone said once that 10 lbs/min of compressor flow roughly equaled to 100 engine hp, but this rule of thumb probably assumes a volumetric efficiency of 100%, whilst a 944 8V head, even maxed out by the very best CNC port work imaginable, probably won't get anywhere near 80%. This is where we sometimes hear folks claim that something like a LR Super 65 turbo will make 650 hp on a 944 turbo... no chance, at least not with an 8V head running real life levels of boost and a streetable camshaft.

PSH · Jun 24, 2020

Good teply Thom...I never said the 61 would give 600+ on a 944, just that it's capable of that if the rest of the components allow.. The 61 is actually a little big for a 2.5 but with a high duty cycle can be very responsive...bigger turbo's are pointless on a 8v 2.5 IMHO

blade7 · Jun 24, 2020

Just about everyone on the Yankee forums said a LR 61-10 was too big for a 8v 2.5. Including some that may have known what they were talking about [

].

PSH · Jun 24, 2020

There are also those who say that with a 61 on a 2.5 getting over the 400bhp mark at the wheels isn't a problem, some achieve much more...clearly, I do know what I'm talking about.

blade7 · Jun 24, 2020

TTM · Jun 25, 2020

Pete, my message was not supposed to be a go at anyone. I know it is possible to make 400hp on a 2.5 8V engine but that would not be with all the standard hardware between the compressor outlet and the combustion chambers.

Dan944t · Jun 25, 2020

i have a question if i may? ....my next power mod is going to be my custom made 3” exhuast all the way through other than the down pipe, which i understand is best left the size it is? ...... But my main next thing which i overlooked and rebuilt mine is a bigger turbo to mary all my current mods together.,,,,

Now my question is,...what would be my ideal turbo preferably available in this country. ill be aiming for the 350-450 mark with quickest spool up as possible.

i will be installing it so doesn’t have to be bolt on i can make/weld things up to fit

Daniel

PSH · Jun 25, 2020

TTM said:
Pete, my message was not supposed to be a go at anyone. I know it is possible to make 400hp on a 2.5 8V engine but that would not be with all the standard hardware between the compressor outlet and the combustion chambers.

No prob sir, I certainly never took it as such...

PSH · Jun 25, 2020

Hi Dan

Not sure where the bigger downpipe comment comes from, you do need the 3" for the power you wish for. Yes 3" for the entire exhaust system, you can get bigger but it adds little to nothing, some say it happers power above 3", who knows.

Not sure about turbo's made here, talk to turbo technics or universal turbos to see if they have anything to offer, they should both be familiar with the 951 mount. Turbo's have moved on a long way since I bought my 61, with more modern bearings/design they will spool quicker but for the power you want you will be looking at a similiar sized turbo. The bearings in my own have been improved twice for each time it was rebuilt, new impellor last time too.

Spool time isn't just about the turbo, duty cycle, wastegate spring among other factors also have a bearing on this.

I have read good things about the 'Vodoo' turbo, if I was in the market today I'd certainly have it high on the list. IIRC the vendor (sorry forget his name) has recently put feelers out on FB to make a new batch of these turbos.

Check out the various 944 turbo pages on FB for details.

Pete

Dan944t · Jun 25, 2020

hi Pete, the manifold down pipe i mean not the turbo one?

what manigold size have you got Pete? are you running a custom manifold down pipe or standard? i know the rest of your system is larger.

think it was wayne scofield that told me the standard size down pipe is the best , the rest of the system 3” . all to do with the back pulses, where he said bigger is not always better but most people don’t understand he said. and i agree as it’s all science.

i did speak to turbo techniques last year about a hybrid ceramic ball bearing turbo but forgot the specs now. it was pretty expensive pete, if i’m not mistaken i wouldnt have much change from £3000 by what i remember

i’m in the process of building my home head preasure tester for crack detection so once i get things sorted the next thing will be the exhuast and turbo build so i can build the down pipe into the new turbo exit flange.

tes i understand the spool is made up from the duty cycle and wastegate spring although i don’t know anything about setung the duty cycle up or ins and outs exactly how it works, i’ll be modelling it on yours i think.

i have the Tial 38mm dual port wastegate which john micheal told me was well capable of this sort of power with quick spoil. just need the exhuast and turbo next and then i can enjoy my engine mods and hard work more till i’m ready to increase boost past 19-20 then i’ll have to get the maff and duty cycle and stand alone......Might Have To Sell One Of The Kids

PSH · Jun 25, 2020

Hi dan

I am still using the standard manifold, I had planned to upgrade this for the SFR pipe but decided it wasn't needed for the power planned. Back pulses will still be there... Porsche designed the system so that the turbo outlet is smaller than the downpipe anyway, it still is with a 3" and then flows freely having just the one step from turbo to downpipe. If adding a 3" system and leaving the downpipe standard you now have two steps, turbo to downpipe and downpipe to exhaust pipe. This for me is not beneficial to good flow, perhaps better off just keeping the standard exhaust, I say perhaps, not being a velocity/flow /volume expert, although I do have friends who could tell me exactly the characteristics of a given setup.

Turbo's in any form are not cheap and of course, with more modern turbo's things get more expensive. Here's a link to the guy on FB for his voodoo turbo, he's well respected in 951 circles. [link=https://www.facebook.com/photo.php?fbid=10222036504236791&set=pcb.3357513437605569&type=3&theater&ifg=1]https://www.facebook.com/photo.php?fbid=10222036504236791&set=pcb.3357513437605569&type=3&theater&ifg=1[/link]

A good performing engine needs a lot of things to add up, you need to match the CFM as best as possible and the turbo to be above that figure. So headwork, intercooler, pipework, inlet etc etc, there will always be one part that restricts but despite what you may read, the 951, in general, isn't bad. Duty cycle is controlled by an electronic solenoid which holds the boost. So 0% duty cycle means no solenoid operation and relies purely on the wastegate spring, you can fit a stronger spring (I have a 4.5mm spacer which I machined to increase spring pressure in my wastegate and used a new spring and diaphragm) but this doesn't give you everything that you need and too strong a spring is bad. The solenoid which you control from your EBC will hold the boost at the level you set, however, if you set the duty cycle too high you will get boost spikes. The higher the duty cycle the better the response from the turbo (you still need a good spring), I can't recall the average duty cycle setting as recommended for boost setup by my Apexi, maybe 35%. From that point, you then drive and test how the turbo responds if it's taking too long to spool for your liking then try increasing the duty cycle. I used to have mine at 85%, I reduced it a little to 80% when the larger injectors were fitted and ignition was recently changed. I have noticed a slight drop in response but nothing much, I will probably increase it again soon when happy all has settled in, BTW my son has his cossie duty cycle with his massive turbo set at 100%, but then he's mad. even with that duty cycle his turbo still takes time to spool up, as I tease him on when I hear him trying to get on boost while coming down my close, you know how short that is...

As a safety, I have a stepper boost gauge that gives me an audible warning at a set boost level, this is to warn me when the boost goes above what the EBC has been set too, which it will as a matter of course with a high duty cycle set. I then know to back off a little to reduce the spike. having the Vitesse MAF+ I have the added security of setting a boost level for the ECU too so any spike above 1.5BAR is very short-lived, the engine as built will cope with higher levels than that anyway.

I'm not very familiar with Tial but do recall reading that you want the larger size for big power, I don't think that the 38 will achieve the power you want? I stand to be corrected if I have this wrong.

Pete

Dan944t · Jun 25, 2020

hi pete, i did ask john about the sizes as i wanted the one in the 40 range and he said no it’s too large and to go to this size

what DPW are you running Pete and what size?

yes i am going to change the single down pipe from the turbo outlet down to the new exhuast system to 3” as i know the inside is around 2.5 or so if im not mistaken? so mine will all be 3”” all the way through. i was referring to the main manifold down pipes (leaving them standard size which wayne told me to as any bigger will be detrimental to the flow and build up and reverse pulses ect so i just agreed. we both agreed that if money or time was no object i would make a less restrictive manifold down pipe , but really doesn’t seem that worth it with a turbo system , so i’m keeping it standard for now.

i pretty much have everything in place including larger injectors for big power it’s mostly the turbo and exhuast , and electrical items stopping me making big power. so the way i’m looking at it in the very near future my goal will be turbo , and exhuast system once i have sussed out my head problem.

i have a one off custom port job dobe by me on my head which i know will come into its own with a larger turbo and a full 3” system so i have my own one off idea for that to flow larger numbers than can be bought

all beit i made my own flow bench but i still got them equal and flowing more than standard

so it’s my own little experiment that will make mine a unique set up, as no one had the same head porting as mine. im no expert and it could go tits up but with another trip to wayne i’m once im ready i’m sure he will be able to regulate things, and at the end of t he day i can always throw another head on, it’s not like i’ve not taken it off and on 20 times in the last few years

i did a bloody good job though!

it’s all fun ain’t it. the turbo is a wallet killer along with the few other electrical items i need further in future but as it stands i’m always happy just to have it to drive. one day i’ll get it back together again, once these kids let me ha ve a bit more free time

PSH · Jun 25, 2020

i am running the LR DPW which as I'm sure you know uses the stock barrel, the alloy dual billet on top is much larger but I've never measured it for comparison. IIRC the problem with the 38 wasn't so much that it couldn't develop the power but that it tended to crack under such conditions. As I say, I know little about Tial, perhaps others know more on this?

Personally I think the standard manifold is fine and being made from Inconel it's very resistant to any heat being thrown at it. I would agree with Wayne and keep the original manifold and don't wrap it.

I've always been happy with my LR head, I went a little OTT with the options list at the time, don't ask me 'what I had done' now as I forget. I do recall that one of the options they didn't do as prior to them doing my head they had a few issues with a special coating that they tried to cover the combustion chambers in, think they had reports of it chipping off and so played safe with my order.

As I said, it takes a lot of parts and development for a good reliable engine, mine was just one step at a time, well except for the last round of mods when I went mad and spent a fortune....

Dan944t · Jun 25, 2020

yes my last spend on mods was just over £6000 Pete

these are not cheap to do properly that i can vouch for ive probably spent 6 fold in mods and restoring parts than i paid for the car way back when, and 99 % if labour was free from me. i could have never got it half up to this standard of tune if i had to pay someone to do the work on the car!

blade7 · Jun 25, 2020

Dan944t said:
yes my last spend on mods was just over £6000 Pete these are not cheap to do properly that i can vouch for ive probably spent 6 fold in mods and restoring parts than i paid for the car way back when, and 99 % if labour was free from me.

And this is why ^^^I'd recommend something like a Golf R or RS3/TT-RS over a 944 turbo, for anyone looking for a 400+ bhp project today.

Dan944t · Jun 25, 2020

blade7 said:
Dan944t said:

yes my last spend on mods was just over £6000 Pete these are not cheap to do properly that i can vouch for ive probably spent 6 fold in mods and restoring parts than i paid for the car way back when, and 99 % if labour was free from me.

Click to expand...

And this is why ^^^I'd recommend something like a Golf R or RS3/TT-RS over a 944 turbo, for anyone looking for a 400+ bhp project today.

yes Blade you would be correct here,.... if someone was just looking to have a 400hp car then other options are way way way cheaper options including modern stuff, than an old girl porsche 944 turbo as it needs to be put in good shape which will cost people well over the cost in most cases depending what year they buy there 951.

In my personal situation i’ve had 944s since the age of 17 based on how much i love the shape , so i’ve been in love with them for many many years, and was never wanting the extra power until i got bit by the promax bug, and then it’s just been a buzzing experience to have that extra bit of speed to try and keep up with the everyday sports cars in my favourite car which is the 944 turbo.

ive had 600bhp m5s and a lamborgini over the years so have experienced the best pure animalistic power, but even when i sold my Lamborghini and got in my 944 turbo i didn’t really miss the Lamborghini only missed its looks. i like to be different and i like different things and for me personally i ca mr get enough of the 80s and love my porsches, si for me it’s a win win to own a 951. i have another nice convertable porsche amongst other vehicles and motorbikes but it’s my 944 turbo that i love the most and would never sell it.

if it wasn’t that i invested my money into houses and have just mooved house and 3 young kids , i’d have all my mods sorted years ago but it’s one of life’s things that other important things take priority first and the car takes a back seat.

but yes if someone only wants a 400+ sports car ,....then there are way cheaper options out there