Stage 0 and Stage 2 ProMAX mods to 944 Turbo - long post

[TK2015]

ORIGINAL: Fen

M030 Konis will cost you more than KW if you don't have a set to rebuild. Also with a chunk more power than you have and track tyres the back of mine was fine unless it was greasy - I put that down to KW and proper alignment.

I'm lucky, mine came with the M030 option, so adjustable Koni's already fitted. ProMAX are doing exchange refurb fronts for £360 and new rears for £314, a substantial saving over the £1440 I'd have to find for KW V3.

I had the alignment done along with the 968 rear castor mounts and new ARB bushes all round.

I put the squirmy rear down to a combination of wet road and bad driving - the latter I hope to overcome!

 

[Hilux]

Level 3 kit, plus KW suspension, plus their new mother of all exhausts (imo) which Andy kindly demonstrated to me the other week - oh and better brakes, is my next plan of action if my bank balance can cope []

You should already be thinking about upgrading the brakes if they are not Mo30 as you`ve just had a large power increase.

 

[Riverside]

Glad you're enjoying the car Tom, if you're looking for a good value car control course before taking it on track try www.carlimits.com (Andy Walsh), I've done two sessions with him now & it improved my confidence massively.

Hopefully I'll get my Konis refurbed sometime soon (family permitting []). I think it's a worthwhile exercise because even if you consider changing to KW later you'll probably get the refurb cost back if you sell the Konis.

I think I'd make the gearchange the next priority though, get the basic car working right before you take it too much further imo.

 

[TK2015]

ORIGINAL: Riverside

I think I'd make the gearchange the next priority though, get the basic car working right before you take it too much further imo.

Already sorted - I had it done about a month ago - it was driving me crazy []

 

[sawood12]

I think for my next power hike i'm going for the Vitesse stage 3 kit. The chaps over in the states seem to love it, there is plenty of experience of people running it very reliably it at various boost levels on otherwise unmodified and refreshed engines, and it just does what it says on the tin. I also like the idea of being able to change to boost levels without having to remap the ECU. Also with the current $/£ exchange rate it makes the kit very good value for money. I also like the sound of Vitesse's 'Sledgehammer' cylinder head! I'm torn between my next lump of spend going on some minor cosmetic bodywork issues or just going for the performance! I've half decided to go for the full respray in a couple of years time along with new front wings and outer sills so the inner sills can be protected from inside out, so I'm leaning more towards the power in the short term!

If I had the buget i'd be knocking on Jon Mitchell's door!

RE traction - Torsen diff should sort that out. Thats job number 3 on a very long and growing list! I'm getting some bearing noise from the rear so will have to get it sorted at some stage and I can't see the stock diff staying in place.

 

[Diver944]

ORIGINAL: sawood12

I think for my next power hike i'm going for the Vitesse stage 3 kit.

The Vitesse stage III is claimed to be good for circa 340 HP at the wheels at only 17psi (on a US dyno), you crazed up power junky [] Not bad for £2000 + fitting

Might I suggest some 275 or wider rear tyres to also help with the traction [8D]

 

[Suffolk944]

You should already be thinking about upgrading the brakes if they are not Mo30 as you`ve just had a large power increase.

Yes its very much on the agenda the brakes are adequate but no more than that- I have the problem of it being an early turbo with its attendant offset issues but there a couple of options I have been discussing to get them upgraded.

 

[wizard]

Hi Tom
Nice improvement! Reminds me of the experience with mine. When I first put it on a Dyno (Jamsport) it only managed 218Bhp (and some may say that was generous). After a VERY major seeing to by Promax which included the Promax Level 2 kit, the rollers of truth at Weltmeister showed an improvement to 316Bhp with 328 ft.lb torque (which some will say is conservative). The only thing I had fitted different to you was an electronic boost controller which enables you to control the waste gate a little more.
If you haven't done already, I would recommend you fit an aftermarket boost gauge and air fuel monitor gauge too just to make sure the engine still runs healthy. Larger injectors may be a prudent choice too. My car broke in January which we think was down to a faulty injector or the fuel pump not delivering enough fuel to No4 cylinder.[][&:][][:'(][X(]

I hope to have the car back very soon (if it hasn't fallen apart already) with a resealed 98K engine and fitted with one of John Mitchells whizzy hybrid Level 3 ball bearing turbo's (built by Simon P I think), larger 55lb injectors and a motorsport fuel pump. I hoping to see improvments in spool up time and torque delivery.

 

[sawood12]

ORIGINAL: Diver944

ORIGINAL: sawood12

I think for my next power hike i'm going for the Vitesse stage 3 kit.

The Vitesse stage III is claimed to be good for circa 340 HP at the wheels at only 17psi (on a US dyno), you crazed up power junky [] Not bad for £2000 + fitting

Might I suggest some 275 or wider rear tyres to also help with the traction [8D]

Thats the kettle calling the pot black!! yes Paul, I have plans to relegate my current 17" wheels to track wheels and fit some nice 18" rims for my road wheels (can't decide between the 996 turbo wheels or the 997 carrera slim spoke ones that Rick has) anyway it all boils down to cashflow which is pacing things at the moment! Got kitchens, uPVC windows and other costly home improvements to contend with at the moment!

Wizard - i've been doing some research on fuel injector sizes and it seems to me that by running much more than 1bar on standard injectors even with a 3 bar FPR you are asking alot of the stock injectors and running them well into the 90% duty cycle area - add an EBC to the mix that holds boost longer (an MBC bleeds a bit of boost at high rpm) and this increases further the demands on the injectors and before you know it you are quickly running out of safety margin. Even though Promax have alot of experience with their level 2 kit on stock injectors I personally would like a good level of safety margin (especially when my injectors are 20yrs old) and for that reason am limiting the amount of time I hold the car on WOT and am eager to upgrade my injectors to 72lb/hr in advance of the Vitesse upgrade. I'm sure i'm being over-cautious, but when it comes to things like injectors i'd rather be. If my engine went bang now i'm sure i'd be tempted down south to Bournemouth and onwards to certain financial and marital ruin!

 

[TK2015]

Wizzard, you mention 55lb/hr injectors and Scott, you mention 72lb/hr ones. What is the rating for the standard ones and does this decline over time (i.e. do they become clogged)? Finally, how much does a set cost and are they a DIY fit job?

 

[Fen]

I think standard are 42lb. If anything that would go up over time as they wear IMO.

 

[Diver944]

The standard injectors are 34lb/hr and yes they can become clogged over time (less so if you use good quality fuel with modern detergents). They can be reconditioned and sonically cleaned back to peak performance for around £25-£30 each, but if you are thinking of further upgrades then it would be best to fit a higher flowing set like 55 or 72lb/hr which can be had for £200-£300

The standard injectors can only flow so much and as you increase boost and airflow through your engine you will need more fuel to avoid maxxing out your injectors and running lean. The Promax chips you have will already have a setting for the 55lb/hr injectors and will be as simple as physically swapping them and then adjusting the chip to suit

 

[wizard]

ORIGINAL: sawood12

Even though Promax have alot of experience with their level 2 kit on stock injectors I personally would like a good level of safety margin (especially when my injectors are 20yrs old) and for that reason am limiting the amount of time I hold the car on WOT and am eager to upgrade my injectors to 72lb/hr in advance of the Vitesse upgrade. I'm sure i'm being over-cautious, but when it comes to things like injectors i'd rather be. If my engine went bang now i'm sure i'd be tempted down south to Bournemouth and onwards to certain financial and marital ruin!

You are quite correct being cautious Scott, I regret not switching to the 55lb at the time - seems crazy now as I had 2 new injectors fitted too! []

The dyno I had done shortly after, showed my AFR being quite rich but not excessive so I made the assumption everything was fine. The only change I made after the dyno was to fit a K&N air filter which may have flowed more air for a time, but I can't imagine that would make a massive difference.

 

[Hilux]

The standard injectors can only flow so much and as you increase boost and airflow through your engine you will need more fuel to avoid maxxing out your injectors and running lean. The Promax chips you have will already have a setting for the 55lb/hr injectors and will be as simple as physically swapping them and then adjusting the chip to suit

I would imagine that you would need a high pressure/flow fuel rail and a high capacity pump?

 

[AndrewS]

Hi Paul,

The standard fuel pump and rail are fine with 55#/hr injectors. For bigger injectors (as used on L4 cars), a higher specification fuel pump is used.

A 3.0 bar fuel pressure regulator enables standard 34.5#/hr injectors to handle up to 1.2 bar boost (with suitable DME mapping) - but they are getting close to maximum injector duty cycle - hence the use of an AFR (Air Fuel Ratio) gauge is recommended. With non K26/6 and K26/8 turbochargers, it is advisable to move to 55#/hr injectors as the bigger turbochargers can hold a flat 1.2 bar+ to the redline (unlike the K26 where it tails off after 5,000 rpm).

Regards,
Andrew

 

[wibble]

Interesting read and methodical approach - like it. Also keen to get mine back to its optimum performance after the summer (what summer) is over. I need to get the brakes and suspension sorted at the first stage.

Your air-filter looks similar and wonder when mine was last changed.

 

[Hilux]

Hi Andrew

Glad to know that as you dont want marginal fuel pressures or injector diversity lost, particularly on a turbo`d engine.

I must bring the car back for a check on the suspension mods (and pay you for the oil you brought to Bedford Autodrome [][]) and see the new set up. I`m so busy I just dont seem to be able to spare the time these days.

Definitely need to chat re an upgrade as I`m going down the primarily used for track route, mind you I still have the bruises from SWMBO following my last expenditure with you guys. [&o][&o]

 

[sawood12]

Good find at work today. One of our engineers spotted me in my car and stopped me for a chat. He started asking me about the Motronic system and the questions were way above my head - turns out in a previous job he used to work on various EMS systems and specialised in the various Bosch Motronic and Motec systems. Mentioned he used to specialise fitting modern fuel injection and EMS systems to old cars, so basically starting from scratch with no, or very little, off the shelf stuff to use, all bespoke and individually tuned. I think i'll be having several in depth conversations with him going forward. Certainly sounded very knowledgable on the subject and he is one of our controls engineers so I reckon he speaks fluent binary.

Anyway it was his opinion that you don't want your injector duty cycle to be over 65% as above that the injector is basically working all the time (or saturated as he termed it). I think I need to collar him to sap his knowledge.

 

[Fen]

I thought it was 85%, but I agree it's certainly not as high as even 90%.

 

[dlknight]

ORIGINAL: Fen


I've never had F1s on my 944 (though I have had them) but my indie says they are not a good tyre for the 944/968. I'm not sure if anyone else uses them on here for a personal opinion. I don't like the tread pattern aesthetically myself.

Hi Fen,

I have F1's on the front which were put on by the previous owner, they have had some track use though and are quite feathered around the edges. Will be going for something different when they need replacing.

Dave K.