Technical Question??

[tegunulgener 84]

Hi everyone,

 

I've recently bought S5-210 with charge cooler. I was wondering, do I need an oil cooler? I am not doing track days. Just for street use. 

 

Also another question;

 

I've seen Deatschwerks injectors. I can see that injectors are for port but not direct. What are the benefits if I purchase those injectors? I guess D4S using direct injectors on some point.

[Pitman 188]

I am sure our Sprintex fan club will be along shortly to answer your questions.

 

For street use only, I would not think that an oil cooler would be that necessary.  Best thing to do is monitor your oil temp via Torq, and see what readings you are getting.  I have an oil temp / pressure gauge on my car (and an oil cooler), and my oil temp on the road rarely gets higher than the opening temp of the oil thermostat. 

 

As far as the DW injectors are concerned, I don't believe that the standard injector duty cycles should be stretched with a street map on the SC.  Who is going to do the mapping for you?  Best to ask them.

The D4S uses both port and direct injectors, the trick to really good mapping is to get the balance right between the two.  As far as I know, no one has yet released an after market direct injector for our cars, never mind a higher flow one.

[rob275 1817]

 

Hi everyone,

 

I've recently bought S5-210 with charge cooler. I was wondering, do I need an oil cooler? I am not doing track days. Just for street use. 

 

Also another question;

 

I've seen Deatschwerks injectors. I can see that injectors are for port but not direct. What are the benefits if I purchase those injectors? I guess D4S using direct injectors on some point.

 

 

For street, you will not need an oil cooler the injectors will also give you no benefit

[tegunulgener 84]

That's what I thought but wanted to ask just in case. Thank you guys...

[GT Nige 18]

Just to clarify something on Pitman's excellent post, updated Port injectors are available in the aftermarket but not the Direct Injectors...

[Pitman 188]

Thanks, Nige - I have corrected my typo 

[tegunulgener 84]

thank you guys... once more.

 

I have to correct myself as I meant D4S is using both port and direct injection. So, why are they selling only port injectors? My logic says that if the system requires 2 different injectors then they should sell both type not only port injectors, shouldn't they? I know also with tuning it is adjustable but port injector usage causes carbon build-ups around valves. 

[Kodename47 446]

port injector usage causes carbon build-ups around valves.

No DI does. The 2 systems are separate, I doubt that any compatible DI injectors are about and if they are they will be more expensive that the port ones and more difficult to swap. If you can get port injectors that satisfy the fuel requirements then why bother with the DI? The DI already is capable of providing more fuel than the port system but is more limited due to the fact it's single mode injection.

[tegunulgener 84]

hmm... thank you for the correction. 

 

"If you can get port injectors that satisfy the fuel requirements then why bother with the DI?" according to d4s system, on high revs only DI is active (of course it is tweak-able)

[Kodename47 446]

"If you can get port injectors that satisfy the fuel requirements then why bother with the DI?" according to d4s system, on high revs only DI is active (of course it is tweak-able)

Stock both are active at high RPM, 20% PI and 80% DI. It's DI only through most of the range during WOT. However its a full 3D table so varies with load and revs.

[tegunulgener 84]

so injector upgrade is based on 20% part of the capacity... and the tweak with the ecu. it must be a very complicated and/or sensitive tuning. it might end up with disaster i guess. of course depends on who is tuning but in this case it is really not worth to spend around £300 for the injectors (plus around £80 for the fuel pump) unless the car is going to be setup for drag races or show etc.

 

sounds like unnecessary to me for street use but maybe on next stage?

[Kodename47 446]

You upgrade the fuel setup when the standard setup cannot cope and is nearing full duty cycle. However on petrol you'd have to be pushing over 300bhp to do that.

Its not 20% capacity, its just that the PI delivers 20% of the fuel injected at that point on the stock map. To put into perspective, the DI can cope with injection time of 6-7ms, PI up to ~15ms. On stock configuration the car is little more than 3ms on either. As the DI system is much higher in pressure it delivers more fuel for the same injector pulse width.

[tegunulgener 84]

@knightyrider;

 

i am confused. really. let me write what i've understood from you.

 

on stock (hi rev)

20% PI and 80% DI

 

what they sell is PI injectors so,

whatever I am going to spend is just to upgrade that 20% part of the injectors however after upgrade it can be re-adjusted. this is what i meant. 

 

please correct me if i misunderstood.

 

ps: yes i am planning over 300 for future. like stage 2 with internal engine upgrades etc... maybe even biger ports, different cam, much higher revs, bigger s/c etc... of course this is just a plan yet.

[Kodename47 446]

Don't think about % think of it as fuel volume.

A lot of that list will be interesting, cams and higher revs will equals a big budget to do properly. I doubt it would be worth the risk of a higher limit on a bigger charger.

[tegunulgener 84]

sorry,

 

what do you mean by "big budget"? and what do you mean by "risk of a higher limit on a bigger charger"?

[Kodename47 446]

Going higher revs will be more than changing the limiter, improving the oil system to maintain pressure and internals would need to be spec'd to suit. You'd have to build from the ground up with all those goals in mind and that's not cheap, quick or easy. I just think if you're running big boost you could get high enough figures without the extra headache of trying to run higher RPM.

If big HP is your goal, it might be worth switching to turbo in the future. Although the 335 on a moderate pulley would be pretty good, along side any of the larger centrifugal offerings.

[tegunulgener 84]

Thank you knightyrider