Boost levels?

[Diver944]

ORIGINAL: Frenchy

........ how do i get the beasty to hold onto boost longer []

Jim, if you want to start holding higher boost up to the red line then I'm afraid it's time to change the turbocharger as we have found over the years and many Dyno Days that it is this holding you back. Proper dual port wastegates and electronic boost controllers can improves matters but not at higher RPM. About the best one that we saw on a standard K26/8 turbocharger was David Benjamins car with a Tial wastegate and Greddy EBC:

http://www.cannell.co.uk/images/Dyno_Graphs/F835VJT_BAR.jpg

As you can see it managed to hold 1.2bar for around 2000rpm before dipping to a respectable 1 bar by the redline

 

[Guest]

Mine is totally standard ....... ! Tut Tut now Gentlemen.....[][]

You are all making me green with envy....! Some nice setups there....![]

 

[edh]

Frenchy - The boost will drop sharply with a boost enhancer because you're dropping down to the wastegate pressure once the valve is open - mine holds at 11 psi. There aren't many occasions on the road when you're still at WOT over 5k, so you still get the benefit of the higher boost in most situations.
I was running 1.2 bar with the standard injectors without a problem, on AMD chips with a LBE. It might be a bit more of an issue with a DPW and 1 bar @ 6k rpm!

FWIW, John @ Vitesse won't support his MAF with standard injectors as he believes them to be too borderline.

David Benjamin's car had a huge amount of torque didn't it? 370 'ish (Is that becasue it's a red car? []) It was running a Tial DPW, so was also able to hold boost for longer.

 

[944 man]

Whats the flow rate of the standard injectors (in CCs)?

 

[appletonn]

I thought the standard Bosch ones were 370cc/min or 35lb/hr.

 

[edh]

that's right Nick

 

[Sly]

2,5L + 75lbs injectors + modified WG with stronger spring + modified snorkel + 3b fuel régulator + forge dump valve + big valves intake and exhaust + full LR 3" exhaust + LR75#8 T350 + VR MAF + VR piggy back + accuboost + bosch WR5DC sparkplug.

Stock intercooler, stock airbox, stock intake line after turbo

Il run 19-20 psi boost with some knock between 3500 and 4500 and after 5500rpm.

On 5th gear :
- 9psi at 3000 rpm
- 15psi at 3200 rpm
- 18psi at 3300 rpm
- 20psi at 3500 rpm
- 19,5psi at 4000 rpm
- 19,5psi at 5000 rpm
- 19,3psi at 6000 rpm
- 18psi at 6500 rpm

[]

 

[u63af]

I have a 1990 Promax chips, dial dpw, 3 bar fpr, greddy profec. I am only running 16 psi as I was advised my injectors will be almost maxxed out at the redline if I run any higher boost. One thing that I thought was strange with some of these kits is that they keep the spark plugs standard. I have changed my plugs to a grade colder to hopefully reduce the risk of pre-det in the engine. Once I get 55lb injectors then I will run higher boost as running lean should not be an issue.

Agree with the other guys with red cars in the fact that red cars are the fastest.

 

[Fat Albert]

My one (with Boost enhancer) runs up to 2.0 bar on the boost gauge in the dash...

 

[u63af]

I would advise not tuning your car using the standard boost gauge supplied with the car. They are innaccurate. You will probably be running around 1 bar of boost if it is going to 2 bar on the factory gauge. The factory gauge measures pressure at atmospheric pressure. Our atmosphere is 1 bar so in effect 2 bar on your gauge is 1 barof turbo pressure. Best to tune using an aftermarket boost gauge.

 

[Sly]

The most important problem is he don't know the exact pressure. It can be 1b or 1,5b...

ORIGINAL: u63af

I would advise not tuning your car using the standard boost gauge supplied with the car. They are innaccurate. You will probably be running around 1 bar of boost if it is going to 2 bar on the factory gauge. The factory gauge measures pressure at atmospheric pressure. Our atmosphere is 1 bar so in effect 2 bar on your gauge is 1 barof turbo pressure. Best to tune using an aftermarket boost gauge.

 

[zcacogp]

ORIGINAL: appletonn

(Hi Oli! )

Hi Nick! []

I'm running between 14.5 and 14.7 PSI in my S2. At all revs; it is held from idle all the way through to the redline.

Any more than that is more than a capable driver needs!


Oli.

 

[appletonn]

ORIGINAL: zcacogp

ORIGINAL: appletonn

(Hi Oli! )

Hi Nick! []

I'm running between 14.5 and 14.7 PSI in my S2. At all revs; it is held from idle all the way through to the redline.

Any more than that is more than a capable driver needs!


Oli.

 

[edh]

Mine is set to 18psi max dropping to 11psi at redline (measured on separate VDO guage)

LBE, 26/8, Vitesse MAF, 72lb injectors, 3 bar FPR, LR stage 1 intercooler, std wastegate

last RR test in 07, hitting 1 bar@ 3800 in 3rd gear (with a boost leak)

on the road today - 1 bar @
2900 - 5th gear
3200 - 4th gear
3500 - 3rd gear

I have an MBC & waiting to get a DPW fitted at some point - there's always something else to do first...I've just changed to non-stealth MAF & I think it's boosting earlier.

The benefits of these setups with the standard turbo aren't so much peak power, more in great big wodges of midrange torque

Is it time for another "rollers of truth"? (but only after I get my DPW fitted - and after Peter's supercharger is plumbed in )

 

[ukporker]

ORIGINAL: Diver944

ORIGINAL: Frenchy

........ how do i get the beasty to hold onto boost longer []

Jim, if you want to start holding higher boost up to the red line then I'm afraid it's time to change the turbocharger as we have found over the years and many Dyno Days that it is this holding you back. Proper dual port wastegates and electronic boost controllers can improves matters but not at higher RPM. About the best one that we saw on a standard K26/8 turbocharger was David Benjamins car with a Tial wastegate and Greddy EBC:

http://www.cannell.co.uk/images/Dyno_Graphs/F835VJT_BAR.jpg

As you can see it managed to hold 1.2bar for around 2000rpm before dipping to a respectable 1 bar by the redline

I own this car now - all this torque is great on dry roads but in the wet it can be "alarming".
I turned the boost down to the low setting (11 PSI), on the EBC, during the winter as I often ended up spinning the wheels, in third, on wet roads. [8D]

I havent modified the car anymore - what David did is plenty for me.

 

[Flick]

ORIGINAL: Fat Albert

My one (with Boost enhancer) runs up to 2.0 bar on the boost gauge in the dash...

So does mine, by 3k on a K26/8(?) and a 993TT d/v. I can't remember what it does over 5k as my eyes were elsewhere.

Albert, you know that's only 1.0bar boost?

Regarding EBC's, I used a Blitz SBC spec S on my MR2 and it was totaly reliable, most owners who had tried a few prefered it to either the GReddy Profec B (but that can be used with the EManage which is very handy) & the Apexi stuff, the latter coming in for consistant criticism for being fragile & unreliable but anything was better than a MBC. May be some use to you guys?

 

[944 man]

ORIGINAL: appletonn

I thought the standard Bosch ones were 370cc/min or 35lb/hr.

Brilliant, thank you. I dont mean to worry anyone but 370cc injectors are only good for just under 300bhp! Anyone running them in an application equalling or exceeding that needs a KnockLink or a wideband lambda which they keep one eye on all the time, think:

[]

Simon

 

[944 man]

ORIGINAL: Flick

ORIGINAL: Fat Albert
My one (with Boost enhancer) runs up to 2.0 bar on the boost gauge in the dash...

Albert, you know that's only 1.0bar boost?

The reason being that one bar = one atmosphere; so two bar is equal to one atmosphere of increased manifold pressure, over and above the constant atmospheric pressure.

 

[pauly]

ORIGINAL: 944 man

ORIGINAL: appletonn

I thought the standard Bosch ones were 370cc/min or 35lb/hr.

Brilliant, thank you.  I dont mean to worry anyone but 370cc injectors are only good for just under 300bhp!  Anyone running them in an application equalling or exceeding that needs a KnockLink or a wideband lambda which they keep one eye on all the time, think:

[]

Simon

Is this on the standard fuel pressure or regardless ?.

 

[944 man]

Its a rule-of-thumb, so it doesnt allow for an increased pressure, which'll increase the flow. You really only want to run your injectors at about 80%, of course.