Fitted a Dual port Wastegate

[Gordon Attar]

Sorry not been very active lately

Purchased a spare Lindsay system for £350, with a manual boost adjuster and boost gauge. After some initial disappointment on lack of difference when the std is now a minimum of one bar and I was expecting a bit more response under 3k.

But the system seems to have now freed itself up and I'm getting and extra surge around 3500 rpm and boost guage briefly goes up to 1.4.

Just checking if this is normal and can anything be done to get a little more response lowe down the rev range? and what level of boost can you tweek it to for the occasional mad fling, seems to have 3 full turns on the dial?

 

[Diver944]

You can turn it up to whatever your turbocharger will produce, BUT you need to make sure your fuelling will match the level of boost or you will run dangerously lean and eventually destroy a piston or two [] Do you have any aftermarket chips and what level of boost are they designed for? Most are written for a maximum of 1.2bar if you also uprate your fuel pressure regulator to a 3 bar model (standard is 2.5 bar)

3500rpm is about spot on for a K26/8 turbocharger with a DPW, you can reduce it a bit more by spending a lot more money on a MAF system, larger exhaust, larger intercooler pipes. Make sure you have no boost leaks first and that your dump valve is airtight, the standard one wears out and leaks

 

[DavidL]

I feel a visit coming on, but I'll wait for my new toy to arrive and drive that for a bit so I get a decent comparison!
Presumably you have replaced the chips too?

 

[sawood12]

When I fitted my DPW I turned the MBC right down to minimum and slowly cranked it up to the same as stock boost i.e. 0.7bar as I was on stock chips. As soon as I changed the chips to 1 bar boost chips I cranked the boost upto 1 bar. I have never experienced boost spikes and I get very consistent levels of boost in all gears, all ambient temps and under all conditions. I've found the MBC to be a very very reliable and effective boost controller. I can't think why you would be getting boost spikes assuming you've installed everything correctly. You have bypassed your cycling valve havn't you, and blocked up the cyling valve input from the intake boot??

 

[appletonn]

ORIGINAL: sawood12

When I fitted my DPW I turned the MBC right down to minimum and slowly cranked it up to the same as stock boost i.e. 0.7bar as I was on stock chips. As soon as I changed the chips to 1 bar boost chips I cranked the boost upto 1 bar. I have never experienced boost spikes and I get very consistent levels of boost in all gears, all ambient temps and under all conditions. I've found the MBC to be a very very reliable and effective boost controller. I can't think why you would be getting boost spikes assuming you've installed everything correctly. You have bypassed your cycling valve havn't you, and blocked up the cyling valve input from the intake boot??

I also have LR MBC and dpw and, like Scott, have never seen any boost spikes.

Recently fitted a stand alone vdo boost gauge (in psi) and relocated my MBC to the centre console. Have set it to 1.1 bar (16 psi) for now and the MBC seems to be doing a very good job of controlling the progression of the boost.

 

[nags]

Just for clarity, is 0.7bar the standard setting for both the 220 and 250hp models? if not, what is the factory boost for the 250hp engines?
Anyone got a view to what a somewhat 'safe' (upper) boost limit is?

 

[appletonn]

I thought it was .75bar for the 220hp cars and .85bar for the 250 ones, but could be wrong...[8|][]

 

[nags]

That's why I ask, I'd heard 0.85 (for 250's) as well.

 

[appletonn]

In terms of a 'safe' upper limit, it very much depends on what the chipset you are running is mapped for. Mine is a Lindsay Racing set that sets the fuelling etc to cope with up to 1.2bar. You can increase the boost sky high, but if the engine runs too lean at those boost levels, then you will melt something[8|].

 

[nags]

Well, it's being dyno tuned/mapped at the moment (with a new DPW) at standard 0.85bar boost. But looking ahead, I wonder what I might push through it. It feels like 1bar would be the logical next step..

 

[appletonn]

I asked Dave Lindsay (of Lindsay Racing, strangely enough[]) what boost level I should set as my limit with the LR chipset I've got and his reply was that 16-17psi should be the limit, as in his experience there was no real gain in hp above those levels with the standard K26/8 turbo, as it cannot physically flow any more air. Not to mention, putting your HG under more stress...[8|]

 

[sawood12]

At 1 bar you will need a 3 bar fuel pressure regulator and you shouldn't go much above 1 bar boost on stock injectors. At 1 bar with a 3 bar FPR your stock injectors will pretty much be maxed out.

 

[Gordon Attar]

Guys
Sorry started this thread then disappeared. Last week I drove it for a good 500 miles and everything seems to have settled down, strange how everything on this car needs to be 'run in'! In answer to your responses, for which I thank you.

- The dump valve was replaced when the DPW was fitted.
- The spike has gone
- I'm on the std fuel system and chip!
- Car is set on the minimum 1 bar
- and I have a boost gauge

now that its 'run in' a bit basically from 3500rpm to 5000 rpm its runs up to 13/14psi and then goes back down to 10psi so basically she's flying.
Regards
Gordon

PS I may be able to get a chip and the fuel pressure regulator from my friendly specialist

 

[sawood12]

I would recommend a chip. I did have an issue on cold days where the overboost protection kicked in. It happened a couple of times. This is because the stock chips assume a certain rate of boost build-up and with a DPW the boost builds so much more quickly it can trick the DME into thinking you are going to overboost and cuts back the ignition. It's not a pleasant experience. I'd definately go for aftermarket chips with a 3 bar FPR if you are going to increase boost any more (it would be a shame not to!!).

 

[nags]

I'd been experiencing some intermittent boosting problems, where it wasn't making full (or sometimes any) boost pressure which I mentioned in another thread. After some digging, the wastegate was given the blame and a new DPW was ordered. I've now received my car back and had a drive of it over the weekend.
Ultimately, I had the following work done;
DPW
Boost controller
Chips (and tuning)
New AFM and lambda sensors were also fitted as the originals had been spitting out dodgy readings during the tuning process.

Power is up to 307hp at 13psi having been wound back from 335 for reasons of mechanical longevity. In terms of 'seat of the pants' feel, the power is definitely there - I notice it most at the top of the rev range, where the boost used to taper off, but now holds true and also on the motorway where pull through 4th gear has been given a new lease on life. I would say that the biggest improvement is with the delivery of boost (earlier, faster and longer).

So, that solved the intermittant boost problem then!

I am happy to recommend the workshop in a PM (assuming I can't name them here?).

 

[pauljmcnulty]

I am happy to recommend the workshop in a PM (assuming I can't name them here?).

I don't see that as a problem? I don't like "naming and shaming" as there's always someone who abuses it, and specialists can't come on and start promoting their business unless the question has been asked directly (like with the non-pop-up light thingies or the clear lenses threads recently).

If you're happy with a company and their services might benefit others name away! []

 

[Diver944]

Yes, independant praise is aways welcomed when we've had a good experience. After all, how else are we all going to know who's any good [&:]

 

[rcsalmons]

ORIGINAL: sawood12

I would recommend a chip. I did have an issue on cold days where the overboost protection kicked in. It happened a couple of times. This is because the stock chips assume a certain rate of boost build-up and with a DPW the boost builds so much more quickly it can trick the DME into thinking you are going to overboost and cuts back the ignition. It's not a pleasant experience. I'd definately go for aftermarket chips with a 3 bar FPR if you are going to increase boost any more (it would be a shame not to!!).

Thought the overboost protection was bypassed when fitting a DPW, what set up do you have?

Rich