Any turbo/mappers/fueling experts around here.
Any turbo/mappers/fueling experts around here.
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Discussion

Mr Darcy

Original Poster:

1,006 posts

202 months

Friday 30th July 2010
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I recently slapped a GT2871RS turbo on my Elise 2zz-fe engine. The engine in it is a newly built low compression job (less than 150 miles on it), the turbo is only running 5psi at the moment. The map is not ideal for the car but its good enough to run it in (I think). However I have now noticed that the car stalls all the time on idle when cold and if you put your foot down (again when cold) it just stalls and dies and you get a lovely smell of petrol. Once the car is up to temp or has a bit of heat in it, it still runs a bit rich but it doesn't stall.

I don't want to cause any damage to a rather expensive engine but should I get it mapped properly, get the boost turned right up and drive with a lighter right foot or will it be ok to run as it is for a few more 100 miles?

Defcon5

6,470 posts

221 months

Friday 30th July 2010
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Running rich is better than running lean I suppose, but I would be trying to drive it as little as possible

anonymous-user

84 months

Friday 30th July 2010
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Bore wash? Get it mapped now IMO!

rigga

8,806 posts

231 months

Friday 30th July 2010
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Dave_ST220 said:
Bore wash? Get it mapped now IMO!
Id get it running properly asap may not be overfuelling enough to cause borewash but could well be diluting the oil enough to cause issues,plus should you glaze the bores of your recently fresh engine the only way to sort it would be a strip again.... for the price of a mapping session compared to the potential damage its a no brainer ..... and again wheres the fun in driving a potentially good car when its running crap .

Marf

22,907 posts

271 months

Friday 30th July 2010
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Dave_ST220 said:
Bore wash? Get it mapped now IMO!
+1

If you don't have a wideband oxygen sensor on the car then you don't want to be driving it as you have zero idea what is going on fuelling wise.

A good mapper will be able to set you up with run in map, you can then take it back to him to be properly mapped once your engine is run in.

This really is a critical time in your engines life and bore wash is something you want to avoid at all costs as the rings will be bedding in right now, throwing in loads of fuel will compromise this process.

You want a good map in there during run in so you can safely load up the engine at low revs to get the rings bedded in proeprly.

I have some experience in mapping(my last car had a programmable ECU) and to my amateur ears it sounds like the cold start fuelling correction is way out.

ps Sounds like it'll be mental when done!


Edited by Marf on Friday 30th July 12:38

Mr Darcy

Original Poster:

1,006 posts

202 months

Friday 30th July 2010
quotequote all
Will take all the advice on here and get it mapped. Don't want to rebuild it again.

anonymous-user

84 months

Friday 30th July 2010
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I suspect the lower CR will have significantly reduced low speed torque( <1000rpm) as the burn rate will be right down, also, the larger combustion area will affect the transient fuelling, with a greater volume of fuel "hung up" in the crevice volumes. It probably means the engine will require a greater idle airflow and almost certainly a more advanced ignition angle (to compensate for the slow burn) at idle, and possibly a great cold fuel multiplier. Bascially, as others have said, get it mapped ASAP before you break it...... ;-)

RobCrezz

7,892 posts

238 months

Friday 30th July 2010
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Agree with the rest. Without a wideband lambda I wouldnt risk it.

Very interested to see the results after mapping too! Great choice of turbo.

Mr Darcy

Original Poster:

1,006 posts

202 months

Friday 30th July 2010
quotequote all
Yeah I went for the disco potato as it seemed to meet my needs very well. Doesn't make the power that the engine and gearbox can handle (E154 box) but it seems very drivable. I did ponder on getting a GT3583R which could easily push the car over 500bhp but it would be very very laggy I think.

Hopefully when it does run full boost it should hit about 350 - 370bhp.



Edited by Mr Darcy on Friday 30th July 15:41

Marf

22,907 posts

271 months

Friday 30th July 2010
quotequote all
2871 isn't the Disco Potato, 2860 is the DP smile

Vixpy1

42,699 posts

294 months

Friday 30th July 2010
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Marf said:
2871 isn't the Disco Potato, 2860 is the DP smile
yes

Get it mapped properly.

You should see 350 - 400 on that turbo at high boost.

Mr Darcy

Original Poster:

1,006 posts

202 months

Friday 30th July 2010
quotequote all
Marf said:
2871 isn't the Disco Potato, 2860 is the DP smile
Oh well. Have to scrap the car then. I wanted the DP

Vixpy1

42,699 posts

294 months

Friday 30th July 2010
quotequote all
Well, you can have a DP, but you would prob only be looking at 330 to 340bhp, and they don't spool much better hehe