Bogging at 4000 rpm

Post by **DARK STAR** » Thu Jun 08, 2017 8:57 pm

Unfortunately I rarely extend the car nowadays but I couldn't resist putting a modern GTI boy racer in his place the other day.
Luckily it was in town so when the engine bogged at 4000 rpm I was far enough ahead and he was't going to go any faster

I think (hope) this problem is due to the appalling state of the air filter, which is after all 25 years old

So, after extensive research on K&N's site I thought I'd fit one of these (56-1360).
It is for twin Weber 45/48 DCOE's so should flow enough air ???
Difficult to calculate the volume because the inlets on the injection are square, as is Ford's wont and everybody else's are round

I need to get it right first time because the thing costs a fortune ...

Post by **efi_sprintgte** » Thu Jun 08, 2017 9:23 pm

Is it for your 2.9?

Post by **DARK STAR** » Thu Jun 08, 2017 10:06 pm

Yes, sorry, should have said ...

Post by **DARK STAR** » Fri Jun 09, 2017 7:17 pm

Nobody in a position to comment?
Please!

Post by **scimjim** » Fri Jun 09, 2017 7:21 pm

Not without a pic of your AFMs and spec of filter. Are the AFMs mounted at the wing, which way round and how far apart? If the filter will physically fit I reckon it should flow enough (guess from pic only).

Post by **DARK STAR** » Fri Jun 09, 2017 7:29 pm

Meters are mounted on their sides, not sure how far apart but I can modify the filter housing.
It WILL fit

Thanks Jim

Post by **efi_sprintgte** » Fri Jun 09, 2017 9:32 pm

My 2.9 had pipercross air filters with the square flange and bolted straight on.

Post by **DARK STAR** » Fri Jun 09, 2017 10:08 pm

Filters plural?
My airflow meters are mounted too close together ...
The present foam filter is Pipercross but all hacked about for the square inlets, I want something more elegant

Post by **scimjim** » Fri Jun 09, 2017 10:23 pm

Mine was appalling and I cleaned it but never got round to replacing it

Post by **efi_sprintgte** » Fri Jun 09, 2017 11:02 pm

DARK STAR wrote:Filters plural?
My airflow meters are mounted too close together ...
The present foam filter is Pipercross but all hacked about for the square inlets, I want something more elegant

Yes, it was a kit for a XR4x4i. One nice neat filter per AFM.

Ran 200bhp with that set up fine (the restriction was the AFM themselves)

Post by **DARK STAR** » Sat Jun 10, 2017 7:05 am

Yours is neat Jim, is it an Edelbrock?
Do you remember the model?

Post by **scimjim** » Sat Jun 10, 2017 8:30 am

I don't Chris - but it wasn't Edelbrock, perhaps an old pipercross?

Post by **DARK STAR** » Sat Jul 01, 2017 3:14 pm

A partial result, now it is just a bit hesitant at 4 000 rpm.
It is much prettier though

Next up, I think the spark plugs, which are not as old as the filter but may be a bit tired.
I have a set in stock for some reason (perhaps I was already going to change them years ago ...)

Here's one I prepared earlier -

Post by **DARK STAR** » Sat Jul 01, 2017 3:15 pm

part 2

Note the genuine Daimler SP250 bonnet stay

Post by **DARK STAR** » Tue Aug 29, 2017 6:40 pm

New Bosch plugs fitted.
The engine is now more supple at low revs - and doesn't want to go over 3500 rpm

Before it accelerated ok up to 4000 then it was as if there was a rev limiter cutting it.
Now it is reluctant to accelerate hard and won't go over 3500 unless I go gently.
Effectively it is the opposite to Vert Soleil which runs ok at high revs but won't idle

I am getting tired ...

The Scimitarweb Forum