recovering lost BHP

[Eiger]

G'day

Simply put - How can you recover lost bhp?

The engine in question is a 2.5na living inside my '86 Lux - she's done just over 200,000 miles and still goes strong; pulls nicely, got good acceleration, and cruises smoothly, but I'd like to restore bhp and then eek what I can out of this engine.

All advice welcome
please don't say buy a Turbo ;-)

 

[zcacogp]

ORIGINAL: Eiger
please don't say buy a Turbo ;-)

Buy an S2. []

Where have the horses gone? At a guess, valves will be leaking a little as will the pistons. The only answer for that is a head re-build and possibly a re-bore. Both expensive.


Oli.

 

[FistsOfHam]

Getting the injectors cleaned probably wouldn't go amiss either. That and checking all of the ignition and fuelling components are working properly.

 

[Suffolk944]

How many horses has she lost ?

 

[homesea]

When was the last time it had a service?
Just a simple oil/filters/plugs can make a difference.

 

[944 man]

Jon: itll be most of them; according to the rabid mentalist on TIPEC...[]

 

[Eiger]

I dunno how many she's lost - I've not driven another 944na or done a dyno yet, which I plan to do once the usual service items are done. Not being a mechanical master I'd like to know what direction to move in to get this motor in great shape. It does feel perky tho

 

[Suffolk944]

ORIGINAL: 944 man

Jon: itll be most of them; according to the rabid mentalist on TIPEC...[]

Ah I have not seen that - think I will hurry over there now and take a look ! []

 

[944 man]

Sorry, there isnt a current thread: but if you ask he will start again. JJ is his username, I believe.

 

[MRGT]

Now now guys, it's a bit unfair to have a dig when he's not here to respond.

Anyway, back on topic.
I suggest using a reputable dyno if you feel you are missing something. When you have the results you will be better placed to know what to do nex.

 

[944 man]

On the contrary: its usually the best way!

It is nonsense though and I have told him so.

 

[DivineE]

I couldn't believe how much crap had built up on the back of my valves by 140k miles. If you want a near free option I'd just clean up the valves (maybe re-grind the valve seats if you can), put it back together with a new gasket for peace of mind, sonic clean the injectors, replace the plugs, replace the dizzy cap and rotor arm, probably the HT leads to complete the set. So long as the bores are not scored I bet you could get it back to 'almost' new -maybe even slightly more than new hp for a few hundred pounds worth of consumables.

Regards,

Ben

 

[barks944]

Do ignition coils degrade with time?

 

[zcacogp]

Fail occasionally, yes. Degrade? I don't think so.


Oli.

 

[pauljmcnulty]

Simply put - How can you recover lost bhp?

Hi Stephen,

What makes you think you've lost any horse powers?

Barring any major problems, it's a pretty unburstable engine. The weak points are the ignition parts, with the leads, rotor arm and dizzy cap often well past their best.

There's not a lot you can do to improve the Lux from a sheer power point of view, other than going mad and supercharging it or slapping in a V8. It's a very well-balanced car, IMO more suitable to having fun at legal speeds in the UK than any other 944. I know it's controversial, but if you live in a part of the country where there are speed cameras, mobile speed checks, unmarked cars or general traffic, then a good Lux on it's smaller tyres is far more "nimble".

I'd start with a proper service, then look at a throttle-response cam from Porscheshop. The one fitted to the Lux is an economy-focussed part, and many people find the replacement one gives the car a far more responsive feel. Then, I'd spend the money improving the brakes and suspension, if it's not new it's tired. Then, consider advanced driving lessons; it's not patronising, anyone who's ever seen our own Nick Fearn driving in real-life conditions will confirm that driver ability counts for far more than the BHP figure a car kicks out.

 

[dirtydirtyharry]

ORIGINAL: pauljmcnulty

Simply put - How can you recover lost bhp?

Hi Stephen,

What makes you think you've lost any horse powers?

Barring any major problems, it's a pretty unburstable engine. The weak points are the ignition parts, with the leads, rotor arm and dizzy cap often well past their best.

There's not a lot you can do to improve the Lux from a sheer power point of view, other than going mad and supercharging it or slapping in a V8. It's a very well-balanced car, IMO more suitable to having fun at legal speeds in the UK than any other 944. I know it's controversial, but if you live in a part of the country where there are speed cameras, mobile speed checks, unmarked cars or general traffic, then a good Lux on it's smaller tyres is far more "nimble".

I'd start with a proper service, then look at a throttle-response cam from Porscheshop. The one fitted to the Lux is an economy-focussed part, and many people find the replacement one gives the car a far more responsive feel. Then, I'd spend the money improving the brakes and suspension, if it's not new it's tired. Then, consider advanced driving lessons; it's not patronising, anyone who's ever seen our own Nick Fearn driving in real-life conditions will confirm that driver ability counts for far more than the BHP figure a car kicks out.

Sounds like good advice to me.

ps, are there any decent reviews on the throttle response cam. Im keen to improve the power of my n/a lux in the most economical and cost effective manner. I had planned on just getting it chipped but I may be swayed by the throttle response cam if the verdict is good. []

 

[pauljmcnulty]

are there any decent reviews on the throttle response cam. Im keen to improve the power of my n/a lux in the most economical and cost effective manner. I had planned on just getting it chipped but I may be swayed by the throttle response cam if the verdict is good.

In six years I've only seen a couple of people who've not felt it was worth doing. It does make the throttle pedal more responsive, essentially it's a circle rather than an oval cam, so there's no dead spot at the top of the pedal travel. It's been commented that it makes the car jerky to drive, but I think that's possible down to the change in feel. S2s and Turbos have this as standard, and I've never found anyone wanting a "slow-response" cam.

Porscheshop were doing a free-fitting offer at the open day last year, and Ian was confident enough to offer to fit the old one back for anyone who wasn't happy with the improvement. It's interesting that some companies, like Porscheshop and Promax (with their chips), are prepared to stand behind their products in this way.

 

[Mike_Pollock]

The throttle response cam is great.
Mine had one fitted when I bought it, but when I drove a very similar car with the standard cam, I was amazed how "slow" it was.
£15ish (I think) = very good value!
Mike

 

[homesea]

New cam on the throttle = 20bhp extra []
Well thats what my old one felt like on my lux just before the engine blew up. (Cam was nothing to do with dead engine, that was the oil pick pipe cracking in half at 145ish MPH [:'(])

 

[Northern924]

Just 'upgraded' to a '44, and this one came with a throttle response cam.

I previously ran an 88 924S, same bhp as the 44 and I can tell you it does make a big difference, car is much more responsive, not expensive but along with whats been mentioned about a thorough service you should make it feel a lot better