I've just spent the last hour practically scouring these threads looking for something I had read earlier, and I'd really not prefer to spend another hour looking.

I think I stumbled across it while I was researching the K&N filter.

I'm pretty sure it was a link to a page that listed what mods yielded what gains, and one that was mentioned was the removal of the plastic engine cover. Due to it retaining too much heat causing the fuel rails to get too hot.

I can't remember what gain it provided and if it's worth it, and am wondering who has removed it for the potential gain.

There is no gain at all, its just a myth. Its more a placebo effect than anything...

I took it off purely because I liked the look of my intake manifold more than an engine cover...but I have heard that its best left on in case of water splash up or something...was in an earlier thread on here somewhere

I think it was the Qld crew who do it mainly because of tropical heat???

It was Knotched, and If I recall correctly, removal netted 2 KW on the Dyno.

It was Knotched, and If I recall correctly, removal netted 2 KW on the Dyno.

...and if I remember correctly, that was after the rails/manifold were heat soaked with the cover on, and the net gain could have been higher if the cover wasn't on at all in the first place.

That's more than the K&N filter provided, so surely it's worthwhile?

Weird. I'd think hot fuel would vaporise easier, thus giving giving bigger explosion, therefore more power?

Weird. I'd think hot fuel would vaporise easier, thus giving giving bigger explosion, therefore more power?

Yeah weird Huh, but the 380 has pretty good fuel atomising jets though. So maybe, Colder fuel = More fuel and colder intake temps help together.

I recalled incorrectly, 2 HP was the figure.


Should find that post again huh.

Here (http://www.aussiemagna.com/forums/showthread.php?52831-The-Search-for-Tuning/page4&highlight=remov+cover) it is.


Well folks,

Back here again after another dyno session on Wednesday 24th.

First up, let me thank Sports for recommending the tuner to me :)

The aim of the session was to find out whether the AFRs from the Romanos printouts were bad (~ 10:1) or really bad (< 10), and whether it was worth exploring the interceptor option. Secondary was to find out what the 90mm US Galant intake was doing for the engine output.

The conditions were reasonably hot; 29C (inlet temp was 28C) and when I started, I had exactly the same setup as the previous dyno run at Romanos (posted in Dyno Charts). I have to state here that the measured output was nowhere near what was measured by Romanos, something Chisholm had warned about. Obviously there are differences in dynos and the Romanos runs were done in cooler weather (10C cooler). This dyno had been calibrated the previous week and seemed very conservative (my car was making slightly more power than a Corolla :sook: ). All the better, as far as I’m concerned.

The tuner did 15 runs to find out what the ECU was doing and to test various configurations including intakes. It was very comprehensive and nothing was left to chance; if a gain was made, it was rechecked again on another run. The car was allowed to cool at some stages but mostly the engine was under a reasonable amount of heat soak which means the gains were real and the minimum I could expect.

Firstly the AFRs were checked and in contrast to the HP output, Romanos were spot on, the AFR was 10:1 but didn’t go any lower. The tuner was able to artificially raise the AFR to 12 maximum and keep it there which realized a HP gain immediately.

Results (all results are AT THE WHEELS and repeatable on the day) :

1. AFRs held to 12:1 + 10 hp

Comment: Normally car would be expected to run 13.5:1 so another 5 hp would be expected if the AFRs could be elevated to that level (interceptor :P )

2. Remove plastic engine cover + 2 hp

Comment; This was a repeatable gain and is due to excessive temps around the fuel rail and cam covers held in by the cover. It was also achieved after the engine was heat soaked so it’s possible another 1 or 2 hp might be there if the cover had never been fitted.

3. 90mm inlet fitted + 13 hp

Comment: In context of the test, the most major gain! The power and torque graphs left the standard 68mm inlet in the dust in all parts of the rev range. Nothing more to say.

4. 90mm inlet and standard air filter removed + 4 hp

Comment: Gives an indication what effect a K&N filter would have as my tuner said, from previous experience, it would take away around 1 hp; so gain with the K&N would be ~ 3 hp expected.

So, with the 90mm intake fitted, K&N air filter, engine cover removed I can expect a total gain from my previous config of , say 18 hp.

With an interceptor fitted, I could expect a gain of 33 hp minimum with all mods.

On the day the car achieved +19 hp on the dyno with no airfilter and no AFRs adjusted.

If I proceed with an interceptor unit, I’m looking at 190 hp total ATW on this dyno.

(Don’t forget; no extractors; two cats on each exhaust manifold still there.)

Sorry... i have chosen to delete this post.

Here (http://www.aussiemagna.com/forums/showthread.php?52831-The-Search-for-Tuning/page4&highlight=remov+cover) it is.

Wicked. Thanks man!

How did you find it though?

I scoured these threads and tried a number of words/combinations in the search engine!

15 dyno runs in one day, in those ambient atmospheric conditions is pretty demanding...

I dare say the potential for engine damage is quite possible as well.

Hope he knew what he was doing.

I had it dynoed about six months later by Chip Torque when they tuned the EXede. The rating in my sig was the result.

Sorry... i have chosen to delete this post.

I think I'll be removing mine when i get home this arvo.

Pity though, coz I really like the look of the cover.

How many of you guys have actually removed the cover?

I have for now as I like the performance gains, but the engine looks butt ugly without it though.

I'm in two minds again.

'I have for now as I like the performance gains'
What improvement have you noticed?

I had mine off for a while but put it back on and didn't notice any difference... so I left it on.

I took mine off about three months ago when I noticed how hot it got due to the extractors. Definitely much hotter then before the extractors. Seemed to me it was trapping a lot of heat underneath it, not good for the fuel rails etc. And the intake manifold seemed to be hotter than before as well. Took it off as a test, and it felt like the under bonnet temps dropped a fair bit. No scientific measurements, but it def seemed cooler with it off. So I've left it off ever since. The slightly untidy appearance doesn't bother me, and I've been mucking about a bit with the front bank injector lower spacers and spark plugs anyway. Spark plugs arrived today, will be fitting them and new injector spacers on Saturday, with any luck the annoying tick tick will be banished.

KJ.

Sorry... i have chosen to delete this post.

'I have for now as I like the performance gains'
What improvement have you noticed?

I haven't noticed anything, but there is a quantifiable gain of at least 2hp proven by the dyno results posted by Knotched.

I'm kinda wanting to get every kw I can, but don't know if the downside of having to see that engine when I pop the bonnet is a fair price to pay, and was wondering what everybody else here had decided on.