Slow 16v?

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

As some of you might know i changed 16v's the other week. Only thing is this one seems a bit sluggish compared to the old one. On my private test track ( Wink

) the old one hit 110mph easily and keapt going, this one struggles to hit that.

So far i've cleaned the TB, cleaned the ICV, changed the CTS, HT leads are fairly new, checked the spark plug condition and gap

Granted the old one had a decat, but these cars should hit 130mph as standard and a decat couldnt make that much differene? Could it be i just have an engine thats a bit down on power?

Thoughts?

Cheers

Level 1 User Joined: 18 Apr 2005 Posts: 26

Id have to agree with you on that one mate, the blue one feels alot faster throughout all gears then the red one did. Wouldnt have thought decat etc would have made that much difference either! Strange!!

Site Subscriber Joined: 05 Apr 2004 Posts: 1141

Sounds a bit silly but are you sure the throttle is opening fully? The pedeal on the blue one feels a bit heavier then that of the red one. I think the blue one rev's more freely and the cam shift is a lot more noticable.

Have you fitted an induction kit to OCM? Checked the cold air feed into the airbox isn't kinked / blocked / full of mud?

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Aye, checked that the throttle was opening properly, the IK didn't make much of a difference compared to the standard airbox.

Site Subscriber Joined: 29 Jan 2005 Posts: 1108

A decat does make a hell of a difference I think! I put my de-cat on a few months ago and noticed a definite improvement in the lower revs, and also when ur revvin the arse off it.......so basically all round it's better. So anyway, on saturday just gone, me & a mate put my cat back on cuz I got my MOT next week and......it's like a different car. It really feels like something's holding it back y'know. Feels like somebody's got their hand over the back of the exhaust or something.....something restricting it. So could well be the de-cat that's makin the difference. Unless my cat has got a badger stuck in it or something lol

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

some of them are just dog slow and others are rapid.

Fact of life!

Site Subscriber Joined: 01 Mar 2004 Posts: 458

yep my old engine struggled to hit 125 this one i've had obver 140 reading on the clock! acceleration is different too just luck of the draw i guess

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Aye ,looks like it; just wondering if there was anything I could do...

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

change the engine

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

stan wrote:

change the engine

Without going that far! Can somone explain why some are slow and fast? Bad casting? not quite well sealed valves? low compression or what?

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

Manufacturing tolerences. bore maybe 0.01mm larger on yours and therefore have less compression. if the pistons were 0.01mm smaller, then things are worse.

all have what u have mentioned will contribute to low power. as will the fact that its a 10/15 year old engine that has likely had the nuts ragged off it most of its life

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

true, i guess a low miler (87k) aint everything!

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

im still trying to decide how my chamade stacks up against the hatch. The hatch seems a lot faster, but it does have a decat and straight through exhaust. Could be just the noise making it seem faster. The chamade's clutch is nearly finished too, which doesnt help trying a quick setoff.

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

-Well, I changed the spark plugs today, got some NGK dual electrode jobbies, not perfect, but they were only 7 quid and must be better than the bosch ones that came out.

Also did a compression test, after a few goes I got 198-209-200-189 . Not too bad, I dont think...

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

20 PSI between 2 and 4 isn't healthy!

But I suppose its tolerable.

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Thats either down to valve seals or rings? Well, there isnt much im gonna do about it, althought that should be the reason for its slowness?

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

it could a be a reason for its slowness but tbh mate its more than that.

At the end of the day my 1.4 would pass 110 easily as would georges.

In fact project Y with its raging 60 horses goes beyond 110. Dunno how much further cos 110 was just after I left the mot station and had to slow due to traffic.

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Aye, had faster than that out of my TD

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

sell it

but make sure the fuel filter, and air filter etc ain't decades old

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Sell it?

I've only just bought the damned thing!

Site Subscriber Joined: 07 Oct 2004 Posts: 2281

It's weird, sometimes my car will get to a 100/110mph easily, yet other days it struggles to gain any revs at 75mph, it's weird!

This phenomenon also extends as far as certain roads. On the M67 OUT of Manchester, it picks up well, gets up to 90mph, then near the end the speed gradually decays to about 75/80mph with my foot down, but the weird thing is it happens EVERY time, on the same road, in the same place, regardless or day/time.

What's even stranger than that is when I'm going the other way on the M67, going back into Manchester, she loves it and will pull hard up to 110mph, and this happens every time as well.

Chris can vouch for the inconsistency on mine, on our little excursion up to L. Lomond I had my foot buried in the accelerator on a dual carriageway and it wouldn't go past 90mph, Chris commented that was pretty sluggish and even asked me if I had my foot down.

Yet the next day, when I left Glasgow, she easily managed 114mph (incidentally, the highest speed I've had out of her, see photo!) and she kept it up for the best part of 2 hours as well!