84 replies to this topic

[clipping_point]

Is it though? The Viper has a carbon surround inside the cone, the aim of which is to shield the air from the heat of the engine - something not done by the standard airbox. With the air feed for the Viper coming from the vent, I would have thought this would result in cooler air than that provided by the standard airbox?

I think that the heating effect through the plastic wall is very limited and will not affect the power output. Anyone who says so will be a liar. You have a radiation heat from the engine but not much out there at the intake. The plastic box wall itself serve as a good insulation.

All cars I know of have a standard intake of cold air arranged though a snorkel. The heating of the air through the ducting can be calculated, but will be small , I think.

Or as "dude" put it (yesterday):

"I have tested different filters on RR but haven't found a single HP compared to a standard SAAB 900 (paper) filter in an airbox with a cold air intake (snorkel)"

(sorry dude )

Edited by clipping_point, 23 March 2004 - 06:13 PM.

[LewisT]

so what are you suggesting here???

[clipping_point]

1. Remove the pre-cat 2. Don't do anything to the induction 3. Perform a AmD remap 4. Remove ALL camber shims in front, and ONE int the back suspension ..and you will have 168-170 HP and terrific corner speed for £295!!!

[Thorney]

Pretty much agree with clipping point.......the airbox isn't the issue its the cold air feed. The Viper worked really well at top end but that is/was all due to cold air infrom the intake stuffed into the side vent, the air didn't stay long enough in the airbox to get heated up to any extent. The downside is that the vent attracts all kind of crap from the road (and water) and that failed the AMM. Either than or its that flow of air issue which I'm dubious of but could well believe it.

[DJG]

I wouldn't get all hung up on performance, the VX is a quick car, I came from a BMW M coupe, 325 bhp and 0-100 in around 11 secs. At the time my brother was driving a 2.5 Boxster and there was very little between them up to 60/70. Powerful cars really come into their own at higher speeds i.e. 100+ but how often are you going to race at speeds well over a hundred if you value your license? Anything hitting 60 in the 5s is plenty, it's the corners that count!

[LewisT]

Can i confirm, removing the precat, it doesnt affect any vauxhall warranty, and it doesnt stop the car passing an MOT. Also does the AMD chip get noticed when the car goes in for service and alike, again affecting the warranty. Do you not feel a 1.precat removed 2. viper induction 3. amd remap would produce more than just precat and amd remap. I realise what your saying is that it might be so insignificant an gain for £250. I heard of a man on his turbo astra putting a pipe from the bonnet vents direct to the top of the air box. bit of drilling and alike, but he says it got cold air in and improved performance. Its cheap to do, and all you need is a pipe to the vents on the VX. cold air at any speed gets sucked in, or so he says. anyone any thoughts

[Jase_MK]

I don' thtink you'll notice much difference (power-wise) whilst sat in the driver's seat with a Viper. But like I said before, it's all about the whole experience and the sound it makes makes you feel like you're driving a sports car and not an Astra. The standard engine sound is a bit dissapointing I think. Some might find it a bit loud and annoying but everyone's different I guess. Don't get it thinking it's going to give loads more power though. I did feel it pulled through the revs a bit better with the Viper but that could be my imagination...

[P11 COV]

I've got the sports exhaust, add a cheap induction £60, AMD remap £300, remove the pre cat (free if your'e into DIY) and you have 170+ BHP. - thats 16% hike in power from standard.

Mmmm..personally I think this is a little generous .

Normal remaps offer between 7-12 bhp but with these figures, you're expecting more like 15-20 bhp from a remap to achieve the 170+ mark...without Cam work and the rest, I think you'll struggle (IMHO).

Courtenay reckon you'll see about 30bhp increase with their CS3 package which includes full exhaust sys inc. sports cat (not just back box) + Cams, airbox mods, filters & remap.

I don't mean to question you P11 COV, if you have this then lucky you, I just don't think 170bhp is the normal return from just backbox, remap & induction

Hey hang on chaps i'm only quoting the paperwork from the rolling road!!

Pre remap (so thats just piperx induction, VX sports backbox and pre cat removed) was 154.1 BHP.

After AMD remap 171.5 Thats 17.4 BHP increase if my math is right.

OK weather temp miles etc may have a bearing on the result overall but this is a before and after figure on the same afternoon.

It'll be interesting to get comparisons on minime's RR day in april.

[PaulCP]

Glad to see that some of you are now realising that numbers count for nothing & that it's how the car drives & feels that really count. Mine now has the full AMD package but with a Regal exhaust & dbilas intake. After trying both Regal & AMD the one thing that is very clear is the different approach to the remap by these 2 organisations. The Regal map concentrates on low down power and low down torque whist the AMD map, quite rightly with revisee cams concemtrates on power further up the rev range. If you take a look at the AMD RR day results you will see that my car was giving much more power low down with max torque at 2500 (ish) rpm but started to lose out above 4000rpm to the others tested that day. The car was very tractable on road and with the extra mods there is still now less power low down but boy does it take off at 4000-4500 rpm. Depends what you want but at the moment i have no regrets at the route i took Paul

[cheeky_chops]

Get some miles on these cars chaps...it DOES make a difference.

I said this at xmas!

I've got 27000 on mine now and i'm gonna whoop all you cam/gas flow 100miles a year boys at the RR next month *




* except paulCP with his Dbilas manifold

[cheeky_chops]

Just wanted to add that its not just power... No more power mods to my NA(unless its cheap) My next mod (either na or T ) will be wheels - lightweight, strong and different tyres. Will let you corner/grip faster/harder esp in MK! and brakes - discs, hoses, fluid, pads. Either way, wanna throw Mrs chops around to the limit

[Duncan]

Either way, wanna throw Mrs chops around to the limit

Sounds like you need some decent rubber. Don't want to risk an accident.

[clipping_point]

Can't believe the guys who pay Scared stiff to remove the camber shims for a meaty £300, and afterwards DON'T KNOW THE SETTINGS THEY HAVE. This means they have to do it all over in a couple of years when they wanna do an wheel alignment. Instead it is a simple mod you can perform at your home. And save the £300.

Edited by clipping_point, 24 March 2004 - 07:54 AM.

[Jim_Cross]

Clipping_point - Scared Stiff mark their settings on the car with a paint stick, so it's just a case of realigning and not taking all the measurements again. Also, it's £140, not £300!

Edited by Jim_Cross, 24 March 2004 - 09:18 AM.

[caleebra]

Instead it is a simple mod you can perform at your home. And save the £300.

Sounds like a good basis for a How To / FAQ clipping_point!

[clipping_point]

so it's just a case of realigning and not taking all the measurements again

OK, is this true? I thought the idea was to improve the handling. Nevertheless, Ricky2772 has inspired me to my mods, and he is the fastest guy around the Ring in a VX220, so what works for hom, works for me.

[Jim_Cross]

No, what I meant was, they have come up with their own setup by testing various settings on VXs. This setup is different to the factory geometry. When they make this change (which does include removal of a lot of the front shims). They then paint-stick on the settings, so that if you do need to have a re-alignment, then know what to set it back to.

[clipping_point]

Dunno what you mean by paint-sticking it, but in sweden I can get a computerized alignment measurement performed for £10, so I would check it!

[Jim_Cross]

Paint-sticking is basically painting a line on the suspension components to mark the alignment, as a reference for where the geometry should be set.

[garyk220]

I presume Scared Stiff at least check/alter; - front: toe, camber and castor - rear: toe and camber A full set-up would also require the front and rear bump steer to be checked/altered. Every car seems to leave the factory with different settings, so while removing the shims may produce optimum camber settings on one car, it does not guarantee the same on another. This would require at least 3 to 4 hours, with a 4 wheel alignment machine, so £140-150 seems pretty good value to me.