118 replies to this topic

[Nev]

NA airbox is bigger and better flowing than the turdo's. It's from a V6 Vectra.

Pulling 300 BHP worth of air through a 200 BHP airbox will certainly induce a vacuum on the inlet side. The SC will have to work to overcome this. Also, I wouldn't be surprised if the airbox was a compromise/restriction on the Vectra in the first place.

Edited by Nev, 16 July 2015 - 03:33 PM.

[Rosssco]

How do you define a "200bhp" airbox..? The airbox could flow 200 or 500bhp for all we know...

 

The filter is the primary restriction, after that there is the upper section of the airbox, then (in SC applications) a relatively short run of pipe to the TB. As I said, what is the size comparison to the like DH airbox which is suitable for ~400bhp engines?

 

Plus I wouldn't be fitting the NA airbox to eek out the last few BHP, so if a couple were lost, so be it..

[Nev]

It's fine if you don't care about losing the extra few BHP, I was merely making a point to readers that the OEM airbox becomes more of a restriction on a car that is making +50% power, no matter how many bits of front/side panel you cut off it.

Edited by Nev, 16 July 2015 - 05:19 PM.

[MAXR]

Nev,

 

Did you end up fitting your DIY filter housing & twin paper filters? Did you draw any conclusions?

 

Any photos?

[Nev]

Nev,   Did you end up fitting your DIY filter housing & twin paper filters? Did you draw any conclusions?   Any photos?

Yes, from memory I got a dyno proven +50 BHP odd and roughly +75 ft/lb of torque. When I tested it on the road (using the Courtenay map at that time) I very nearly did a wheely due to the poor torque control on that map; it was genuinely frightening as I lost steering for a second or 2. That whole spring + summer the car was almost undrivable on WOT and forced me to switch ECUs. Pictures and write up of the DIY airbox are on my website: https://sites.google.../07---update-26 Someone else in Germany did something similar and got +30 BHP from a TC'ed car that was previously making circa 340 BHP.

Edited by Nev, 16 July 2015 - 06:06 PM.

[Andrew aka Stuwy]

just for reference on my old mans VXR8 with its 400+ N/A bhp it sill has a paper filter and the air box is not much bigger then the n/a one, the pipework is 10/15mm bigger though.. next time I am at his and if I remember i'll grab a pic.

 

 

BUT to take from that I am only running 250bhp.. A standard air box will not be much if any of a restriction for me.

 

also I cant put my air filter in the boot

 

Edited by Stuwy, 18 July 2015 - 10:26 AM.

[jackturbostage4]

Stage4 turbo is a real scary weapon .

[XE-VX]

How many 600bhp turbos are kicking around and not jacked up every other week? It takes a fair bit more than internals and a turbo to make even 340 in a tubby. Same goes for the sc, however the new Saab engine will be safe at 340 without major engine work. Out the box to get a stage 4 turbo you'll need to spend £6-8k to make 320-330bhp. £7-9k would see you with a forged SC car being able to reach 350-380. Horses for courses and there's pros and cons for both. The good news is either of them will scratch that itch, but you need it test both to find out which.

I know a vxt with a z20let with 412bhp with stock internals. It is very reliable and drivable

[Zoobeef]

You're all cheating.

[Nev]

How many 600bhp turbos are kicking around and not jacked up every other week? It takes a fair bit more than internals and a turbo to make even 340 in a tubby. Same goes for the sc, however the new Saab engine will be safe at 340 without major engine work. Out the box to get a stage 4 turbo you'll need to spend £6-8k to make 320-330bhp. £7-9k would see you with a forged SC car being able to reach 350-380. Horses for courses and there's pros and cons for both. The good news is either of them will scratch that itch, but you need it test both to find out which.

I know a vxt with a z20let with 412bhp with stock internals. It is very reliable and drivable

Interesting, who's dyno was that done on, and what ECU and who mapped it please?

[Nev]

You're all cheating.

Haha, you cheat by stripping your car out by 150 KG ! LOL

[XE-VX]

[quote data-cid='1805235' name='Nev' timestamp='1437343725' post='1805235']How many 600bhp turbos are kicking around and not jacked up every other week?


It takes a fair bit more than internals and a turbo to make even 340 in a tubby. Same goes for the sc, however the new Saab engine will be safe at 340 without major engine work.


Out the box to get a stage 4 turbo you'll need to spend £6-8k to make 320-330bhp. £7-9k would see you with a forged SC car being able to reach 350-380.


Horses for courses and there's pros and cons for both. The good news is either of them will scratch that itch, but you need it test both to find out which.[/quote]
I know a vxt with a z20let with 412bhp with stock internals. It is very reliable and drivable[/quote]
Interesting, who's dyno was that done on, and what ECU and who mapped it please?[/quote]

A&M conversions dyno, they mapped it them selfes on there development vx, ecu is standard.

[ArticMonkey]

That's sounds great, but why is everyone forging and rebuilding their turbo blocks if it can apparently handle over 400? Still, you'll be forking out for all the other parts like turbo and exhaust and I'm sure the head and crank would need porting/ balancing.

[XE-VX]

No head work, no internal modifications. Hybrid turbo, 630 injectors, 3 inch exhaust etc. I suppose it's all in the mapping side.

[ArticMonkey]

Playing devils advocate here. I wouldn't like to quote what the engine can handle but I'm taking a guess vauxhall didn't over spec their engine so it can take more than twice it's normal power. Maybe the engine did have furver modifications to the engine or the mapping/dyno is very, very complamentry with the figures. Turbo owners have been playing around with their engines for over a decade now, and if it was as simple as injectors/turbo/ exhaust with a magic mapper, you'd think there would me more on the road running near 400bhp? I'm sure people like Nev and Mbez would like to see some data and hard evidence as this would help in their builds, along with other owners wanting to upgrade.

[stu8v]

Its a bit like a hand grenade with the pin pulled, sooner or later it will go bang........

 

If you correctly spec an engine for power and longevity it cost, it costs a lot.

 

Tuning Triangle.

Cheap, Fast, Reliable.

You can only have two of the above.

[mbes2]

I know a vxt with a z20let with 412bhp with stock internals. It is very reliable and drivable[/quote] Interesting, who's dyno was that done on, and what ECU and who mapped it please?[/quote] A&M conversions dyno, they mapped it them selfes on there development vx, ecu is standard.

 

Just a road car or track ?

 

I think on the road it would last as not under heavy use, would still limit the road life 

[Nev]

I wonder which brave soul will be the first to compound charge and get the best of both worlds (in  theory!). Lee...

Edited by Nev, 20 July 2015 - 09:57 AM.

[XE-VX]

I can assure you there is no bulls*it figures from the dyno it very accurate and calibrated correctly with using new standard power cars coming out the same power as stated from manufacturers. There is other modifications too, but no internal to engine. This tunner is very capable he knows the Vauxhall components very Well and is very familiar with the engine range. Just take a look at his manta all built him self and mapped by him. Surely his experience and expertise should not be questioned  ImageUploadedByTapatalk1437395605.446307.jpg   108.82KB   15 downloads

[stu8v]

No amount of good mapping can make metal things stronger, just saying like.

 

Not doubting the achievements btw.

 

 

Any better pics of the Manta?

 

Its one thing I'd easily swap my VX for :-)

Edited by stu8v, 20 July 2015 - 12:49 PM.