Since this is a topic that always comes up I thought I'd stick in my 2p's worth.

All the figures I'm sticking in here come from a road dyno and are not accurate, they are however consistently repeatable which makes it usefull for seeing how mod's work.

The car is an MY99 uk with full de-cat, (now) V1 Grouppe-s headers, Gems, TD05/06, APS TMIC and HKS induction kit. 1.3Bar boost (plus all the usual things).

Before the headers I had an indicated 340bhp at 6k rpm, with torque leveling off at about 3.6k rpm (330nm peak 4300rpm), full boost at 3100rpm.

Now I get 400bhp at 7k rpm, with torque leveling off about 4k rpm, (355nm peak 5300rpm), full boost by 3300rpm.

Because of the only minor increase in lag I'm assuming I had a slight leak in the standard headers (nothing noticed when removed).

So a huge increase in power with no mapping changes as yet.

On the 1/4 mile however power only got to 350bhp in 2nd and 3rd, dropping to 320 in 4th (timing retard due to AIT above 40deg). This gave a 13.4 @ 108mph, gental launch and easy shifts though (2.5sec 60ft).

Interesting results since I wasn't expecting to gain this much, and one more thing, I'm definetly NOT claiming to have a 400hp car just in case one of those arguments starts

 

good on ye dave well impressed there

 

I would have thought it had more than 340bhp with an TD05/06 @1.3bar anyway?

13.4secs 1/4mile....watch out for them tek'd TD04s

Bob

 

does that mean i owe you a pint as i haven't had mine on the rollers yet plus im thinking of putting an STI8 intercooler on mine

 

Don't worry, If i see any sneaky looking TD04's I won't launch like miss daisy

In fact then I'll definetly loose when I leave my clutch at the lights

Nah not quite yet, the actual number was 399.9. I'll have to wait for a colder day

However I'd be happy if it was a realistic 350. It does look like your original aim could well be on...... I'm already looking for a tastey sauce to serve with my hat

Oh and thanks dave, at least one of us has to keep the RB5 name going right

Dave

 

w@nk

 

how do you know you'r not running much leaner now? Since the GEMS doesn't use a MAf sensor, and your breathing has improved, you need to get the thing remapped or at least checked as safe. If you are running much leaner this may explain the massive increase in power, but may also lead to melted pistons if you are not careful.

Paul

 

It had crossed my mind. I don't get a single green on the knocklink and after a wee thrash the turbo wasn't glowing red. According to the lambda link it's richer around town, but it stops working once the probe gets hot. I suspect it was fried by anti-lag.

I assume I would run into a bit of knock if things were reaching piston melting temps?

Dave

 

you may not get knock if the ignition timing isn't too fierce. And playing with ALS for extended periods of time is foolish.

Check it out before the engine checks out, permanently.

Paul

 

Dave

Can you not fit the Lambda in the headers ( like the older classics ) instead of the downpipe, so any anti-lag antics don't affect it?

Does the GEMS use the Lambda signal or is this just for your LambdaLink ?

 

I would think just turning the ALS off with the switch is easier.

Paul

 

Paul

Indeed...

 

Well with the new headers on it's less of an issue. Even midler than before, no bangs at all, just a rumble and noticably better reponse between the gears. I only really use it on the quarter mile anyway these days, which is not very often (fried probe due to the 'novelty factor' ).

However with a bit more testing I'm not so sure about the fueling anymore so the car's getting garaged for a while.

Dave