I current have a scoobysport BB and OE DP and Centre. I have renewed my insurance and they told me because I have declared the BB I am allowed upto 10% increase in BHP from the exhaust alone without an increase in premium . I am not sure I want to do the DP as I want to leave the DP cat in, so I am looking at a centre + BB.

The car is a MY00 WRX RA (non sti). Assuming the car is 276bhp Anybody think I would get more than 28 bhp from this alone ?

There are no other mods engine wise ie. standard filter etc.

I had a look at the dynos and I am 99% sure I am okay but just wanted to check. I reckoned I would be luckily to get 15bhp nevermind close to 30.

Any comments ?

cheers

chrisp

 

I'd make sure the car doesn't run lean, on the virge of detting...a free flowing exhaust will alter the AF-mixture quite alot.

/J

 

Yep good point, I have a knocklink on the shopping list as well .

 

An air/fuel ratio gauge would be a good idea as well....while you're at it.

I'd reckon power should go up with ~10 real horsies, but the most noticeable increase should be more torque, and more of it lower down in the revs.

/J

 

If it's an RA then it's a Jap import. Jap imports don't need cats for the MOT. AFAIK. U can get the DP as thats where most of the gains are to be made without further expensive modification.

As has been said, u will need to watch the fuelling and keep an ear for det aswell.

P.

 

What a load of old boll*cks some people sprout!

I'm sorry but I totally disagree with Secret agent man

Dont waste your money on an and air/fuel ratio

If u are just changing the exhaust - and you should change downpipe and centersection, to remove all the restrictions in the system - then yes your airfuel ratio will not change that significantly

However if you do anything else like changing the air filter and mess with anything else then you may need the knocklink

The air/fuel meter is a very 'primitive' thing that only mappers need. I can assure you 100% that it is not needed.... People should resign their comments to the muppet section is they are going to spout such rubbish

I have one on my car to aid Bob on the mapping - that is all - I woulod not have one at all otherwise and I have:

VF22 Hybrid turbo
Full free flowing 3 inch exhaust
Front mounted intercooler
Link ECU
Air filter
run 1.5 bar of boost
loads of advance....

In only recently got the knocklink - but that is redundant if you fill up with Optimax

As far as the other comments about bhp/torque goes this is spot on

But please dont waste your money on the afm - you should be fine with just an exhaust

Just to confirm this - I had the det cans on my car with exhaust and filter and it was fine! on an sti5 - this was with Ron 98 though

If you want to save money on the above then put in Optimax then the Knocklink is also redundant....

IMVHO

 

Steve, you complain about people talking crap, and then you come back with one of the most stupid statements of the year.

'The knock link is redundant once you fill up with Optimax'

Just because you fill up with Optimax, DOESN'T mean that you won't get det, you can still get a bad batch of fuel, thus causing det.

Dan

 

No sh*t

Ok - never effected me

My cars still intact

But perhaps I drive too conservatively

 

No problems guys, the knocklink was going on anyway as I have being meaning to have one fitted since I had the car. I now only use optimax and even chucked in a bottle of millers on the last fill up. Previously it was run on Shell and Esso SUL + octane booster.

Thanks for all the advise I think its gonna be a knocklink then centre section.

I know the knocklink is probably a bit over the top as the car is very standard and I always run good fuel but I would rather have advanced warning and back off and get the fueling sorted if its detting.

Cheers

Chrisp

 

Normally I wouldn't react to comments like the ones above... [img]images/smilies/mad.gif[/img]

Facts...
You're talking about a car that's designed to run on jap 100 ron fuel, and has been known to det on your super...and the q's on the quality of the Optimax (remember Craigs detting?) is yet to be found out.
THEN you change the exhaust system, remove the restrictions...would this not increase the risk of higher flow -> leaner mixtures...no?

Yeah sure, if you're driving miss Daisy around town it may be fine, but with sustained boost at higher revs there could be problems. I don't see the bad in checking the AF ratios, I'd even do that before I'd change teh zorst just to be sure that it's running well - hell I'd even go for an EGT gauge instead.

I've modded my car quite a bit myself, and I'm running a link as well (installed by myself) - so I think I know a bit more than the other fella.

MY00
VF24
Link
Scoobysport exhaust
yada yada yada

[img]images/smilies/mad.gif[/img]

/J

 

Dont lose all your toys

I dont agree with your comments - even your recent comments - I'll leave it at that

If you remove therestrictions then yes it does change the parameters - so what!

If u want an afr then so be it - if you've installed the Link, then it is more useful to u. Although your car is fairly standard.

My Scooby is very tame - its the least modded of all the cars I've owned - but I'm totally clueless!

I think people overreact - you here a few horror stories - like no3 big end - I know of someone first hand who has had this problem and it was the result of running ron 95 at 7500 in 5th gear for over 15 minutes and the car detted like hell.

If your gonna do this, or take on a track - then yeah, you need all the safety you can get - and I would agree that a Knocklink is a good option to take - still not convinced on the afr - but I never will be

Dont forget that the standard ecu can retard the ignition to a certain extent when theres bad fuel.

Re the det at high revs - I wont go into that discussion but there are a few people out there who know the answers - so I'm afraid thats your ignorance

 

Chrisp,

To answer your question, it's not unheard of to get gains of 20~30bhp with a full exhaust, most coming from the d/p. As far as your insurance is concerned, I'm sure that any overall gains would come within the 10% (one way or another either way, it would be very marginal, and could change day, to day.

As for some of the other comments:
Steve, the Lambda Link may be crude, but I've said before, used correctly, it's more than able to read AFR under boost conditions. Bob uses it to map not only his customers cars, but also his own.

I would agree that for imported cars, a Knock Link would be far more useful, until such a time as tuning goes beyond an exhaust, and filter change.

One of the things that you aren't taking into account, is that both Jerry, and Danny, both play with their own maps, and in doing so, will be running a lot closer to the edge, than the map you will be running. Because of this, even very minor changes in fuel quality, will show up on their Knock Links, as will changes in air temp, and barometric pressure show up on their Lambda Links.

None of these products are a waste of money, if you are "experimenting" with your car, or are just interested to know what's going on.

For some reason this subject obviously makes you very angry ??? Maybe a Lambda Link isn't a neccesity at Chris's level of tune, but was the suggestion really SOOO bad !!!!!

Mark.

 

By the way, you WILL need your downpipe cat (the only cat you've got) to pass an MOT unless you put a special performance catted centre section in instead - like those available from Power Engineering. Just because your car is an import (like mine) doesn't mean it is exempt from emission regulations. I've seen this discussed at length elsewhere and that was the conclusion.

 

Ok, ok

The suggestion was fine - its another level of safety on the car

Just did'nt think it was particularly practical on a car with just an exhaust change - agree with your comments though

 

Steve and others, just another note.

A lambda link will be your only warning if your car is runnning lean in non mapping related circumstances. Eg if your fuel pump is not up to full efficiency, or injectors have failed, in which case you will run seriously lean and quite easily destroy your engine without you having a chance of spotting it in time.

 

chrisp

No one's mentioned that you should RR your car first! That way you may see that you aren't even getting 276 with SUL, especially if you go to Power Station. They've allowed you 10% on 276 - see what your getting first then decide on the mods.

JMHO
F

 

Yeah

You'd be starting off with about 30bhp in the bank if you get a print from PS - no offence to their place intended at all

Makes me want to modify my car more......!

 

I would go to pts, they gave me 250bhp and 219lbft on my car.

Lower than my old wrx!!!!


is a great print out for my insurance company who accept a rolling road printout for proof of bhp.

Was lucky then that after all my mods on PE, my car made 273bhp.

Interestingly, BHP is the only figure, so a map of 1.8 bar at the bottom tailing to 1.0 bar at teh top, will yield a shockingly fast car with a low bhp output!

 

And i thought that your happy with nearly 350bhp Steve

Tony

 

Yep I should really get it RR another thing I should have done. I should also say that the car has covered an intergalatic 4000 miles from new, must get out more . So it probably hasnt loosen up fully yet, which is why it hasnt been near a RR yet. Not really interested in extra bhp just want the noise and free reving ability and to keep the insurance company happy. The car is plenty fast for me (did I really say that ) and a completely different animal than my old MY98 UK. My old UK always felt like it need another 30 bhp should have had it PPP-ed I guess.

cheers for all the comments

chrisp