Max boost with stock downpipe?

[turbotoaster]

well the issue about the 399 was at 11.5afr i already hit 98% injector duty at 15psi of boost on stock twins with a big streetport and made 360bhp flywheel, saying that i was getting high intake temps so i know that will kill a bit of power

but we shall see as ill stick it back on the rollers with my big cooler and 850c primary to see what effects its made

[wiggman2030]

Thanks for all the feedback. I\'ve decided to fit an HKS downpipe. Also I\'m going to put in some 1680cc injectors with a new fuel pump, regulator etc. After this has would 400bhp be out of the question, sticking to a maximum 1 bar boost?

[turbotoaster]

i think you will struggle to hit it with 1bar of boost, probably looking at 1.1bar assuming everything is flowing correct and your streetport flows well

[wiggman2030]

I got the engine ported by Steve Rivetts, He did someones rex with the same porting as mine, he got it dyno\'d at 360bhp on .75 bar boost with a similar setup to mine i\'m hoping that I get good results like that. :wiggle

[turbotoaster]

yeh steve built mine aswell, you have the large port, basically the one slightly smaller than mine.

i know the car he is on about aswell, you may need to get an ignition upgrade around 360bhp, ive got that power graph if you want to have a look at it.

if your staying on the twins or keeping power below 550bhp on a single in the future then just get a hks twin power.

Im not sure if your gonna need one yet, depends on what your stock coils are like.

Also it depends where your having it mapped aswell, you going reworx?

[wiggman2030]

Yeah the graphs would be good, my email is wiggman@hotmail.co.uk I don\'t know whether or not I need the Ignition upgrade. what power is the stock ignition good up to? Also whereabouts can you purchase it? I found one in the Mazda rotary store and that\'s it. If I can get away with it I will but if I need it I need it. Also do you need to map the car again if you decide to do it at a later date after it has already been mapped?

Thanks

[kompactor]

Some iridium race plugs (greddy, ngk, HKS) will help with the stock ignition, and upgraded for that matter. The electrode is smaller and allows for a hotter spark with the same amount of voltage. They also last a very long time. Unfortunately they are expensive, ranging between $125-$200 USD per set. (worth it in the long run due to how long they last)

People have made over 500 rwhp with the stock ignition, although not ideal. The biggest issue is when running large amounts of boost, or adding water injection. Of course is also depends on the condition of the stock system too. You would most certainly pick up a bit of power and response by adding an ignition amp.

 //www.wannapeed.com has a good price on the twin power systems, they are an awesome company to work with, shipping might be high on international orders though. If you shoot them an email, they can get pretty much anything you need.

[kompactor]

EDIT: delete this post, wrong thread

[wiggman2030]

Thanks for the advice, I think I will take it as it comes lol.  I\'m getting the car mapped by someone who steve knows, he does it in the passengers seat while i\'m driving. I would prefer to get it on the dyno but I live in Norwich and it\'s a long way to go to get to anywhere decent. I will look for the plugs you mentioned if I need them.

[turbotoaster]

that was the one he will be on about, peaks at 0.9bar and holds 0.8bar

the issue he had for not turning the boost up was the w/i was blowing the spark out, so he will be upgrading to a fmic intercooler instead of trying to get away with the w/i.

since your running a fmic you should be fine, you may need to change your plugs after 360bhp but every car is different, a set of B10egvs are only £20 for a set of 4 so they are a faily cheap change.

Whats the lad whos gonna do your mapping for you?

[wiggman2030]

Thanks for the graph, sorry but what is w/i? Also I can\'t remember the guys name it\'s mark something I believe.

[turbotoaster]

w/i is water injection.

when a turbo compresses air to push into the engine it heats up, this hot air entering the engine makes it easier for the engine to knock(detonation) which blows your engine up.

W/i has to advantages, spraying water into hot air causes the water to evaporate, in doing so it takes alot of the heat out of the air, so colder air equals less chance of knock.

Also if you use enough water it will also mix with the fuel and slow the burn process down inside the combustion chamber.........the slower the burn the less chance of knock, kind of like what higher octane fuel does.

the issue you have is water is very hard to ignite in a combustion chamber which means it can weaken or even blow out your spark causing a loss of power.

this can be overcome by increasing the spark output by adding a ignition booster(like a hks twinpower) and also changing plugs to a colder set(standard plugs cant cope with the extra heat from a tuned engine)

[wiggman2030]

Oh. thanks for the little lesson in water injection lol So I guess a bigger intercooler is better or should I say less troublesome than water injection then? I had a look at those plugs you mentioned. They need gapping I believe. Would it be better to get the iridium ones as someone mentioned that they don\'t last very long.

[turbotoaster]

yeh, getting a bigger intercooler is better, but you have a fmic anyway so you will be fine.

running 1bar of boost is fine without w/i as i run it all day on a crap cooler, when i change to my front mount ill be upping the boost to 1.1bar, the only thing i think will hold me back is ignition which is being sorted promptly.

On the thoughts with spark plugs, its all depending how much you want to spend, you can pay £100 for a set of plugs that last you maybe a year or £20 that might last you 6 months, ive seen them both do massive power.

Yes the £100 are better, im not denying that, but for the extra cost i dont believe they are worth it unless your pushing the envelope or your feeling very flush.

[kompactor]

The extra cost is worth it. (And I\'m cheap)  Especially worth it if running an ignition amp. I was running egv\'s and after less then 2 months they were toast. Electrode all worn down and rounded. Ignition breakup under boost. Switched to greddy iridiums, have been running the same set for almost 2 years now, electrode hasn\'t worn at all. Maybe some setups can get by with  cheap plugs, but definitely not mine.

I bet in a setup like yours the iridiums would last near forever. Saves money in the long run.

I should also mention running 10\'s without an amp can cause the plugs to foul out. Running 7\'s or even 9\'s on a high boost setup can cause a lot of heat buildup that can lead to premature plug wear, or worse a hotspot that could preignite the mixture. Best bet is 10\'s with an amp.