Hey Everyone,
With a lot of guys and girls nearing the end of warranties, the need for more is catching up with them. Simply put, boost is the best bang for the buck. However, it is not a project to take lightly. Many things can go wrong, and the outcome is not always pretty... but when the kit is installed, and running properly, nothing else matters!
The below information is more geared towards the Hiboost kit. I will add to this while I think of things. I want to try and keep it MZ3 specific, and not just another Boost FAQ... there is enough out there!
Here are some things to think about if you want to boost:
Gauges
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Cheap vs Expensive
While I am a fan of nice fancy DEFI gauges, I do not see the need for them while running low boost. This is personal preference though. Are they better than cheap gauges? YUP! Will they give you a more accurate reading? It depends... If I am running 8PSI, and they both read 8PSI at the same time... great! However if building a car with VERY strict tolerances, DEFI may be for you (or if you have the money, and want the gauges). I would also assume that the more expensive gauges will last longer, and have a lower failure rate also. But for my project, I went with cheap, and so far, so good!
Which ones??
Again, this is personal preference. In my opinion a BOOST gauge and AFR gauge are essentials. A boost gauge will show you how much boost you are running at any given time. An Air/Fuel Ratio gauge will give you your ratings in AFR or Lambda (depending on gauge... AFR is most common now). When buying an AFR gauge, a wideband is more desirable in a forced induction setup. It has a widesweeping 02 sensor, as opposed to a narrow sweep. This provides greater accuracey, and gets rid of the oscillation seen on narrowbands, which is the only way to tune properly. If going for a cheap gauge setup, be prepared. Even used Wideband often fetch $200+. AEM and Innovate Motorsports make 2 of the most affordable units, they are also ranked highly. Both use Bosch sensors too. If you have a third gauge hole (like me) and need to fill it... you cantt go wrong with a Oil Pressure or Pyrometer (aka EGT) gauge either.
Gauge Pods
At the time of writing this, there are a few options available. Lotek makes a piece that goes above the center vents. It is an add-on, and not a replacement panel. Most people buy this, and mold it to the existing piece, to form an OEM look. A-Piller pods are also readily available most places. If neither of these appeal you can install them wherever you like, but it is a custom job.
Sandwich Adapters
When boosting an NA Mazda3 with a HiBoost kit, you use the stock Oil Pressure location to feed the turbo. This is a problem if you want an oil pressure gauge. Having more and more brass fittings causes weight, and vibration. Brass fittings dont like vibration, so I opted to use a sandwhich adapter. This goes between the oil filter and housing, and has fittings in it. To do this on a 2.3L you must convert to a spin on housing (from a 2.0L) and use the 3/4"-16 sandwich plate (Honda Size!)
Additional Supplies
When installing gauges, there is not much you need. A couple rolls of electrical wire (I prefer diff colours, as opposed to labeling), connectors, and tape should do. Boost gauges will come with tubing and vacuum line "T".... I found I needed more tubing though.
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Turbo/Motor Questions
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Do I have too many KMs to boost?
There is no limit to how much mileageis on a car to boost it. I have owned cars in the past as high as 200K KM when I boosted them, and had no issues. The key is to ensure that your car is in excellent running condition, doesnt burn oil etc etc. Adding power, adds stress to your car, so be prepared.
How much can I boost on a stock motor?
There is no exact number for this. Everyone may have a different experience. However, the common rule of thumb is that 10PSI can be run on a daily driver with no issues (assuming a good tune of course!). 8PSI is a much safer load, and what I currently run.
My turbo will support over 20PSI,, can't I run that?
Sure. If your internals are stock, they wont last long. Stick with the above recomendations. If you want bigger boost, you need to look into forged internals, possibly bigger injectors, clutch, tuning, etc etc. Each setup will be different for this.
Do I need a oil Restrictor?
Oil restrictors are a great idea in most setups. Hiboost has taken care of this in their kit through the oil feed line's banjo bolt.
Transmisson Questions
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What clutch do I need to buy?
Many believe that the stock clutch is great for handling 300WHP and less every day. However, clutches do where out, and often a performance clutch is not much more than an OEM jobbie. SPEC makes a full line of clutches for the car, and can suit about any build. Another low cost, and highly effective replacement is what I call the "ACT Hybrid". This is an ACT 6-Puck clutch disc, coupled with a stock Mazda Pressure Plate, and Throw out Bearing. Feel is almost the same as stock, but the clamping power to support higher HP.
How long will my stock clutch last?
No one can answer this. Driving style, abuse, manufacturing etc all play a role in longevity. Its impossible to know even on a stock car. I have approx 120K KMs on my car (as of Dec 1, 2007) and have no issues. 13K KMs of that total have been boosted.
Will my ATX transmission hold up?
The ATX tranmission is weak. Plain and simple. MTX is more desirable, but if this is not an option you will want to look into Valvebodies and possibly a built transmission. A tranny cooler is also recommended to help keep tempurates low, which in turn may lower your failure rate. The Hiboost kits are available with a different base tune that ups the boost with RPMs. This reduces the shock on the transmission at lower RPMs.
What are Billet Gears?
Billet Gears are just that... tranny gears that are made from billet steel. When running upwards of 300WHP in your Mazda3 many have found that the #3 and #4 gears have failed, as they arent designed for this power. Billet Gears offer a replacement for weak stock units, and they can handle substantially more power.
Fluids Questions
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Transmission Fluid Considerations
When boosting, it is ideal to have a good transmisison fluid. While there is some debate on wich is better, there is nothing wrong with a properly rated, high quality synthetic transmission fluid. Motul, ELF, Redline, Royal Purple etc.
Royal Purple Lightweight Shockproof
This transmission fluid has been recommended by many. It is a superior oil to other synthetics. It deals with the shock much better, but is not recommended to use in synchro transmissions (like ours). Many are running this in their Mazda3, and Protege's with no issues. It is commin to see this in modified Subarus etc, and no problems either. After using this personally in -20c weather, I must say I am impressed. The fluid does not feel much thicker than stock weight, and does not make shifting any harder.
What motor oil is recommended?
Again, a preference, but a heaveir oil is VERY recommended. Jaun himself recommends something along the lines of a 10W-50 in regular weather and even down to a 5W-40 in the winter. Also make sure to use a synthetic oil!! Synthetic oil does not breakdown near as quickly as dino oils when exposed to extreme heat, and anyone who has had a turbo, knows about that heat!
Diveability
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How is fuel Mileage affected?
Simply put... Stay out of boost if you want fule mileage! . I personally drive a 50/50 mix of city/hwy driving, and get 400-425 consitantly. This is with some spirited driving etc too. On a recent trip to South Carolina, I was doing all highway driving, and almost no boosting, and would receive 550KMs before the low fuel light came on.
When do you reach full boost?
This is a tough question, as the IHI VF22 included in my kit spools VERY quickly. Being a small, ball bearing turbo makes this happen. When cruising in 4th or 5th gear, out of boost, I can reach full boost in a matter of a couple seconds.
Winter Driving
Although most wont winter drive their boosted Mazda3s, I must this year. So far, it is just like any other Mazda3. However, you must be careful not to boost in lower gears. The torque in lower gears will cause the tires too spin, and in the winter, thats no good!
Costs
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How much is the Hiboost Kit?
The HiBoost kit retails for $3950 on their website: www.hiboost.com and costs approc $250-300 for shipping.
What else do I need to buy, and how much?
There is no exact list as every install is different. Here is a quick list of my costs:
- Royal Purple 15W40 Synthetic Oil Change w/ K&N Filter ($45ish)
- Redline Lightweight Shockproof Tranny Fluid ($45ish)
- Boost Gauge, Oil Pressure Gauge, sandwich plate, and 3 gauge pod (generic cheapie) ($120ish shipped)
- AEM Wideband 02 used ($200 cash)
- Misc connectors, zipties etc etc etc ($50ish?)
I hope this helps anyone interested in boosting. Please let me know if you have any other questions, and I will do my best to answer!