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if you raced a widebody civic that really doesnt mean much, mainly cause the guy weight his car down & probally put all the money into the body

yea but we dont know that he had everything all done up

i dont' understand how you guys doing all motor aren't doing decent at least... i mean it is basically the same engine as the miata only with a distributor instead of coil packs and very minor other differences...

you can take miata pistons (stock or forged aftermaket) and put them in the engine.. there are tons of choices for cams and cam gears.. just take miata ones and put the intake in the exhaust side and vice versa... there are at least two or three header options... and instead of a straight through exhaust create a bottleneck that opens back into straight exhaust .. its an old muscle car trick... also like the others posted port & polish, 3 or 5 angle valve jobs, pot match manifolds, shave head, bigger throttle bodie, custom or modified intake mani, i think corksport has a ecu upgrade..... i'm sure there is more that can be done.... yeah you won't have a 300 whp monster but with the 1.6 dohc i'm sure you can at least get up to 150 whp but since its all motor there is no spool up wait or anything like that... also not sure if nitrous is an option for a little extra kick after everythign else is done

honestly, if i were to start over and going N/A i would do a bp swap. with
carillo A beam rods
stock 99' miata 10:1 pistons
a shaved 99' miata head ported
with the cams im going to run in my Turbo BP
with aluminum fly and pullies
maybe custom ITB (independant throttel bodies) intake and headers
a Greddy Emanage
and that baby should be flying, should get into the low 14's maybe mid 13's. then you do a trans rebuild with the MS LSD, and throw some wrinckle walls on there and you could maybe 12's, in an empty car

i want to do an N/A build so bad. but i think i would do it on a miata cause their lighter. you could do a pretty cheep build with like 130 to 150 to the wheels pretty ealsy for around 3K. you just have to look for good deals

projectmx wrote:i dont' understand how you guys doing all motor aren't doing decent at least... i mean it is basically the same engine as the miata only with a distributor instead of coil packs and very minor other differences...

you can take miata pistons (stock or forged aftermaket) and put them in the engine.. there are tons of choices for cams and cam gears.. just take miata ones and put the intake in the exhaust side and vice versa... there are at least two or three header options... and instead of a straight through exhaust create a bottleneck that opens back into straight exhaust .. its an old muscle car trick... also like the others posted port & polish, 3 or 5 angle valve jobs, pot match manifolds, shave head, bigger throttle bodie, custom or modified intake mani, i think corksport has a ecu upgrade..... i'm sure there is more that can be done.... yeah you won't have a 300 whp monster but with the 1.6 dohc i'm sure you can at least get up to 150 whp but since its all motor there is no spool up wait or anything like that... also not sure if nitrous is an option for a little extra kick after everythign else is done

Thank you Mxproject. For the life of me I couldent understand why no one is getting more then 90+ hp off of the B6. Ive been researching the B6 motor for about 700+ hours now. And I'am positive this motor has the potential to be able to hit my horsepower goal. There is two Festy guys who are getting 150hp using carbed ITB's on the B6 SHOC 8v.

I'am dertemined to use this motor for my S1600 GpF/G2 Rally car. So as far as running a turbo that is out of the picture, no "If's" and "but's" about it. This car is strictly a rally car and the motor will be torn down between events.

-Bill

DJGypsy wrote:NA DOHC B6? forget it. here are the engine mods i have:

completely re-built motor
ported & polished head w/ 3 angle valve job
2 1/4" straight pipe exhaust w/ 2 resonators
CAI
ACT clutch

i do all the regular maintinance (oil changes, etc)

i've spent over $2500 on that stupid engine, not including other areas i've spent money on, and all i get for a 1/4 mile:

18.7 @ 73mph

car was empty of everything except for 1/4 tank of gas (still have full interior, though)


i get so brokenhearted. i work on her and spend money on her, and i'm still slow

so, go turbo...i will be boosting within 2 years when i have a solid financial base after my summer graduation from UCF.

EDIT: i will be BP-T swapping...

You're very slow I have a 94 DOCH I did on stock- 17.5 @ 75mph

Then I did - 16.3 @ 83mph with:

- Without the muffler
- Did a catlitic conversion with the stock one
- Disconnected the hose A from the pressure regulator
- Join the two coolant hoses from the throttle
- CAI
- Closed the hose that take the fuel back to the tank
- 5k Potentiometer to the coolant sensor

I think i need to point this thread in the right direction


HOW MUCH WHP WILL YOU GET WILL AN ALL MOTOR BUILD

Times slip really dont tell you that much because, not all tracks are the same etc etc...

I think jarid who had his whole engine built, protege tranny etc etc
thinks he is @ 135 whp...but he got a turbo on so its only an estimate

You are right about the time slips. In drag racing HP is only half the equations. There is an old drag racers saying build the engine for torque and let the Hp take care of itself. It is the guy with the most useable torque that is faster on the 1/4mile or light to light. Most Mazda 4 cyl. engines are inherently torquer. The 2 real exceptions are the FE and the B5 engines which have good torque curves and make more HP/litre than there cousins. By just increasing engine size, say with a longer stroke crank, torque will increase at lower rpm but not necessarily increase peak horsepower by much at all. The easiest way to increase HP is to move the point where peak torque is made to a higher rpm. If an engine that makes 100ft/lb torque @4000rpm and 105hp @ 5500rpm and you were to move the peak torque up by 1000rpm the HP becomes 124hp. The 2 most common ways to do this is to retard the cam timing and to increase the primary exhaust manifold runner diameter. To make a real increase peak HP you need to increase peak torque by selecting the engines most efficient peak torque rpm not just sliding the torque curve up or down the power band. To increase torque you need to either process more air/fuel mixture per cycle or extract more energy from that air/fuel that is burned. The ultimate horsepower potential of any engine is really a function of the flow capacity of the induction system but at the same time just making things bigger isn't the answer either. Looking over some of the mods that have been mentioned I see different mods reduce the effectiveness of one another or just cancel out each other. I did a rough calculation the other day where I see guys installing modified FS 2L header on the B6. This is basically only a cosmetic modification as the primary pipe cross section is already too large for even the 2L making about 200hp. A B6 DOHC make around 200hp only needs a pipe with an inside diameter of 0.875-1.0". to make. This calculation seems to be about right if you have ever looked at a Toyota 4AG-E which is making 100hp/L the OE Exhaust header looks like drinking straws and are long which pulled the torque numbers back up in the lower rpm's. The increase in tube diameter of the 2L headers on the B6 is pulling the torque curve into rpm's higher that were even a modified engine can support making peak power. Basically all you are doing is reducing your low rpm torque making your car slower accelerating and clipping the power curve before the engine can make peak HP. I can also see issue when people say they ported and polished their heads and intake manifolds. I see many shops just hog out the ports to as big as possible and the all ports match in size unless the owner specifies exactly what they want done or just do what they would do to a Honda which is already a deep breathing engine than the B6 and even the BP. I see a lot of common performance mods that each on there own have the potential to make power. Do they work together on the B6 to make more power? Not necessarily? On the DOHC you are also fighting against an EFI system that was primarily designed for emissions and fuel economy which conflicts with most performance mods and way and you don't have the high valve lift of other more performance orientated engines

im not even sure what kinda hp my 95 rs is putting out but it sure isnt anything lol. everytime i start out it just dips and bogs down not sure why but i think ima need a transmission rebuild and a engine rebuild and that is with a crappy clutch and a stock exhaust. cant do any mods since i live in cali so im stuck with this stock car haha.

Yoda - I was thinking of short stroking the B6 with the B5 crank which is 5.2mm shorter, and then going with a longer rod to get my compression back up and it also has its benifits. Im looking for my torque to be in the upper rpm range (6500). Also I know im going to have to go with a stand alone ECU which will handle a higher rev limiter. Also where would I be able to find a B5 crank I see that the Kia Sportage had the B5 but im unsure of that around here. The Mazda Z engine comes in a 1.5L with a 78.4mm stroke, but again im unsure of the fitment of that crank in the B-Series block. I have yet to find the specs on them. And how far can you bore out the B6 block?

The Sportage has the MAzda 2.0L FE-DE. The Z5 and ZM are out there are a completely different engine but there is a bolt-on turbo kit available for these engine now. I believe that you only over bore the B5/B6 block by .030" The closest crank to the B5 you will find in North America is the B3 or B6 crank which is where up are starting from. You best bet is to have a JDM importer find you a '97-'98 B5-ZE which already makes almost the same power and torque as the BP-DE

osargeant wrote:Yoda, those are some damn good numbers for a B6 SOHC engine, I am fairly impressed. I have heard that surprisingly it is easier to extract more power from the 8valve SOHC B6 engine than the 16 valve SOHC, what are your thoughts on this?

Those numbers are also higher than any all motor NA MX3 DOHC 1.6 that I have seen, especially the torque figures.

I've been meaning to answer this one for awhile and was reminded of it the other day when I hit a pothole and broke off the exhaust just behind the cat and had a serious loss of power and MPG.

My secret has been to go smaller and do everything that people say doesn't make power. I have a dyno chart from a year ago where I was at 88.4hp and 102.8ft.lbs with a stock clutch with 280000km. Almost all every modification made was generally due to a stock part failing and spending the few extra dollars to upgrade. On the exhaust side the stock (8V) manifold is hard to beat the runner are about 32mm I.D. equal length and the cast iron holds the heat in. One of the biggest roadblocks in the whole engine is the flex pipe. I replaced it with a 2" O.D mandrel bent pipe and spiral wound flex joint. This in itself makes a big difference about the same or better than the numbers for the Genie 8V headers. The most unusual feature of the exhaust is a section of pipe that goes from 2" down to 1.5" back to 2" in a very short length of pipe between the cat and flexpipe that replaced the original version that necked down to 1.75" this pulled the power numbers back up in the lower rpms and made good gains on the top end as well. The exhaust runs out to a hand made chambered resonator and finally a Flowmaster muffler. The power gains initially weren't that great until it was discovered that this exhaust set-up cause the engine to run leaner than when just a 2" diameter pipe straight out under the car or with a straight through glasspack performance muffler. Once a high volume F/P and a variable ratio FMU was installed this fixed this problem and pulled up the power numbers. On the intake side I am using a 2.25" intake pipe and the Stock VAF that an old BMW guy tweaked for me. In my sheetmetal shop I made a round to square velocity stack filter adaptor. Instead of the typical cone filter I calculated the optimum length vs. diameter was a 2" long by 7" dia cone filter air is ducted to the filter from above and in front of the left wheel. Modifications were made to the intake manifold as well with "porter" epoxy rather than a grinder when possible. Right now I got a little problem with #3 were it runs leaner that the rest and will need to be opened up a little again. There has not been a lot done to the ignition just a set of BERU S7 plugs a MSD coil and a hand made low resistance wires. So called "performance" wire sets still have about 500ohm/ft resistance but I made a set using 50ohm/ft ignition wire with MSD boots. I've also installed a 450VDC 57000mf Cap borrowed from a printing press to even out the spiked in demand. I recently had to replace the head gasket and picked up a rebuilt head cheap. Before installing the head I popped out all the valves and cleaned up the ports a little and had a friends shop re-cut the valve seat with a non standard 3 angle job. The way they cut the seats there is 17% more flow when the valve comes off the seat and better at max lift than a std. 30/45/60 valve job. The head was shave about .030" when it was remanufactured and the copper gasket when fully crushed raised the compression to about 10.1:1. The one thing that made the big difference here is have a out of production Mazda adjustable cam pulley I had to retard the cam timing a few degrees and play with the FMU to achieve max power.

I've tried some of these thing on the 16V SOHC with varying results including totaly loss of comression on the #1 cylinder on a couple engines but don't really know why the they work better in the older 8V. The torque figures are not that surprising compared to a 16V engine. The Mazda 8V engines always tend to have the torque curve of a diesel. The biggest holdup with the DOHC is the ECU programming even with a piggyback system at high RPMs the stock ECU goes whacky and starts to pullback the fuel and retards the timing.