rider384

Is it possible to bore the cylinders out that much on a stock B12 block? I remember reading something about a "big block", but from what I can gather the Blandit 1200 engine is the big block. Going bigger would definitely help reach the goal. Also, unrelated to that, the B12 block is a 59mm crank, correct?

My only worry with that is whether or not the turbo pistons/high comp pistons are different in terms of design - how it spreads the load, how it handles boost (regardless of compression ratio). As I said, I know almost nothing about piston design so I'm hoping someone who's gone down the fully built engine road can chime in. Holeshot makes an 11:1 piston kit for the 1157, but that's about it as far as I can tell. It's so little work to fit Hayabusa pistons (bore the cylinder jugs 2mm over) that no one really makes bespoke Bandit pistons. I'm just struggling to find information on how to make the compression difference work.

Started ordering parts for my 1157 engine build, shooting for 400+ to the wheel. Have a set of h-beam conrods on order right now, trying to work out which Hayabusa pistons to go with but I'm confused on compression numbers. From what I understand, stock Hayabusa pistons in an 1157/stock crank/stock rod length will net around 8.5:1 compression, which is perfect for boost, but I'm looking to go beyond the capabilities of stock Hayabusa pistons. All forged pistons for the Hayabusa seem to be either high compression (13:1ish) or low compression (8.5:1ish), neither of which would land at an ideal compression for a turbo 1216. Never built an engine before, I don't understand much about metallurgy or piston design so forgive the amateurish questions: Am I even on the right track thinking that 8.5:1 Hayabusa pistons in an 1157 would net an insanely low compression ratio, due to the drop in compression ratio with stock Hayabusa 11:1 pistons? IE Stock 11:1 Hayabusa pistons in an 1157 nets ~8.5:1, therefor 8.5:1 Hayabusa pistons in an 1157 would net ~6.5:1? Or am I oversimplifying it? Between the JE, Wiseco, and Carrillo pistons, which are generally regarded as having the highest power capabilities? Alternatively, which are the best value for the money? What part of the 1157 could be shaved off to raise compression, assuming I get the 8.5:1 Hayabusa pistons? Alternatively, as I understand there's some head that bolts on to the 1157 that raises compression ratio about 1.5 points due to a smaller chamber, is this correct? I understand I'll have to mathematically work out what specifically will need to happen with my engine to get my specific build where I want it in terms of compression, I just want to make sure that I'm on the right track before ordering pistons, lest I end up with something completely unusable. Thanks

I ordered them straight from their website, maxpeedingrods.com There was also a couple sets available on Eblag (USA) a couple days ago, but they were about $30 more than what I paid on their website. If you order from the website the coupon code "SUB13" saved me $20.

Thanks for the advice guys! I think say what now!? hit the nail on the head, I was confused because of the different bearing size offerings from Suzuki. Clive, I went with APR2000 bolts. I know those were popular in the Miata community, are they acceptable at higher RPM and load? I ended up ordering the Maxpeedingrods after reading a couple good reviews and seeing people make some big power with them.

Hi all, getting tired of ~220ish whp on a stock engine and would like to build my engine for 400+. Not to be useable, but because I want to. As far as I understand, I'll be well past the limits of the stock rods so upgrades are in order. What I'm primarily wondering about are the differences between all the 1157 engines that came in Bandits - the brand I'm looking at is Maxspeedingrods, because they're cheap, but they list them as being for '96-'98 Bandit 1200s and '93-'98 GSX-R1100s. I know someone I trust who is running them on a 2000 model year, but I just want to confirm that, at least in theory, they'll work. Here's the specs straight from the manufacturer: "Dimensions: Center to center length: 117mm; Big end diameter: 41mm; Small end diameter: 20.02mm ( tapered small end); Big end width: 21mm; Small end width: 21mm" I am worried about the big end diameter - from what I've found online, there are 3 different sizes that came in 1157 engines, but I can't find what those sizes are. Can anyone confirm and tell me which diameters came in which engines/years?/ I would like to avoid Hayabusa rods as that's a much more expensive (albeit proven) route. I have fixed, turbo'd, and fuel injected this bike for less than $2,500usd including the cost of the bike - it's an experiment in cheapness, I'm not looking to debate the efficacy of cheap parts or the risks associated with them. Thanks

Sourced some Fuel Injector Clinic 625cc injectors for an SRT-4 that slipped right in with some different o-rings and a small spacer in the fuel rail mount. Easy sub 1 hour installation, even with swapping the injector pigtails out. I also took the opportunity to lower the base fuel pressure from 3.5bar to 3bar, since I now have more than enough injector to run up to the limits of the stock engine. Bike idles beautifully on all 4 cylinders, albeit very rich, even with the change in injector size accounted for in the fuel constant. Hopefully I'm just down to tuning at this point.

Ok, took it for a quick ride, going to compile some information here: Charging system was bad, has been fixed When the Microsquirt is set on semi-sequential mode, only cylinders 2 and 4 fire. Doesn't matter if it's 1 squirt/simultaneous or 2/alternating, only cylinders 2 and 4 fire. After running on semi-sequential mode and turning the bike off for a couple seconds, it will actually run on all 4 with the fuel pump turned off, presumably from all the fuel vapor hanging around in the intake. The bike fires on all cylinders when set to untimed batch injection, but it starts on two cylinders, runs on 4 after a couple seconds of idling, then goes back to running on 2 when the RPMs go up or load is placed on the bike. Presumably running 2 and 4 normally, and 1 and 3 running off fumes in the intake from ill-timed injection. All 4 spark plugs are firing, 1 and 4 together, and 2 and 3 together I speculate that something is off with the fuel injection timing/my wiring. I currently have cylinders 1-4 and 2-3 wired together for both fuel and spark, which I now speculate to be causing the fuel injection timing to be off by 180* on two of the cylinders. Should I have cylinders 1-3 and 2-4 wired together for the fuel injectors, and 1-4 and 2-3 for the spark? Do I have something backwards? Edit: From what I've found online it really doesn't matter if injection timing is 180* off, so that idea is out the window. I'm going to swap the fuel injectors around and see if the running cylinders follow them. Edit2: Running cylinders followed the injectors! Guessing I didn't clean the fuel rail well enough after I extended it and it clogged 2 of the injectors. Going to order a set tonight with express shipping, can't wait to get them in and get a good run out of this thing.

I think the way I'm wired is messing with the MS voltage readings; log readings are consistently lower than a multimeter on the battery. I'm feeding the MS and pump out of the same fusebox, I'm going to take the fuel pump off and put it on it's own separate circuit and see what happens. Reason I bring this up is because my voltage readings with a multimeter are fine, but voltage while actually running and functioning I report from the datalogs. Regardless, battery is charging up right now, I'll report back with what I find when it's fully charged and running. Independent of this and on to tune stuff: With 1 squirt per cycle and semi-sequential fueling, I'm only running on cylinders 2 and 4. Odd, as the bike fires 1-4 and 2-3 (unless I'm mistaken). I have cylinders 1-4 and 2-3 wired together for both fuel and spark, at least in theory. Wondering if I mixed up two of the spark plug leads when I did the LS coil conversion or fucked up some of the fuel injector wiring. Regardless, I feel like I'm making progress for the first time since I posted this thread. Edit: Am I an idiot? Should I have 1-3 and 2-4 wired together for the injectors? I think I'm 180 out on the fuel injection timing on the cylinders that aren't firing.

Good news today folks: Fixed the second alternator! Popped the back open and one of the solder joints was loose. Re-soldered it and I'm putting out 13.5v at around 3,000RPM. Clamp ammeter showed that the alternator is putting out 11 amps at idle, and 25amps at just off idle. Power consumption is around 13 amps at idle, 14 at just off-idle. All is now well in my charging system, and I'll have a spare alternator lying around when the new one arrives. However, the thing still can't get out of its own way, but at least it's not dropping cylinders anymore. My focus is now moving to the tune. Per an example of an oil-cooled MS tune I got from Arttu, changed from 2 squirts/cycle untimed to 1 squirt/cycle semi-sequential. It runs, but I had to increase the idle screw and change my idle VE from 22 to 60 to get a reasonable AFR. Gonna keep playing with the tune and report back. Thanks for all the charging system advice everyone, one piece of the puzzle is now solved.

Based on the wiring diagrams I've looked at, Gixer1460 is correct. I've checked the wiring a couple times over, there's zero resistance between the alternator leads and the battery, and visibly it all looks fine. I've got a clamp type ammeter arriving later today thanks to Arttu's advice, going to check out my exact draws and alternator outputs when running, see if I've got a short causing massive draw on the system when running or something of the sort.

Updates: Tossed a lithium battery in. Made zero difference. Datalog showed 12.3v with all accessories on but bike off, 12.5-12.6v running, 13v @ 4,500rpm, 12.4v running at the end of the run. I measured 13.2v at the battery with all accessories and the bike fully off at the end of the run. Ordered a third alternator last night. Tested the alternator hooked directly up to the battery, no change. Checked all alternator wiring, it's fine. Can anyone tell me what I should expect it to read with EFI accessories at idle, off idle, and 5,000rpm? Workshop manual says 13.5v, but I don't know if I should realistically expect that with all the EFI stuff on it as well.

The alternator is run through stock wiring. I tested the resistance of the alternator connector to battery and it was negligible. I agree that it doesn't seem to be delivering charging voltage. I know it's doing something because voltage goes up when I rev it, but not nearly as much as I've been lead to believe it should. I'm seeing 13v max at high RPM, and that's with a freshly charged battery. Anything less than a fully charged battery and it'll only go 0.2-0.3v above the voltage with accessories on. I'll try wiring the alternator directly to the battery and see what happens. Maybe there's a power leech somewhere in the circuit that doesn't affect resistance.

Fully charged the battery with my charger and re-tested everything today. Full charge - 13.0v Accessories on - 12.0v Bike idling - 12.5v After a very short ride Battery - 12.5v Accessories on - 11.8v Idling - 12.2v Took some datalogs as well. I can see that the alternator is doing something, but not very much. It always seems to be trailing behind the battery voltage. IE on a fully charged battery, it will put out 13v, but the system voltage doesn't stay there for long, just keeps getting less and less. Final datalog tonight showed the system voltage dipping down into the 11.9v range while running. I think the battery is shot and possibly the alternator I just put in as well. I'm going to throw a lithium battery at it and see what happens. If that doesn't work, it's another new alternator. If that still doesn't work, I'm going to light the bike on fire in my driveway. Built this thing 6 months ago and I haven't gotten a solid pull out of it yet, getting towards the end of my patience with it.

Thanks for the responses guys. I'm going to check the amp draw at idle and see if my accessories are pulling too much power. If so, I'll lower my base fuel pressure and see what else I can trim off. I think I'll remove the stock battery and hook up a known good car battery to it and check the voltage when running. I think Gixer1460 said is spot on - feeding a bad battery voltage is like feeding a prisoner after they've had a lethal injection. Wondering if the battery is bad enough that it can't take a real charge - even when I hook it up to my charger and give it full charge, it drops down to 12.5v after being disconnected for about a minute. At least I can potentially knock the battery off my list of suspects that way.

Updates: Put a new (used) alternator in. Battery reading 12.5v with everything off, 11.9 with all accessories on, and 12.4 with the bike running at idle to low RPM. Can anyone confirm if that seems right? It seems low to me. Wondering if the alternator is better than the old one but still junk. I've tested the alternator wiring, there's negligible resistance between the alternator and the battery. Bike ran ok earlier today; I got higher in the rev range and more throttle before it dropped cylinders. Shut it down for a couple hours, accidentally left one of the gauges on so the battery drained a bit, checked it and it was still at 12.5v, but it ran as poorly as it did before, maybe even worse. Quick summary of what I've tested tonight: Battery voltage off/accessories on/running: 12.5v, 11.9v, 12.4v, respectively Voltage drop between coils and battery. No drop at all Checked for fuel line restrictions and fuel pressure - proper set pressure (50psi) and no kinks in line All cylinders firing, though cylinder 3 takes a while to fire after startup (5ish seconds of dead time until it starts firing) Plan going forward, in order, each subsequent one being done only if the previous one doesn't work: Alternator charging circuit output mod New battery New alternator again Burn the bike to the ground Anyone have any thoughts? I have a suspicion that the battery can't handle the power output of running all the accessories that I've added, and/or the second alternator I just put in is junk, or that something is wrong with the charging circuit itself, but if I do all of those and it's still not running right I really have no idea where to look.

Good idea with the spare cover, thank you. Already found TDC and marked it with an m14x1.25 bolt, that's how I found I was so far off. Once I have the alternator replaced I'll double check timing at higher RPM. If by fit a wheel to the crank you mean a trigger wheel, I'm already running a 24-2. Battery voltage actually dropped significantly when it was running. Definitely the alternator.

Not sure if I tested this correctly, but the alternator with no load was putting out 0.2v at idle and around 3v at higher RPM. Assuming the alternator doesn't need a load on it to be tested correctly, it's definitely the problem.

Ha, at this point, everything except the gauges and lights are running on my own harness. I've had this thought myself, but it'd be near impossible to test as it only starts running poorly when I demand load from it.

Updates: Swapped to LS coils wired directly to the battery through a relay with NGK DCPR8E resistor plugs, it actually exacerbated the issue. Dwell times and other settings were adjusted accordingly, yet it still runs worse. Battery was charged and after a short ride measured at 12.4v. With ignition, accessories, and fuel pump on, it measured 11.7-11.8v (with a low-power LED headlight). Measured the voltage at battery when it was running at idle and it was 12.0v. Voltage drops down to about 9.5v when cranking. Just checked some recent datalogs and the system is sitting at 11.8-12.2v when it's up at 4,000-5,000rpm. Datalogs also show that the system voltage actually goes up after the bike is turned off. I think forced2 and Gixer1460 might be bang on the money in their above replies. 11.8v at 5,000rpm seems extremely low, and voltage drop of 0.7v while running accessories seems fairly extreme, as does 11.7-11.8v at 5,000rpm, as shown in one of the logs. Beginning to think it's both the battery and alternator on their way out. It would also explain why the bike initially runs well and only starts running like shit when I try to get on it; the alternator can't keep up, and the weak battery runs out of power for everything. When I turn it off and let it sit for a minute, it fires up and runs fine again until I get on it, when it falls on it's face again. Going to get the battery load tested tomorrow. If it checks out, going to start going through the charging system. If it doesn't, going to replace the battery and see what happens. But based on all the symptoms, the fact that it got worse with the 4 ls1 coils, and the fact that the system voltage goes up when the bike is off, I believe it's some aspect of the charging system combined with a bad battery.

Ha, it was never meant to be a pretty bike . But yes, once it's functional I'm hoping to tuck the wastegate a bit further in towards the bike (and loop it into the exhaust so it's not a screamer pipe) and re-do/clean up the charge piping, I think it'll help a lot with the aesthetics. But I'm a firm believer in function over form, at the end of the day it doesn't have to be pretty if it shows people my tail lights. Funny enough, the whole reason the turbo is there is because of oil drainage; the original kit I built had the turbo down low, but I could never quite get the clearance I wanted and had constant oil draining issues. I'll take an ugly bike over one that won't stop blowing smoke.

It was all parking lot work before I moved, looking forward to being able to hook up my battery tender while working on it now that I have a garage. I ordered LS1 coils last night, I'm going to run a relay off the stock wiring to power them directly from the battery. What is this alternator mod you're referring to?

I'll get a multimeter on the alternator when I get a chance. It would make sense as my battery has needed a lot of charging, but I always assumed that's because I have to have the ignition on a lot for diagnosis, probably more time with the ignition on than the bike running.

Good, albeit slightly embarrassing news to report: Poked around today, found one of the coils was installed with reversed polarity, and found two of the fuel injector plugs swapped. Reversed both, and the bike idles, revs, and does low-end like an absolute dream. AFR is spot on, it's smooth, and up to a certain point, power delivery is almost factory. I also tested the spark output with the MS test mode and it does spark on all cylinders, even at high RPM (in the test mode, anyways). However, the primary issue still persists. With the now smooth-running bottom end, it has become very clear that the bike is dropping cylinders when I demand a real load from it. Seems to get worse as the bike gets hotter, but that could just be my imagination. Tested the voltage drop at the coils and it was fairly significant; battery was putting out 12.4 volts, and the voltage at the coils was around 11 with a bit of fluctuation. That wasn't even under load, just static voltage at the coils, engine off. As such, I'm guessing that my coil pack wiring has seen better days, and is likely the culprit. Since I'm going to be re-wiring anyways, I think I'm going to bite the bullet and just order some LS1 coils. Any thoughts? Does static voltage not matter, only load voltage? I have a feeling I'm tantalizingly close to fixing the issue. Also, Arttu, I have not tested the timing at higher RPMs. My downpipe is poorly designed and sits right in front of the timing cover - I would have to run completely open dump off the turbo at 5,000rpm to test. I just moved into a new house last week, don't want to piss off the neighbors quite yet.

Ah, my mistake, how could I forget . It's not much to look at, it's a $600 dollar turbo kit and my first ever attempt to fabricate anything.