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250+ hp... how doable?


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Hello, I can confidently say I'm addicted to boost. We had a quick drag event and I never wanted it to end. Currently I'm pushing 190ish to the rear wheel, but I'm a little unhappy in how hard of a wall I hit around 120-130. (Naked problems) Obviously the only answer here is more boost. 

I've seen many builds above the 250 hp mark, but my question is with a properly tuned efi and good standalone for ignition, what else should be reinforced on the motor? I see the use of busa rods with a 2mm spacer, would just the spacer allow for a low enough cr? Are busa rods really that much stronger for it to be necessary for the 250 hp mark?

I've also considered that HD valve springs might be necessary, wouldn't a lot of boost have the possibility of holding the intake valves open? 

Depending on the cost of aftermarket rods, I might get a set of those. I've heard bad things about certain brands though.

another thought of mine is finding a way to use my 13 psi more efficiently. Obviously on carbs it's tuned rich to avoid any flukes in fueling blowing the motor, so I lose some power there. I've seen the forum of gas flowed heads and GSXR cam swaps doing some good work for turbos, but are there any other secrets with charge piping, intercoolers, or plenum design that wouldn't necessarily require more boost for 250 hp? Unfortunately my manifold flange is sorta "unique" so the vf ball bearing turbos aren't an option for a better spool.

so with all this said, I ask of any recommendations to help me safely reach my target number, thank you all.

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If you are 'hitting a wall' @ 120-130 something is wrong or you are whimping out LOL! My old donkey Kawazuki, naked, w / flat bars, Suck through T2 garrett, S&S carb and 10psi = 200 and a bit hp, would hit 155 and probably a bit more if it wasn't for the parachute riding position! Engine had a 1186 kit + 2mm spacer plate due to 12:1 CR pistons, std. crank, std. rods, std. K/L head and std. cams with a Dyna2000 ignition. 

Std rods and cranks will survive 270-280 odd hp - AS LONG AS THE OIL SUPPLY IS GOOD - lose that and the big ends get toasted and will exit the block! Forget all the flash stuff until you are pushing 300+hp or 1.5 bar + boost - really not necessary. A good ported head will help pick up hp while using less boost. Plenty of peeps using carbs upto 300+ hp so EFI not necessary - it just helps tuning and keeps AFR's more accurate.

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So, the starting point is a stock Bandit 1200 engine? In that case I think the pistons are the first thing to upgrade inside the engine. As far as I know the stock pistons can't handle much boost. I think the stock rods should be ok for 250hp but if your budget isn't too limited it might be a good insurance to upgrade them too. Just in case if you end up wanting a bit more... ;)

For making power 250hp should be still quite easy even with relatively stock engine. For reference I have recently tuned a couple of Bandits and both made about 300hp at 1.3-1.4 bar boost. Although both of them had ported heads and hotter cams but I think even without those you should be able to get 250hp with about 1 bar boost.

Few things that will help to make more power at lower boost:

  • Select a turbo that will work at good efficiency range at your target power.
  • Pay attention to exhaust manifold design, especially to collector part.
  • Same with the plenum, enough volume and even flow between the cylinders.
  • If possible, use some charge cooling. It will help especially if you run more that 1 bar boost.
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9 hours ago, Gixer1460 said:

If you are 'hitting a wall' @ 120-130 something is wrong or you are whimping out LOL! My old donkey Kawazuki, naked, w / flat bars, Suck through T2 garrett, S&S carb and 10psi = 200 and a bit hp, would hit 155 and probably a bit more if it wasn't for the parachute riding position! Engine had a 1186 kit + 2mm spacer plate due to 12:1 CR pistons, std. crank, std. rods, std. K/L head and std. cams with a Dyna2000 ignition. 

Std rods and cranks will survive 270-280 odd hp - AS LONG AS THE OIL SUPPLY IS GOOD - lose that and the big ends get toasted and will exit the block! Forget all the flash stuff until you are pushing 300+hp or 1.5 bar + boost - really not necessary. A good ported head will help pick up hp while using less boost. Plenty of peeps using carbs upto 300+ hp so EFI not necessary - it just helps tuning and keeps AFR's more accurate.

She went to 150 decently. My concern was on my buddies modern liter bike the acceleration as pretty constant to 140ish. Mine shoots up to 120, but then drops off fast. my 60 - 130 time was measure at 6.3 seconds, but my 60 - 120 was around 5. It gets slower from there. 

Thats good to hear about the carbs though, more money for my ignition setup. As for the oil, other than ensuring the jets/passages are clear, what else can be done to the oil system to ensure it's "good"? 

Thanks for the good info. 

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1 hour ago, Arttu said:

So, the starting point is a stock Bandit 1200 engine? In that case I think the pistons are the first thing to upgrade inside the engine. As far as I know the stock pistons can't handle much boost. I think the stock rods should be ok for 250hp but if your budget isn't too limited it might be a good insurance to upgrade them too. Just in case if you end up wanting a bit more... ;)

For making power 250hp should be still quite easy even with relatively stock engine. For reference I have recently tuned a couple of Bandits and both made about 300hp at 1.3-1.4 bar boost. Although both of them had ported heads and hotter cams but I think even without those you should be able to get 250hp with about 1 bar boost.

Few things that will help to make more power at lower boost:

  • Select a turbo that will work at good efficiency range at your target power.
  • Pay attention to exhaust manifold design, especially to collector part.
  • Same with the plenum, enough volume and even flow between the cylinders.
  • If possible, use some charge cooling. It will help especially if you run more that 1 bar boost.

What cams did you use? mine are rusting/pitting on the lobe, and the chrome on my rockers are wearing off, so that's definitely on my list. (motor had 68k miles before turbo) I have busa pistons and APE studs and nuts. Other than that and an HD camchain, the motor is pretty much stock. I'm currently running a td05-16g, which I believe can handle about 300 hp before running out of breath. Do you use an external wastegate? 

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19 hours ago, rerb said:

What cams did you use? mine are rusting/pitting on the lobe, and the chrome on my rockers are wearing off, so that's definitely on my list. (motor had 68k miles before turbo) I have busa pistons and APE studs and nuts. Other than that and an HD camchain, the motor is pretty much stock. I'm currently running a td05-16g, which I believe can handle about 300 hp before running out of breath. Do you use an external wastegate? 

The mentioned bikes weren't built by me. I just made engine management installation and tuning for them. So I don't know all the exact details about the engines.

One of them had ported Bandit head, some "hot" WebCam cams and Holset HX35 turbo with external gate. Another one had GSX-R1100 head with oversize valves, stock GSX-R cams and TD05-20 turbo with internal gate.

Yes, a TD05-16 should be fine for 250-300hp so I would leave that alone for now. Sounds like you have the most important stuff inside the engine done too. Hotter cams might be a good idea if you have to replace them any ways. That should help to keep torque up at high rpm.  But I wouldn't go too extreme with them. For example that one with Web cams was a pain to get mapped properly at the mid rpm range and still didn't give too amazing power figures at top end. I think stock GSX-R cams could be a good compromise. Increasing the compression and tightening the squish clearance could be a good idea since the Busa pistons result very low compression and pretty bad combustion chamber shape. But then you need to be more careful with tuning...

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7 hours ago, Arttu said:

The mentioned bikes weren't built by me. I just made engine management installation and tuning for them. So I don't know all the exact details about the engines.

One of them had ported Bandit head, some "hot" WebCam cams and Holset HX35 turbo with external gate. Another one had GSX-R1100 head with oversize valves, stock GSX-R cams and TD05-20 turbo with internal gate.

Yes, a TD05-16 should be fine for 250-300hp so I would leave that alone for now. Sounds like you have the most important stuff inside the engine done too. Hotter cams might be a good idea if you have to replace them any ways. That should help to keep torque up at high rpm.  But I wouldn't go too extreme with them. For example that one with Web cams was a pain to get mapped properly at the mid rpm range and still didn't give too amazing power figures at top end. I think stock GSX-R cams could be a good compromise. Increasing the compression and tightening the squish clearance could be a good idea since the Busa pistons result very low compression and pretty bad combustion chamber shape. But then you need to be more careful with tuning...

Right, good places to start. thank you. I've seen GSXR 750 and 1100 cams used on different bandits, anyone know which is best suited for turbo/high rpms? Thanks. 

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With a turbo you don't need high rpm's! My biggie makes peak between 8500-9000! Unless a cam is specifically ground for turbo use ie. lots of lift and short duration it'll probably be worse - overall - compared to a std. cam, I'd stick to a stock 1100 cam for the output you want.

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6 hours ago, Gixer1460 said:

With a turbo you don't need high rpm's!

Well, yes and no. It's true that you can make pretty good power without high rpm. But if you want even more power without running stupidly high boost then there isn't much other choices than keeping the torque up to higher rpm.

Cam selection with turbo is somewhat complicated since the turbo choice affects on how the cams work. Traditional wisdom about short duration turbo cams is true with smaller turbos that run higher exhaust pressure than boost. But if you can keep the exhaust pressure at the same level with boost or even lower then the cams work more like on N/A engine.

But yes, for that 250hp target I wouldn't use anything hotter than stock GSX-R1100 cams.

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7 hours ago, Arttu said:

Well, yes and no. It's true that you can make pretty good power without high rpm. But if you want even more power without running stupidly high boost then there isn't much other choices than keeping the torque up to higher rpm.

Cam selection with turbo is somewhat complicated since the turbo choice affects on how the cams work. Traditional wisdom about short duration turbo cams is true with smaller turbos that run higher exhaust pressure than boost. But if you can keep the exhaust pressure at the same level with boost or even lower then the cams work more like on N/A engine.

But yes, for that 250hp target I wouldn't use anything hotter than stock GSX-R1100 cams.

Right, thank you. 

 

13 hours ago, Gixer1460 said:

With a turbo you don't need high rpm's! My biggie makes peak between 8500-9000! Unless a cam is specifically ground for turbo use ie. lots of lift and short duration it'll probably be worse - overall - compared to a std. cam, I'd stick to a stock 1100 cam for the output you want.

I wrote that a little weird, I meant more with helping out in the 9k rpms area, not taking it to 11k+. I know the b12 cams are a little different for midrange power (atleast thats what I was told) so an 1100 sounds like the right swap. 

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I would stick with what you have and invest 8n some dyno time before dicking about with cams. They need to match where your turbo is working best. You can end up killing low down torque because your cams are too extreme, and also loosing top end power because when the cams work the turbo is done.

Ideally you want some dyno time to see exactly whats going on and where you can improve before you dive in.

I run a VF23 IHI on mine and 300bhp at 9000rpm is where it stops, but it makes peak torque of 200ft lbs at 6000rpm. Thats with bandit 1200 cams, I tried gsxr 11 ines and it dropped peak torque down, and made no more power because the turbo was already at its limit.

Edited by MeanBean49
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9 hours ago, MeanBean49 said:

I would stick with what you have and invest 8n some dyno time before dicking about with cams. They need to match where your turbo is working best. You can end up killing low down torque because your cams are too extreme, and also loosing top end power because when the cams work the turbo is done.

Ideally you want some dyno time to see exactly whats going on and where you can improve before you dive in.

I run a VF23 IHI on mine and 300bhp at 9000rpm is where it stops, but it makes peak torque of 200ft lbs at 6000rpm. Thats with bandit 1200 cams, I tried gsxr 11 ines and it dropped peak torque down, and made no more power because the turbo was already at its limit.

That makes sense. I actually had mine dyno'd and peak power was at 9k, then sharply fell off. Sounds like a replacement set of stock cams is best for me. 

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12 hours ago, MeanBean49 said:

Where was your peak torque? What shape was the curve?

 

Was barely running, all those bog makes are from 8-9 afr. Put smaller mains in, huge power boost just from fixing the mixture a bit, but haven't had the chance to dyno it again. Dyno operator said he's noticed that the dyno reads about 10 hp less than you'd feel on the street because of air velocity, not sure if true or not.

20210820_172324.jpg

Edited by rerb
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9 hours ago, rerb said:

Was barely running, all those bog makes are from 8-9 afr. Put smaller mains in, huge power boost just from fixing the mixture a bit, but haven't had the chance to dyno it again. Dyno operator said he's noticed that the dyno reads about 10 hp less than you'd feel on the street because of air velocity, not sure if true or not.

20210820_172324.jpg

Yeah hes talking absolute shite lol.

Shame youve not got the AFR trace on the graph. 

Peak looks to be around 8k so fairly high up rpm range. GSXR cams probably ideal.

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12 minutes ago, MeanBean49 said:

Yeah hes talking absolute shite lol.

Shame youve not got the AFR trace on the graph. 

Peak looks to be around 8k so fairly high up rpm range. GSXR cams probably ideal.

Yeah, I had only a dump pipe at the time so nowhere for the sniffer to sit. It's on my list to get another dyno run in for sure. 

But as far as the cams though, if it will help me make more peak power without more boost, I'll gladly do it. It might not be necessary for 250, but with a ported head, I just don't want to push more than 13 psi for reliability concerns.

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10 hours ago, MeanBean49 said:

Yeah hes talking absolute shite lol.

Shame youve not got the AFR trace on the graph. 

Peak looks to be around 8k so fairly high up rpm range. GSXR cams probably ideal.

I see on DW holeshot performance they have "factory drop in cams" that sound a lot like their gsxr cams. Anyone have experience with them? 

Screenshot_20210903-105631_Chrome.jpg

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My experience with a similar setup: 

Busa pistons, 0.5mm skimmed block, Chinese cxracing td05-20g turbo (a really slow spoolup turbo actually), ported gsf1200 head, gsx1100f cams, ape studs, 36mm carbs, big volume, dual chamber plenum, Ignitech CDI mapped with map sensor, and I made 240bhp at the wheel with 0.8 boost of pressure, that I consider pretty good values considering no intercooler and the "low" boost pressure.

IMG_20210904_135520.jpg

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9 hours ago, Goo'Roo said:

My experience with a similar setup: 

Busa pistons, 0.5mm skimmed block, Chinese cxracing td05-20g turbo (a really slow spoolup turbo actually), ported gsf1200 head, gsx1100f cams, ape studs, 36mm carbs, big volume, dual chamber plenum, Ignitech CDI mapped with map sensor, and I made 240bhp at the wheel with 0.8 boost of pressure, that I consider pretty good values considering no intercooler and the "low" boost pressure.

IMG_20210904_135520.jpg

ooh that curve looks very nice. May I ask why you went with a 20g as opposed to a smaller turbo?

Looking into it, getting an ignitech CDI seems cheaper and better than a dyna2000, something I want to do this winter. How big of a pain was it to install? the dyna seems very simple without the need of a custom triggerwheel, and lets you keep kickstand switch function. Are you running stock coils too?

Edited by rerb
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10 hours ago, rerb said:

ooh that curve looks very nice. May I ask why you went with a 20g as opposed to a smaller turbo?

Looking into it, getting an ignitech CDI seems cheaper and better than a dyna2000, something I want to do this winter. How big of a pain was it to install? the dyna seems very simple without the need of a custom triggerwheel, and lets you keep kickstand switch function. Are you running stock coils too?

I used the 20g because I had it from a proboost kit. 

Ignitech is very simple, comes with the wiring adapter, but it's anyway really easy to wire and setup. 

Stock triggersystem works and you can maintain the switch off safety system and add a killer switch too. 

With a gear switch you can activate the quickshift too.

I used the green Dyna coils.

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On 9/1/2021 at 2:03 AM, Arttu said:

Well, yes and no. It's true that you can make pretty good power without high rpm. But if you want even more power without running stupidly high boost then there isn't much other choices than keeping the torque up to higher rpm.

Cam selection with turbo is somewhat complicated since the turbo choice affects on how the cams work. Traditional wisdom about short duration turbo cams is true with smaller turbos that run higher exhaust pressure than boost. But if you can keep the exhaust pressure at the same level with boost or even lower then the cams work more like on N/A engine.

But yes, for that 250hp target I wouldn't use anything hotter than stock GSX-R1100 cams.

It's getting fun when you reached the max torque... And that is at a lower rpm then NA

 

 

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