13100 rpm fourbanger restricted to 9300 redline

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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by LoganD »

90 hp @ 9300 RPM is just under 51 lb-ft.

https://www.gixxer.com/threads/stock-k7 ... 72&slide=0

That's a K7 GSXR600 ('06'-07ish), and @ 9300 it's making what....less than 40 lb-ft? Sure, there's some drivetrain loss there but bikes are pretty efficient. I don't see you gaining 25% torque at that RPM point by playing with stock variations of heads and cams. The new latest and greatest GSXR600 is rated at ~45 lb-ft peak, and that's way above 9300.

This back of the napkin math shows you won't be racing against anyone with 90 hp that isn't heavily, HEAVILY cheating. Your competition will have a heck of a time making 80 hp if they're following the rules.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by nitro2 »

ptuomov wrote: Mon Mar 22, 2021 9:24 am The exhaust is modified stock exhaust. With extra time and money, a full custom exhaust could be made from scratch. The chassis is different from a motorcycle chassis so there’s some obvious improvements one could make, beyond just lengths and diameters.
I'd toss that exhaust in the garbage, the OEM design (modified or not) is mediocre at any rpm. A 4-1 style is easy to build and will cover the rev range you need, it may not be the ultimate but will be good enough.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by johnef »

ptuomov wrote: Wed Mar 24, 2021 1:25 pm
englertracing wrote: Wed Mar 24, 2021 12:40 pm Can you pick and choose what year parts?
For example
Allegedly Smallest ports and valves from newest
Smallest cams from oldest.
Can’t, since the service manual doesn’t instruct interchangeability.

However if you can get the head to rust and corrode, you can skim it no problem. And cam sprocket bolt holes that weren’t torqued properly can easily wear to oval shape. Etc.
If I am not mistaken the 600cc Zuks are press fit. Supersport days they use to re-press the cams sprockets. I've done it on 1000 zuks, but its a PAIN to dial it in.

Most bikes are 105 105, but Suzuki are always off because of the very reason of being press fit.

I scribe the cam-core and cam-sprocket, where they interface. Mark spot 1, then move it 5° and 10°. You can use a sharpy and wipe off after.Voila you can now advance/retard the sprocket.

Only suzuki are press fit(Hayabusa, 1000, 750cc from what I have done), all others are bolt-on, and S1000RR are adjustable from the factory, I guess they had to justify the 25k sticker price.

P.S. Suzuki are the most interchangeable bikes on the planet.
It would not surprise me if an early 2001 600 would fit your 2008, and since the older ones spun up to less RPM, it might be ideal.

I've built a 2001 gsxr1000 block with 2004 transmission, and 2016 cylinder head. And it all works.

Check APE Race parts in the Tech section, they have all the engine specs for each model, of each year.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

Great info johnef, thanks.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

LoganD wrote: Wed Mar 24, 2021 2:24 pm 90 hp @ 9300 RPM is just under 51 lb-ft.

https://www.gixxer.com/threads/stock-k7 ... 72&slide=0

That's a K7 GSXR600 ('06'-07ish), and @ 9300 it's making what....less than 40 lb-ft? Sure, there's some drivetrain loss there but bikes are pretty efficient. I don't see you gaining 25% torque at that RPM point by playing with stock variations of heads and cams. The new latest and greatest GSXR600 is rated at ~45 lb-ft peak, and that's way above 9300.

This back of the napkin math shows you won't be racing against anyone with 90 hp that isn't heavily, HEAVILY cheating. Your competition will have a heck of a time making 80 hp if they're following the rules.
Let’s talk about percentages instead. Two simple modifications got +10% at 9000 rpm relative to stock (while obviously a massive loss at 14k rpm, but that’s irrelevant).
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

nitro2 wrote: Wed Mar 24, 2021 2:54 pm
ptuomov wrote: Mon Mar 22, 2021 9:24 am The exhaust is modified stock exhaust. With extra time and money, a full custom exhaust could be made from scratch. The chassis is different from a motorcycle chassis so there’s some obvious improvements one could make, beyond just lengths and diameters.
I'd toss that exhaust in the garbage, the OEM design (modified or not) is mediocre at any rpm. A 4-1 style is easy to build and will cover the rev range you need, it may not be the ultimate but will be good enough.

I basically agree, but I think trying other things with this modified exhaust is worth it. But ultimately, yes, run a 4-1 for this intended rpm range.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by Rick! »

ptuomov wrote: Wed Mar 24, 2021 1:25 pm
englertracing wrote: Wed Mar 24, 2021 12:40 pm Can you pick and choose what year parts?
For example
Allegedly Smallest ports and valves from newest
Smallest cams from oldest.
Can’t, since the service manual doesn’t instruct interchangeability.

However if you can get the head to rust and corrode, you can skim it no problem. And cam sprocket bolt holes that weren’t torqued properly can easily wear to oval shape. Etc.
You're not thinking "gray" enough. Does the service manual define "non-interchangeability?"
If rules were black and white, everyone would run the same.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

Rick! wrote: Wed Mar 24, 2021 6:51 pm
ptuomov wrote: Wed Mar 24, 2021 1:25 pm
englertracing wrote: Wed Mar 24, 2021 12:40 pm Can you pick and choose what year parts?
For example
Allegedly Smallest ports and valves from newest
Smallest cams from oldest.
Can’t, since the service manual doesn’t instruct interchangeability.

However if you can get the head to rust and corrode, you can skim it no problem. And cam sprocket bolt holes that weren’t torqued properly can easily wear to oval shape. Etc.
You're not thinking "gray" enough. Does the service manual define "non-interchangeability?"
If rules were black and white, everyone would run the same.
Everyone is basically running similar top speeds, but since we have the best driver it would be a shame not to also have the fastest car. Because we can.

The driver being great also means that we can’t go anywhere where we risk DQ. It’s not worth it, given the circumstances. So this car is going to be like Caesar’s wife, cost irrelevant but above all reasonable suspicion.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by LoganD »

ptuomov wrote: Wed Mar 24, 2021 6:37 pm
LoganD wrote: Wed Mar 24, 2021 2:24 pm 90 hp @ 9300 RPM is just under 51 lb-ft.

https://www.gixxer.com/threads/stock-k7 ... 72&slide=0

That's a K7 GSXR600 ('06'-07ish), and @ 9300 it's making what....less than 40 lb-ft? Sure, there's some drivetrain loss there but bikes are pretty efficient. I don't see you gaining 25% torque at that RPM point by playing with stock variations of heads and cams. The new latest and greatest GSXR600 is rated at ~45 lb-ft peak, and that's way above 9300.

This back of the napkin math shows you won't be racing against anyone with 90 hp that isn't heavily, HEAVILY cheating. Your competition will have a heck of a time making 80 hp if they're following the rules.
Let’s talk about percentages instead. Two simple modifications got +10% at 9000 rpm relative to stock (while obviously a massive loss at 14k rpm, but that’s irrelevant).
So you go from 39 lb-ft to 43 lb-ft. You've still got 19% to go on top of the gain you already made! I'm just saying that if your competition is actually making 90 hp at 9300 then they're very obviously cheating. You won't get that number with intake and exhaust, the stock stuff isn't leaving 30% on the table. This isn't some 1950s design. You'd need a more major internal engine change, at the very least camshaft changes.

I think you should pursue a better intake and exhaust, but you need to be realistic about where you are and where the competition actually is. If they're truly making 90 hp then you should explore other avenues, making 150 hp/l at only 9300 rpm is an impressive feat with a stock "long block". That'd be like adding and intake and exhaust to a new 911 GT3 and pumping out 600 horsepower.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

LoganD wrote: Thu Mar 25, 2021 8:06 am
ptuomov wrote: Wed Mar 24, 2021 6:37 pm
LoganD wrote: Wed Mar 24, 2021 2:24 pm 90 hp @ 9300 RPM is just under 51 lb-ft.

https://www.gixxer.com/threads/stock-k7 ... 72&slide=0

That's a K7 GSXR600 ('06'-07ish), and @ 9300 it's making what....less than 40 lb-ft? Sure, there's some drivetrain loss there but bikes are pretty efficient. I don't see you gaining 25% torque at that RPM point by playing with stock variations of heads and cams. The new latest and greatest GSXR600 is rated at ~45 lb-ft peak, and that's way above 9300.

This back of the napkin math shows you won't be racing against anyone with 90 hp that isn't heavily, HEAVILY cheating. Your competition will have a heck of a time making 80 hp if they're following the rules.
Let’s talk about percentages instead. Two simple modifications got +10% at 9000 rpm relative to stock (while obviously a massive loss at 14k rpm, but that’s irrelevant).
So you go from 39 lb-ft to 43 lb-ft. You've still got 19% to go on top of the gain you already made! I'm just saying that if your competition is actually making 90 hp at 9300 then they're very obviously cheating. You won't get that number with intake and exhaust, the stock stuff isn't leaving 30% on the table. This isn't some 1950s design. You'd need a more major internal engine change, at the very least camshaft changes.

I think you should pursue a better intake and exhaust, but you need to be realistic about where you are and where the competition actually is. If they're truly making 90 hp then you should explore other avenues, making 150 hp/l at only 9300 rpm is an impressive feat with a stock "long block". That'd be like adding and intake and exhaust to a new 911 GT3 and pumping out 600 horsepower.
Don’t get hung up on the number, it’s from a dyno that adds a car like correction factor to it. That makes it at least 10% happy. 90hp on that dyno is where the competition is. Let’s think I’m terms of the % improvement in torque relative to stock. Longer trumpets and exhaust reducer inserts added 10% torque at 9000 rpm, same dyno same day. There’s nothing ideal about those changes, but the changes were extremely cost effective and got us basically to that “90hp” @ 9300 rpm where the competition is on the same dyno. I think there’s more to be gained within the rules with more time and $$$.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by Momus »

You require 50.8 lb/ft of torque to make 90 hp at 9300.

That works out a BMEP of 195 psi.

It is a high figure for a 4 valve bike engine.

I would also be suprised if any one had actually achieved that given the constraints.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

Momus wrote: Sun Mar 28, 2021 3:53 pm You require 50.8 lb/ft of torque to make 90 hp at 9300.

That works out a BMEP of 195 psi.

It is a high figure for a 4 valve bike engine.

I would also be suprised if any one had actually achieved that given the constraints.
Did you read the above post on the scaling and the dyno?
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by Momus »

ptuomov wrote: Mon Mar 29, 2021 11:40 am
Momus wrote: Sun Mar 28, 2021 3:53 pm You require 50.8 lb/ft of torque to make 90 hp at 9300.

That works out a BMEP of 195 psi.

It is a high figure for a 4 valve bike engine.

I would also be suprised if any one had actually achieved that given the constraints.
Did you read the above post on the scaling and the dyno?
Yes.
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by ptuomov »

Here’s the result from some more extensive exhaust modifications. With different inserts, one can get a lot more power in the 7000rpm valley with only a tiny drop of peak power at 9300rpm. Soon, they are at a point where they know what kind of full custom exhaust to make:
0C7BEAE6-5DF7-49CF-9052-4F51DEEB6E56.jpeg
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Re: 13100 rpm fourbanger restricted to 9300 redline

Post by gruntguru »

If it turns out you need less cam duration, some "sloppy" seat work could reduce the low-lift flow. Pocketing, sharp edges on seats etc.

Does it have to be a GSXR? No doubt Suzuki make de-tuned versions for naked bikes etc.
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