Getting more low end torque 450

[bakirkwold]

Is there anything I can do to get more low end torque on a GS450? Advance intake cam a bit? My bike as far as the engine goes it stock.

[rapidray]

Sorry but if you want more torque get a bigger bike. Cam timing & compression will add torque. A 3 tooth larger rear sprocket will make it FEEL like it has more torque but you will lose a little top speed. On a 450 how often do you go 80? Ray.

[rich001]

I have been reading about a really fascinating intake mod that our dirt bike brethren have tried. Apparently, some of them place a horizontal plate into the intake, on the air cleaner side of the carbie. The idea, as I understand it, is to direct and increase the intake velocity at small throttle openings and thus improve low speed response and torque.

I make NO claims re its effectiveness but I LOVE these sort of simple mods. The dirt bikers that try it rave about the improvement. I have a GS1150 so the last thing I need is more torque but I cannot resist trying this type of thing ---- just because I can.

I suggest you Google ''Jamesnow mod'' and make your own decision. There are several other variations on the theme but they all work on the same idea.

Good luck
Richard

[bakirkwold]

I go 80 sometimes. Not too much though. I looked at that mod a little bit. Some people say it works others do not.

[pete]

I found the 2 into 1 pipe I got made has done something for the mid range on mine... it used to get up and go around 5000 - 5500 RPM with the stock 2 into 2, but now with the K&N's and pipe it's around 4000 - 4500 RPM...

Definitely not an increase in torque but much better around town I feel.

This is all seat in the pants stuff though, never had her on a dyno before or after...

[AJ]

What do you have for an exhaust pipe? If you have a "free flowing" aftermarket exhaust, you usually give up some low-end grunt.

The easiest (and cheapest) thing to do is a bigger rear sprocket, as RapidRay suggested. Heck, even the Hayabusa guys do this, and the Busa is a torque monster if ever there was one.

Beyond that, a compression bump by milling the head or some high compression pistons. If you mill, you'll have to slot your cam sprockets to re-time the cams. A lotta work, and you won't be that impressed with the results.

[tkent02]

Another member is putting a 650 top end on a 450...

[AJ]

Another member is putting a 650 top end on a 450...

That's one of 3 or 4 times I have heard reference to a GS650 twin here on GSR. Can someone point me to a link for this bike? All the GS-series bikes I know of were four cylinders for 550 and above.

I know Kawi made both a 750-4 and a 750-twin in this era, but the twin was a rare bird. Yamaha had it's famous 650 "Brit bike" engine.

[Mekanix]

G"R"650 Tempter is the one they mean I believe.

http://en.wikipedia.org/wiki/Suzuki_GR650_Tempter

[AJ]

G"R"650 Tempter is the one they mean I believe.
http://en.wikipedia.org/wiki/Suzuki_GR650_Tempter

Cool! I have never seen one of those. Must not have been a big seller, but that engine makes more sense than the Suzuki Savage/S40 model with the "half an Intruder" engine.

If the OP wants more torque and lives near Antigo, Wisconsin, there's the 650 on ebay right now going cheap!

http://cgi.ebay.com/ebaymotors/1983-Suzuki-Tempter-GR650-GR-650-Low-Miles-Nice-Project-PRICED-CHEAP-L-K-/170817473673?pt=US_motorcycles&hash=item27c583cc89

[twistedd49]

I've been looking into the 650 top end. A few guys on here have done it or know what is needed. I don't get on the computer much, but I have been able to answer my ?'s by searching. So I don't post that much. The knowledge & info on here is staggering though.

[TheCafeKid]

That's one of 3 or 4 times I have heard reference to a GS650 twin here on GSR. Can someone point me to a link for this bike? All the GS-series bikes I know of were four cylinders for 550 and above.

I know Kawi made both a 750-4 and a 750-twin in this era, but the twin was a rare bird. Yamaha had it's famous 650 "Brit bike" engine.

Rare? I have two of em in my storage garage. I think they were called "CSR"s or something like that. I've seen quite a few of em. Neat look but slugs... Seem to be an entry level bike perhaps? Single brake, not a lot of trim, wire wheels etc..

[Mekanix]

Using a 650 top end will be difficult !

1 the stroke of a 650 is 70mm
The gs450 is 56.6
2 the case bore is too small for the 650 sleeves to fit
3 just installing a 650 top end will make it a 527 with a 7.5:1 compression ratio

There is just too much volume in the combustion chamber.


So... the way to do it is: Either like I am, or like this:

1. Use a gs500 block and bore it from 74mm to 77mm and get some GR650 pistons (or have cp pistons make some for you UP to if they are too hard to find)

2. Use the gs500 head or gs450 (depends if you want to mess with exhausts or not)

3. Bore out the gs500 steel head gasket or have Cometic make you one.
and use the gs500 base gasket.

4. Reassemble the engine and check for any problems with clearances.

5. Do the math to figure out the new compression ratio and see if its something that you can live with. Just doing it quickly I can say it will go from 9:1 to 9.6:1
(I'm not sure what the difference between the 450 and 500 combustion chamber volume is so that number is a close guess)

6. Choose a set of valves you like (if your going bigger) and check your valve clearances.

7. Assemble and you get this:

http://www.youtube.com/watch?v=tQEVHd1cSyw

[pete]

Aaaaaah the 527 beast rears it's head again... that thing is definitely a beast!

The only thing he doesn't show properly in that video is how he got around the frame/exhaust port issue, but BIGYAM did that with his tracker and the GS500 engine so I know it can be done.

The guy with the 527 put a thread on here once, but unfortunately it wasn't in a technical forum and it got purged...

[AJ]

Rare? I have two of em in my storage garage. I think they were called "CSR"s or something like that. I've seen quite a few of em. Neat look but slugs... Seem to be an entry level bike perhaps? Single brake, not a lot of trim, wire wheels etc..

You crack me up, CK. When I grow young, I wanna be you!