John Buttons
Member
- Jan 4, 2002
- 14
- 0
Anybody help me locate hard performance numbers for either the Thumper Racing, White Bros. or Yosh performance kits? Trying to decide between Thumper 435 and 470 kits vs Yosh. Thanks!
Dyno numbers for Thumper DRZ Kits?
- Thread starter John Buttons
- Start date
I'm going to go with the LA Sleeve 454 kit because it keeps the stock compression ratio, unlike the Thumper 470 kit which drops it to 11:1. The LA Sleeve kit is a 96mm piston compared to the 97mm Thumper kit, which is actually a 463. Wiseco makes a 92mm piston in 13.5:1 (416), but I don't want to have to run race gase. I sure would like to see a dyno comparison between the bunch. :think
John Buttons
Member
- Jan 4, 2002
- 14
- 0
- Thread starter
- #3
LA Sleeve
Didn't know that LASleeve had a mod for the DRZ. Do you have any idea what their asking price is and whether they, like Thumper Racing, include things like gaskets, stronger clutch springs, etc.? Curious that none of the mod vendors are publishing numbers for their kits. We know they have them as it is certainly got to be part of any diligent product development and testing. EMailed Thumper months back for the numbers.... no response. Maybe they rather not have the "gee whiz it feels fast" sells mechanism and internet press ruined by objective numbers - something akin to a great story ruined by an eye-witness. The money I have spent on mods and would with a kit is getting scary and I have reached the point where I could sell my DR, add the $1,000 for a kit,labor, blah, blah and just buy something less needy of help. Almost rather do that than spend more money on something I cannot get objective info on. Any help would be appreciated. Thanks!! PS. Love my bike and race it in GP's but tired of getting eaten alive exiting every corner by just about every other four-stroke. Maybe I should just recognize it for what it was meant to be.....and quit trying to make it what Suzuki ought to have brought to market by now.
Didn't know that LASleeve had a mod for the DRZ. Do you have any idea what their asking price is and whether they, like Thumper Racing, include things like gaskets, stronger clutch springs, etc.? Curious that none of the mod vendors are publishing numbers for their kits. We know they have them as it is certainly got to be part of any diligent product development and testing. EMailed Thumper months back for the numbers.... no response. Maybe they rather not have the "gee whiz it feels fast" sells mechanism and internet press ruined by objective numbers - something akin to a great story ruined by an eye-witness. The money I have spent on mods and would with a kit is getting scary and I have reached the point where I could sell my DR, add the $1,000 for a kit,labor, blah, blah and just buy something less needy of help. Almost rather do that than spend more money on something I cannot get objective info on. Any help would be appreciated. Thanks!! PS. Love my bike and race it in GP's but tired of getting eaten alive exiting every corner by just about every other four-stroke. Maybe I should just recognize it for what it was meant to be.....and quit trying to make it what Suzuki ought to have brought to market by now.
I think that the LA Sleeve kit comes with piston, sleeve, head & base gasket, and wrist pin and clips, but no clutch plates. I guess I'll find oiut if the clutch needs them. I race mine in SuperTT (Motard), flat track, and GPs, but I find that it is pretty competitive except on long straights. And then it's only fast guys on 426s, 520s, and "Abusabergs" that get me. I have thought about a CRF450, but the bank account says a big bore kit is more likely. I haven't got the pricing yet, but I think it's around $400 for the LA SLeeve kit.
Pete - A big bore will increase the area under the torque curve but it will move the torque peak down to a lower rpm. If high rpm power is the goal a big bore kit isn't the best path. It's value in terms of torque increase is well worth it though especially for the type of racing you are doing.
Think carefully before you let anyone sleeve that barrel. A huge amount of metal has to be removed to accomodate a sleeve and the integrity of the bore will be compromised.
Think carefully before you let anyone sleeve that barrel. A huge amount of metal has to be removed to accomodate a sleeve and the integrity of the bore will be compromised.
motormichael
~SPONSOR~
- Sep 26, 2001
- 111
- 0
DRZ Big Bore
I don't know about you guys, but my DRZ runs hot already. If I get into a slow or muddy section of track after a hard run it boils over. I built an XR630 two years ago. I loved and hated it. After a lot of head porting,bigger bore, and knifing and balancing the crank it put out 56 hp. Up about 16-18hp. over stock. The torque was up too. This motor ran way hot even with XR's Only big fins added.
I guess what I am saying is that I would think long and hard before boring the DRZ. It will mostly add bottom and mid power anyway. If you want top end, spend your money on Yosh cams,ignition box, port work and a good pipe. I would also spend the money on the balanced Falicon Super crank. I feel the DRZ has a lot of engine vibration. This mod on the XR was awsome. It was smooth as silk. This has to help build revs quicker.
I don't know about you guys, but my DRZ runs hot already. If I get into a slow or muddy section of track after a hard run it boils over. I built an XR630 two years ago. I loved and hated it. After a lot of head porting,bigger bore, and knifing and balancing the crank it put out 56 hp. Up about 16-18hp. over stock. The torque was up too. This motor ran way hot even with XR's Only big fins added.
I guess what I am saying is that I would think long and hard before boring the DRZ. It will mostly add bottom and mid power anyway. If you want top end, spend your money on Yosh cams,ignition box, port work and a good pipe. I would also spend the money on the balanced Falicon Super crank. I feel the DRZ has a lot of engine vibration. This mod on the XR was awsome. It was smooth as silk. This has to help build revs quicker.
Rich: Thanks for the comments, increasing the area under the curve and keeping the stock rev limit was my plan. The DRZ hits the rev limiter pretty easily stock, so bringing the curve down a little might help. This seemed to be the cheapest and possibly most reliable to me. Compared to higher compression or higher rpm. I can use the torque to get my large carcass off the turns and I can always gear up for top speed. The Yosh kit is way more $ and the've blown up a few.
As far as the sleeving, I'm having a friend with a lot of experience as a pro engine builder do it who I have a lot of confidence in. I've also been following a bunch of people who have installed the Thumper 470 kit and haven't heard of any problems yet.
motormike: I haven't had any cooling problems at all, even on tight 1st gear trails. But I live outside Seattle and rarely gets to 80 degrees and mostly it's much cooler, so I'm not too worried about it. I'm also just doing the bore, not any cams, head work, etc., so I don't think it'll be too bad.
As far as the sleeving, I'm having a friend with a lot of experience as a pro engine builder do it who I have a lot of confidence in. I've also been following a bunch of people who have installed the Thumper 470 kit and haven't heard of any problems yet.
motormike: I haven't had any cooling problems at all, even on tight 1st gear trails. But I live outside Seattle and rarely gets to 80 degrees and mostly it's much cooler, so I'm not too worried about it. I'm also just doing the bore, not any cams, head work, etc., so I don't think it'll be too bad.
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