What next to beat 50-60 rwhp 450's

[450madman]

I enjoy riding the dunes and occasional hill shooting at Utah's Little Sahara sand dunes. Is there any mods left I can do to beat 50-60 rwhp 450R's up sand mountain and keep my 86 TRX250R from becoming a full drag/hillshooter? Here's what i've done so far: ESR 310 Cylinder & head with high comp dome (185 compression), ESR TRX9 port job, ESR TRX9R pipe & CT racing silencer, V-force 3 reed cage, 38mm Airstryker carb, K&N, 50/50 110 & premium fuel, 40:1 Klotz, 13/41 gears, 20" Skat Trak 8 paddle Haulers, full race width suspension (laegers, PEP, RPM Dominator), gusseted frame. I don't want a top end only drag bike. Reliability is important. I may be at the limits of my stock transmission. Saw a fully built ESR 370 on ebay. Would this be rideable on the dunes? Any info will help. thanks

[450madman]

Would a cr ignition and or a trx11 ESR pipe make a difference. I have a lot of bottom end that I could sacrafice a little bit of.

[CorvetteZ06]

Good setup, but sounds like you probably have the "cookie cutter" ESR porting. While I really like their products, and purchase/have a lot of them (jugs, pipes, intakes, billet parts), you will find that the cylinder has ALOT more potential than just the standard trx9 port job. If ya send that jug off to a top porter, C-leigh, BDT, etc.... there is a lot more power that can be unlocked. Besides that, a pwk 39 or larger carb will help your top end. Next step would to be go up in displacement, which will require you get your cases bored to fit the bigger sleeves.

[sand_blaster]

Neil would be a great choice on porting & although expensive the cr ign would be a great upgrade.

[etccb]

It looks like it is time to go bigger for you. CR ign, Stroker crank and port update with your cyl or a 330, 350 etc. On the 370 that you are looking at it depends on how it is set up to know if it is a drag only or a all around dunner etc. To just port what you have with the stock crank and cr ig may not take you all the way to your current mind set and desire, depends. 330pv to 350 4mil or 5mil stroker will do the trick.

[450madman]

Thanks guys. I ordered the ESR jug with the porting cast and had a reputable performance shop clean up the porting. Does the CR ignition make that big of a difference for the cost involved?

[troybilt]

Does the CR ignition make that big of a difference for the cost involved?

Yes it does, its one of the single biggest improvements you can make for the money. I've seen plenty of 310's in the mid 50's range, that's at the rear wheels. Open up the porting a little more. Cleaned up porting isn't enough.

[Pumashine]

Thanks guys. I ordered the ESR jug with the porting cast and had a reputable performance shop clean up the porting. Great, you are on the right track. My reputable motor builder gets the ESR cylinder unbored and a blank dome. It actually cost more than a bored cylinder and a cut dome. But then you know your bore will be perfect and the dome cut for your specified UCCR. This last part is where you will get the most power whether your building a 310, 410, or 510.

[jcs003]

the cr ignition is worth it for the reliability alone. excellent performance improvement too.

john

[450madman]

I have about $2200 more to spend on my R so I'm trying to figure out if I should go to a larger ESR cylinder kit and have trans work done to support it or mod what I have. If I go to a larger bore I might not have enough to do the CR ignition. Is there a magic bore size for my riding preferences? Has to be dune rideable, reliable, and beat up on the 4 strokes on the hill.

[tbone250r]

-------

[tbone250r]

I have about $2200 more to spend on my R so I'm trying to figure out if I should go to a larger ESR cylinder kit and have trans work done to support it or mod what I have. If I go to a larger bore I might not have enough to do the CR ignition. Is there a magic bore size for my riding preferences? Has to be dune rideable, reliable, and beat up on the 4 strokes on the hill.

Looks like a +4mm 330 is in your future (344)

Although I did just whoop on my buddies and their 52-53HP 450's last weekend :)

[derby]

^^^^ this guy is right. If the 330 were a geyser I would call it "old faithful". Not only is it reliable, it really offers the best bang for your buck... or pound... or euro. Combine that with the lighter weight of a 250r and you have a good combo.

[etccb]

I have about $2200 more to spend on my R so I'm trying to figure out if I should go to a larger ESR cylinder kit and have trans work done to support it or mod what I have. If I go to a larger bore I might not have enough to do the CR ignition. Is there a magic bore size for my riding preferences? Has to be dune rideable, reliable, and beat up on the 4 strokes on the hill.

You can do what you are after with that. 330cc to 350cc, 4mil to 5mil stroker, cr ig, and a carb with your other items that you already have will get you there. Make a call and you might even be able to get a combo type deal a little less then website price. A big bore pipe will not be required for that size build so you can run yours.

[450madman]

What brand cylinder do you guys recommend? Who do you recommend to get everything set up for me? I can install almost everything, I just need the case bored and everything ported and flowed to that set up. I have someone that can install the crank and I can install the top end.

[tbone250r]

What brand cylinder do you guys recommend? Who do you recommend to get everything set up for me? I can install almost everything, I just need the case bored and everything ported and flowed to that set up. I have someone that can install the crank and I can install the top end.

Get C-Leigh to do the porting. There are many others and im sure other people will chime in, but Neil @ C-Leigh Racing is an excellent option

[derby]

Which cylinder to use is a good question for the builder. You basically have 3 choices pro-x (if you can find a new one), esr or cp sphinx. All 3 will do what you want the question is cost to setup.

[Burns310r]

Which cylinder to use is a good question for the builder. You basically have 3 choices pro-x (if you can find a new one), esr or cp sphinx. All 3 will do what you want the question is cost to setup.

Im pretty sure you can still buy Pro X new still.. I bought one last year.

[8686]

I would keep the 310 cylinder, have it ported for broad midrange power since you want it more reliable and don't want a drag only engine. Bump the compression to run straight 110 octane. Swap the carb for a 40.5 PWK. Add a CR ignition if money allows. With the 20" paddles I think you may be running too much gear, too much shifting. I'd try 13/38 and see if that allows your bike to pull the gears longer.

[450madman]

Thanks for the suggestions. I decided to go with the 78mm X 72mm Sphynx top end with an 87-89 rod which should put me at 344cc. Also a 40mm Lectron carb, CR ignition, and maybe an ESR center mount trx9b pipe/stinger. Dennis Packard does amazing port work for Utahs altitude so he will do my porting and machine work.

[jcs003]

that sounds like a nice engine package. i want to do a 76mm x 76mm sphinx.

john

[8686]

Very nice!

[450madman]

It was pricey but the Packard built 344cc Spynx did the trick. On pump gas I kill heavily built 450's on the hill and i'm not far behind my dads 72 hp Raptor. There's a Trx11 pipe for sale locally that I would like to try but ESR told me that the Trx9R pipe i'm currently running would be a better choice for my setup because Packard left my exhaust ports a little lower for the dune riding I do. My compressions a little low at 165 so I might try a different dome to get me to 180-190 and try the TRX11 pipe. Anyone run this pipe on a dune built big bore bike with good results? Hoping to throw her on the dyno soon

[450madman]

Found out that the low on Packard's port job is at least as high as the highs on ESR's ports jobs. Anyone dyno a trx9 vs trx11 pipe?

[sand_blaster]

I would try the 11. Wonder how much lowend you would loose?