Thunder Alley Pipe and my new '03 CRF450

OK, I have heard so much talk about the Thunder Alley pipe and wanted to experience it for myself. I have personally ridden a 400EX with a stock pipe and a Thunder Alley pipe. After the ride, I could not believe the difference between the two. Actually, I don’t like quads in the first place and haven’t ridden it since the pipe change. Not because I am afraid of the amount of power the quad has now, it’s because I don’t feel comfortable on a quad in the first place and now you just increased the feeling even more by giving it more power with the pipe change. After hearing the raves about this pipe and getting to know Bob, I designed the website for him

I have shown up here in TT now and again answering questions about the pipe, as best I could, without actually owning something that had the pipe(besides my son’s XR50).

I finally purchased my ’03 CRF450 last Saturday. I am coming off a 93 KX250 that ran with the best of them but its old technology just can’t compete with the new bikes.

Being Anal, I refused to take the CRF out until all my aftermarket plastics, graphics, Thunder Alley pipe and Works Connection goodies arrive. Well, I got a little anxious and took it up and down the street a few times. I was amazed of the throttle response and power this bike had. It would lift the front wheel of the ground without breaking a sweat.

Today was the day Bob put on my new pipe. As soon as I got home, I pulled the bike off the trailer and fired it up. After it warmed up, I attempted to take it down the street again, to see if everything that I have been reading on here was true or just some crap because you just spent $250.00 on a pipe and by god it better add more power whether it did or not.

While in first gear I rolled on the throttle and rear wheel spun. I shifted into second, rolled on the throttle and the rear wheel spun. I shifted into third, rolled on the throttle and the rear wheel spun. I shifted into fourth and the rear wheel spun. I then stopped because I had gotten up to such a high rate of speed so quickly, I ran out of road.

The entire time I was thinking, “Holly SH__”. Needless to say, my stock tire will not last very long at this rate, who cares anyway. I rode the bike exactly the same way with the stock pipe as I did with the Thunder Alley pipe. You should see the tire marks down the street. My nieghbors must hate me. Hahahahahahahahahahaha

After this, I called a local shop who has a dyno. I have been waiting for someone to put up some facts. People CLAIM they have the dyno results but none of us ever see them. This will be done at my expense, as soon as I can get the extra money together. The only reason I am doing this is because I believe in the product. If I didn’t, I wouldn’t have offered to build his website for him. Now I know I made the correct decision.

Aint it bitchen?

Kinda makes ya wonder why the hell the factories dont just build them that way to start with huh?

You can look at this way, the 250 spent on your pipe is going to mulitply your tire bill by 125%. Not a bad side effect eh? :)

Yes, I am the person who programmed the Thunder Alley site. I contacted Bob after my friend bought a pipe from Bob, for his 400EX. After that, I decided to help Bob out and get his product out to the public. His old site was hard to locate, did not show up on any search engine and needed a facelift. I do this as a hobbie, for the right people.

BTW, I am not on Thunder Alley's payroll nor do I receive anything from the product sales.

Yours was a very helpful description of what this pipe does. It gives a massive boost in bottom end. It would be ideal for a pro in supercross, someone who needs and can control a big hit in the powerband. The biggest proponent of this pipe on this site (Therapture) is an expert in intermediate clothes, he obviously has the throttle control to take advantage of the hit.

On the other hand, I was attracted to the CRF over all of the other bikes because it has no hit and yet is still very fast. So when I picked a pipe, I wanted one that would keep the powerband but boost the power everywhere. Still easy to ride, but faster yet. What I did NOT want is wheelspin at every crack of the throttle and trouble keeping the front end down in good traction.

My point is you have to know what you want in power delivery and pick a pipe that provides that. This has always been the case with 2-stokes too. I've read enough TA info on this site to know it exactly what I didn't want, but it is obviously what many people do want. Remember one thing of the pants comparisons are worthless, any bike with a hit will 'feel' faster than one without. Having your arms pulled hard always feels fast. What matters is lap times and fatigue, and without the benefit of doing all the testing yourself, you have to match what you know about your riding style with the published test comparisons and feedback from other knowledgable riders. Even then you may not always get the 'right' one the first time.

One last thing - the stock pipe is probably fine for most riders. No need to change it unless you race and know what you want OR you love to add stuff for the cool factor. Nothing wrong with either, but most can just save the money.


Your point is well stated and I agree with most of it. The thing that everyone has told me, besides the pipe adding more power, is that the bike becomes easier to ride. I don't know how to explain it because I have not gotten to ride the bike on a track as of yet. The way it is explained to me is that the pipe spreads the power through the entire twist of the throttle. Instead of just hitting hard between certain RPM's, the power is even through the intire RPM range. Thus, having an even amount of power, nothing unexpected happens at a certain RPM. I hope I am explaining this correctly. If you ever have a chance to demo this pipe, do so and make a decision that will be right for you. No one knows what anyone else will like or prefer.

By the way, I do race in the Vet Beg. class. The only things holding me in this class are equipment (which has just changed) and being able to complete an entire series. Due to my work schedule, I am unable to race a complete series (my days off rotate).

Good explanation Todd. Sounds to me like it turns the crf into a 426f-450f type of powerband and takes away that smooth luscious one that the crf once had?

That's the whole reason I sold my 2 stroke and went with a 4 stroke - to have a linear type of power.

If I ever would get a pipe though I do believe it would be the thunder alley because I like helping the "little guy" out. If only they could make it quieter.

Actually now that I think about thought I read BOB at TA can taylor the pipe somewhat to your liking? Low,mid,top and smoothness of power delivery?

if you want to mellow out the hit, you can throw the spark arrestor in. seems to spread that power out a little. this pipe really does what it's supposed to do. i guess that's the bottom line. combined with great customer support, quality craftsmanship, and a price that's less than a PC, it's right for me. don't want to sound like i'm on TA's payroll or's just nice to see a genuine product through all the marketing and junk in the business. and from the little guy too.

apart from Price can someone give me a comparison from the Ramsey WB and TA...sound, power, delivery...the works...It sounds like these two are the best 2 performing systems in existence....I am getting a pipe soon...does anyone have the low down??? Thanks...DINGA

the TA is 45 extra for the SA. but it's not a screen type like the PC, big gun, etc. it's a turbine core design. a lot quieter with it in too.

"a lot quieter with it in too". That got my attention. Did it change the power characteristics much?

Your right about Keith, and last I heard he said he was going expert.

I, on the other hand, am nothing more than a fast novice. Locally in the top 5, big time, no where in there. Keith (therapture) let me ride his bike to decide if I really wanted to take the four stroke plunge. Not only was his bike fast, but it was easier to manage than mine is with a stock pipe. I do not know why with that monster bottom hit, but that bike rocked my world. Can't wait to get mine set up!!!!

Anyone know of Cobra exhausts? They make a similar reverse megaphone for ATVs. I have one on my Quadsport, and it does give huge bottom end hit compared to the stocker but it's LOUD.

I think I'd go with the TA too, if it was a little quieter. Cobra makes a quiet insert for their's.

I'm also interested in how much quieter the TA is with the SA, and if it changes the power that much.

Here's a link to the Cobra exhaust:

Pic of Cobra

todd92, I went with a C.Jensen Trust Fund Full Pipe. Hand tuned and 'recrafted' in central jersey.Perfect power for a barn moto. We need the abrupt power delivery to loft our bellys over the frozen southwick like whoops. We miss our 500's. mvmx

MVMX I must know you...we are talking about the same Chris Jensen I'm sure. I heard he got a CRF.

When I went to get my pipe, we talked about a quieter pipe. Bob said if you get the pipe with the spark arrester, he has the sound down close to or right at CA. regulations. The pipes without spark arrestors should be used on closed coarse tracks and will be louder than the ones with spark arrestors.

Ive seen some guys worried about adding a hit to the power band with the T/A and basically creating a YZ power curve out of the CR.

Well, my YZ hit got softer with the T/A. The bottom got easier to manage, but bigger and wider. Its kinda the only way I can explain it. I never tried the spark arrestor with mine, but its a trick piece. I had them send it to me with the normal open core. It seems to me that most of the noise from these bikes comes right out of the huge open core of the pipe. The S/A being a turbine core with no open direct exit is going to be quite a bit quieter.

You guys can call bob at 559-584-8109 and talk to him. He's got to be one of the nicest guys you'll ever meet.

i haven't put a lot of time on the bike with the SA in. but with time i put on it, i honestly couldn't tell much of a difference with the TA w/ SA in and stock exhaust. but that's a good thing-because now it's got the SA, and mirrors stock power quite well, and bob says it should be around 97-98 db (according to his sound tests). felt like maybe a wee bit better low end power than stock. but like i said, i haven't put enough time on it with the SA to carve the power comparisons in stone (when the front end popped up so easily with it in...i had to take the SA core out and test it with the straight thru core). i haven't had it sound tested yet in a park here in CA. when i do, i'll be sure to post the results. btw, the very end of the SA core is noticeably smaller than the straight thru core. maybe next weekend i can get to gorman to have it tested for sound.

todd92, Yea,I'm the old has been #6 cr's 500 + 250. you road with us at Florence and my whooped shore tracks. Only one Jensen! Has a 426,wrenched perfect,but not dirty, now that he's married and a contractor to the stars. You could be correct about the pipe, but I miss the 2/stroke hit and I can't deal with engine braking on our sand tracks. MV..mvmx6@yahoo..

Hello Marty...anyway I can't feel any more engine braking on the CRF than the 2 strokes. Being an old has been is still better than being an old never was. I've gotten quite a bit faster since I last rode with you, we got chased out of some sand pit in Tuckerton in 1999? I'll bet it would take you at least 2, maybe even 3 turns to get around me now. You guys should fly down here for a weekend and come riding, we have great tracks and I've got 2 extra bikes that are perfect. It's better than freezing your ass off up there. I'll send you an e-mail.

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