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Guys,

 

I never managed to get on the group buys for the James Thagard intake manifold a few years back and now a friend and follow member is selling his on ebay.

 

Very tempted but not too sure whether to go for it or not. I know Rick Bowers had one of these but I can't find his thread with the dyno numbers, which would help.

 

Given the photos from the link below, what do you reckon of the design or have you had any personal experience to share?

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300573385805

 

Thanks.

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Guys,

 

I never managed to get on the group buys for the James Thagard intake manifold a few years back and now a friend and follow member is selling his on ebay.

 

Very tempted but not too sure whether to go for it or not. I know Rick Bowers had one of these but I can't find his thread with the dyno numbers, which would help.

 

Given the photos from the link below, what do you reckon of the design or have you had any personal experience to share?

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300573385805

 

Thanks.

 

 

I know Garrett Maddox had one on his L28ET 280Z and I believe he made over 500 wheel HP before the motor went south. Maybe he will chime in as well.

 

I found one of Garrett's Dyno Posts.Not the most power it made but I think this was still with the stock cam.

 

http://forums.hybridz.org/index.php/topic/48627-some-new-dyno-numbers/page__hl__%2Bthagard+%2Bintake+%2Bmanifold

Edited by wigenOut-S30
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I cannot remember if Rick Bowers ( Speeder) had tapered runners or not on his but I remember him doing a dyno test before and after the manifold and gained some pretty significant power. I tried searching but it is almost useless to search hybridZ for previous posts from someone.

 

Edit** found one of Ricks Posts with Pics.. His did not have tapered runners.

 

http://forums.hybridz.org/index.php/topic/28200-new-engine-update/page__p__218454__hl__%2Bthagard+%2Bintake__fromsearch__1#entry218454

Edited by wigenOut-S30
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I cannot remember if Rick Bowers ( Speeder) had tapered runners or not on his but I remember him doing a dyno test before and after the manifold and gained some pretty significant power. I tried searching but it is almost useless to search hybridZ for previous posts from someone.

 

Edit** found one of Ricks Posts with Pics.. His did not have tapered runners.

 

http://forums.hybridz.org/index.php/topic/28200-new-engine-update/page__p__218454__hl__%2Bthagard+%2Bintake__fromsearch__1#entry218454

"

those runners appear at least 1/4" bigger in diameter

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"

those runners appear at least 1/4" bigger in diameter

 

Have you seen these manifolds in person? Well I have and the Inside Diameter are a HUGE improvement over the stock tiny runners. Im going to call Rick to see if he will post up his before and after dyno experience with this manifold.

Edited by wigenOut-S30
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Garrett bought that manifold from me. That was the ONLY manifold that ever had tapered runners. James finished it after I told him I wanted to buy it.

 

"only" & "ever"

 

That's like "always" & "never"....

 

"Of James' manifolds" would be a fair qualifier. There are more fabricators out there...

 

 

That being said, 'nice piece'! The stock manifold supports a lot of horsepower (JeffP, for instance), but even Jeff's Extrude-Honed Stock Manifold is (by flowbench testing) flowing 30CFM @ 25" H2O less per hole than his head is capable of flowing. That kind of increase is substantial. Jeff admits his hard-headedness on this point, and it was only because he wanted to see if it could be done that he did it. For a little more than the cost of the extrude-honing you could apparently buy that manifold. Seems like a deal to me if you don't need that stock-looking manifold under the hood!

 

Not too sure on the advertising of the object being '240/260Z ALL' applicable...it's an EFI pattern manifold so you need a head with the four-bolt top attachment. It is not a 'universal' flange like A Hillborn, Eggers & Vickers, or some of the other aftermarket flanges now available which have the Carb Pattern Stud Holes. B)

Edited by Tony D
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"only" & "ever"

 

That's like "always" & "never"....

 

"Of James' manifolds" would be a fair qualifier. There are more fabricators out there...

 

 

That being said, 'nice piece'! The stock manifold supports a lot of horsepower (JeffP, for instance), but even Jeff's Extrude-Honed Stock Manifold is (by flowbench testing) flowing 30CFM @ 25" H2O less per hole than his head is capable of flowing. That kind of increase is substantial. Jeff admits his hard-headedness on this point, and it was only because he wanted to see if it could be done that he did it. For a little more than the cost of the extrude-honing you could apparently buy that manifold. Seems like a deal to me if you don't need that stock-looking manifold under the hood!

 

Not too sure on the advertising of the object being '240/260Z ALL' applicable...it's an EFI pattern manifold so you need a head with the four-bolt top attachment. It is not a 'universal' flange like A Hillborn, Eggers & Vickers, or some of the other aftermarket flanges now available which have the Carb Pattern Stud Holes. B)

 

This thread was referring to a specific manifold builder. I edited my post.

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Wow, this is taxing the old brain to dredge up stuff from years ago.

 

We never dyno'd my car with the Thagard manifold, but did a pretty scientific study with datalogs. Specifically, I datalogged rpm, MAP, and wideband AFR on the original ported N42 manifold with a 60mm throttle body as a baseline. I then installed Jame's manifold with the same throttle body and injectors, and made sure that the boost setting was the same. We used a good closed loop HKS boost controller which needed no readjustment, and pulled another datalog. With all other conditions the same, We recorded something like .6 AFR leaner in the higher rpm areas( more than 4500 or so up to redline as I recall)under boost. Interestingly, AFRs were actually a little richer than the stocker mani in the lower RPM cells under boost. We were testing at about 17 psi, at about the 400whp level.

 

James postulated that,when we tuned for the additional airflow, we would gain somewhere in the neighborhood of 35-40 hp. He actually posted some graphs on his old website as I recall. I don't remember if the power gain could be felt by the butt -in fact the boost at higher RPM at some expense of spoolup mitigated the enhanced power - but definitely could be measured. We never backed up these experiments with dyno numbers or comparative dragstrip times.

Edited by speeder
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  • 2 weeks later...

I made approximately 10 of those manifolds and sold them for ~$300. This was more for fun and to support the community. As far as the tapered runner manifolds I only made one of them, but I did also make one with velocity stacks.

Velocity Stack Manifold

Ebay Intake

TwinTurbo Intake

RickBower Love

 

For the manifold on ebay, I took a stock manifold and then cut off the runners about 1.5" off the flange. I then overlaid the stock gasket and traced the port size. Using a boring bar I ported the runners to match the stock head gasket. I then took a similar ID aluminum tubing to fabricate new runners and then made the plenum.

 

I think Rick is correct that we leaned out AFR by ~0.6. However, I think the car also picked up 4mph in the 1/4 during the SEZ event. Good Times!

regressionplot.jpg

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