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80mm TB advantages/disadvantages

Old 06-10-2004, 09:04 PM
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Default 80mm TB advantages/disadvantages

As most of you know I will be looking into an 80mm TB for the car, I have recently been hearing some negative comments regarding the enlarged TB vs cost of the hardware.

I assume this will be something the GXP will get or is available considering its a 4.6L Northstar, now the 4.0L NS has one available thru RSM. Are there any other places that offer it? What are the HP gains on this hardware.

Basically is it worth the money

Taylor, I know you had one and liked it....anything specific to add?
Old 06-10-2004, 09:40 PM
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A better intake will help a lot with that, because you're allowing air to get in easier. Response will be improved as well.
Old 06-10-2004, 10:32 PM
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Well Jim, I don't have anything bad to say about my old RSM 80mm TB other than the cost, which really isn't too bad.

For those who don't know, I dynoed my stock 96 aurora, than added RSM intake, than thier 80 mmTB

Here'* my Dyno numbers, all #'* rated at the wheels and are the best of each test, 2 runs per.
Baseline---------190.0HP---196.7TQ
+Intake ----------198.3HP---202.9TQ
+80mm TB-------206.7HP---214.0TQ

Thats a gain of 16.7HP---17.3TQ at the WHEELS!!!
I gained +21.9hp and +20TQ at crank. THANK YOU RSM!! (numbers figured @ crank w/24% loss through the 4T80e tranny)
At the crank it'* now 271.9HP 282.8TQ !!!!!!
This is definetly a NOTICEABLE difference, over the stock #* of 250hp/260TQ, car has a new personality now
The nice thing about larger TB'* are the gains below the peek, more noticable all over than just an intake where more felt in higher RPM'*. This won't make it a rocket by any means but you will feel it. Later on I added a Corsa exhaust, which sounded fricking GREAT, and that really opened the car up, Jimbo already has the exhaust done. Aurora'* and Caddy'* are so bottled up to keep the noise down that a suprising amount of HP can be made when opening up both intake and exhaust.

Also for an Extra $100 they will port match the intake pleum to the TB also to 80mm, creating a straight 80mm path in, the intake manifold is already 80mm. My dyno #'* didn't have this port matched piece in, I added it later.

Sorry don't know of anywhere else that does them, What bad things have you heared?

I know the newer norhtsttars now come with an 80mm TB stock, put there different design and are drive-by-wire, so doubt it will be an easy conversion. FYI caddys with a Northstar from 96-03 all use the same TB as the Aurora, take that back only till 01 when they changed to different style, the 2nd gen aurora'* +01 use a different one also.

Hope that helps you Jim, just order the thing already!
Old 06-10-2004, 10:56 PM
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I figured that...

That should do nicely. Its getting done...before BonnevilleFest for sure!

Thanks for the info!
Old 06-10-2004, 11:04 PM
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hey now that bonniefest is about a month a way, I can just HAND YOU the service manuals for a 96 Aurora.

Curious what bad things did you hear?
Old 06-10-2004, 11:13 PM
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Ah yes, I was going to PM you about those things! ha!

As for the "thumbs down" info, read this

http://www.oldsmobileforums.com/foru...?showtopic=407

I was doing some Ebay searches for TB'* and could only find LS1 TBs avail, I wondered if it worked at all...
Old 06-11-2004, 12:14 AM
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Get that 75mm one off by Bfest and you have it sold my man
Old 06-11-2004, 10:34 AM
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that was my post, other usernames are dubya, or mike95aurora

i just dont think its worth 350 plus core, for many reasons

1) taylor, wasn't your stock throttle body very dirty when you replaced it? if so, this scewed the results some. i cleaned my throttle body about 6 months ago and i didn't even get everything because i didn't take it off the car. but i noticed a increase in pull especially low end, like a 36-40mph kickdown, which is pretty dead because it wont go into 1st gear anymore.

2) i saw spikes dyno, he had a low mileage 99 with intake, exhaust, highflow cat. i believe on one run he had 2 more hp, on one he actually lost power, he was very upset.

3)a 99 sts owner put it on his car, and felt no difference, didn't get any different numbers at the track. there was also another cadillac owner that said the same.

gm put a 74-75mm tb on a 4.6, because thats what they felt was necessary. a 4.0 would require a smaller one, but the fact that its the same, i dont think you'll need anybigger. how big is enough? doesnt the 6 or 7. somthing litre duramax use a 80mmtb? the Ls1 does, and we know that needs more air

a 99aurora owner besides taylor got 8hp i believe, not sure on the #'*, but we was happy

i would personally try it out, if it wasn't $350+ core and shipping (you need the $100 matched mounting plate) i just dont think its worth it. it should be 250 for both parts

if gxp speed parts come out, that part wont work on a aurora, they redesigned the entire intake on the 2000+ northstars.

if you do try it, clean your stock TB first, then put it on, let us know
Old 06-11-2004, 04:59 PM
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Well Mikes95Aurora, how the hell are you, didn't know you by your alias.

I can't argue with the cost, little steep, so is the intake, along with all their other stuff.
But I don't think that larger TB'* are bogus. I've talked to Greg Garnes MANY times on the phone, he was the other Aurora owner with a 98 about his dyno experiences, We also got Corsa to sell us exhuast systems togther. He dynoed his Aurora at least 4 different times, he messed with different gutted airboxes, little bit of ram air tube, and the 80mm TB, he had very similar numbers accross the board. aka, our dyno #'* where close at each level of mods. We both %100 agree that it made a Positive diffence. I have dyno numbers to prove it. We do you think there'* all these different Throttle body options for most popular cars, Imports for example, you can get say a 45, 50, 55 or larger (whatever), MORE AIR IN IS MORE POWER. I still plan on getting a throttle body for my SSEi with the positive results I've had in the past. Haven't decided if it will be L67 or LS1.

As for cost, a nice L67 throttle body is $400 bucks, and a LS1 conversion is $5-600, so inretrospect 350 with ported pleunm isn't that bad at all.

For the others didn't have such good success, I'd like to know there dynoing methods and conditions, and other mods. I'd question the dyno too, some are abused and not accurate either. For they caddy guy that didn't feel anything, I bet for sure there was an increase, just not that noticable in his heavly dampened Caddy. Also bet he didn't have an intake, and if he does it'* not a COLD AIR system, since I know nobody sells them you have to make one like I did, added heat alone from an open cone setup will make it seem not much difference. Comparitivly speeking L67'* make Knock and pull timing, more so when hot, but if things are cooler with same mods you won't get as much knock and car will be faster with same mods. Think Heat soak, car is sligtly slower weather you feel any difference or not.

I'm A believer that a properly done larger Throttle Body wither it be ported or a conversion is benefical. I wondered my self one day, that'* why I bought one and dynoed it.
Old 06-11-2004, 08:18 PM
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well, they did drop the price some, it was 299 for a while, and the core price went down too, i see its 100 for the core, wasn't it alot more at one time? wonder if they even have any cores. im curious, was there any real difference between your numbers and the "gutted air box"?

ive thought about givving it a try, you should have taken yours off and sold it!! maybe sometime i will order it, but i figure after shipping its $500 then $100 back for the core, thats a little chunk of change.

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