78 or 90 mm intake for cam only soon to be H/C car?
03-31-2004, 01:37 PM
#1
78 or 90 mm intake for cam only soon to be H/C car? Really serious about buying a FAST intake, but need to decide which size I need. The car is currently a cam/bolt-on car, but I plan to do heads and bigger cam down the road. I highly doubt that I will ever go bigger cubes on the car. Which size would be more beneficial? Thanks.
03-31-2004, 02:06 PM
#2
nice #'s already!!
I have heard from my tuner/builder the 78mm is ideal unless you have over 400 cubes..you have plenty of options for TB with that intake as well compared to the 90mm..some people might say to go with a 90 but you would be wasting your $$
I have heard from my tuner/builder the 78mm is ideal unless you have over 400 cubes..you have plenty of options for TB with that intake as well compared to the 90mm..some people might say to go with a 90 but you would be wasting your $$
04-02-2004, 12:21 AM
#5
Its hard making a decision when dealing with this much money. I have 2 particular members saying that the 78mm is ideal for my set up even though Im going to do heads down the road, but then again Ive also read that when you do a pretty mild to hot heads and cam set up, that the 90mm set up is more beneficial. I dont mind spending the extra money if thats what I need. Honestly, Id like to go wtih the 90mm intake and tb, but if its absolutely not necessary even with a pretty hot h/c setup, then I wont go that route.
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04-02-2004, 04:51 PM
#9
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Originally Posted by DVST8OR
Still don't understand why you would go 90mm when the biggest MAF and lid out there is 85mm. And lots of people have problems with those.
04-02-2004, 04:57 PM
#10
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www.ls1howto.com has the frequency values to input in edit so that maf can run accordingly*fixed link
Last edited by WILWAXU; 04-02-2004 at 06:56 PM.
04-02-2004, 05:19 PM
#11
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Originally Posted by DVST8OR
Still don't understand why you would go 90mm when the biggest MAF and lid out there is 85mm. And lots of people have problems with those.
No problem with my 85mm maf. Why would you want to go with a 78mm if you had a 85mm maf and air lid then you T/B and intake would be the restriction
The way I see it if the 90mm will only flow 85mm with thw 85mm maf thats better than 78mm and besides I'm sure the 90mm maf's and lids will be out soon.
04-02-2004, 05:43 PM
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Originally Posted by smokin' joe 00 ss
besides I'm sure the 90mm maf's and lids will be out soon.
Well when those come out then I will see the point of getting the 90mm. But even then it will take some convincing / strong numbers to back it up before I will be sold on it. Bigger is not always better. Sometimes bigger is too big.
04-02-2004, 06:22 PM
#13
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i just got my 78mm LSX yesterday and i have a TSP 231/237 and AS stage 2.5 5.3L heads comming. The reasons i choose the 78mm over the 90mm is 1 because by the time i get finished replacing all the parts i've already bought MAF,LID then add the 500.00 extra for a 90mm TB and the additional 100 bucks for the 90mm vs the 78mm i just did not think it would be worth it! Now it may be proven in the future that i made the wrong choice but as i asked many times for a 78mm vs 90mm back to back test NOT one person gave me a solid ansewer! so for everyone to say 90mm is the way i do not understand this because we really have not seen the fast 90mm TB or the 78mm tb tested on the LSX manifold & until we do no one should assume that bigger is better. Just my .02 Later Shawn
04-02-2004, 07:39 PM
#14
For a couple years now the LS6 intake has been the way to go with most setups. It's flowed great for most of them, but for a S2 H/C I would just go with the 78mm if you need to have one.
90 may or may not be too big. But we've all seen the dyno charts that show the 78mm LSX gaining anywhere from -1 to 10 hp. It's the tune that gets you the extra 20rwhp with the intake swap. I can't see the 90mm being worth it unless your running a grand am cam and some big *** ls6 heads. Obviously for the big 6.0s and other big bore motors, the 90mm is probably the hot setup.
Rob
90 may or may not be too big. But we've all seen the dyno charts that show the 78mm LSX gaining anywhere from -1 to 10 hp. It's the tune that gets you the extra 20rwhp with the intake swap. I can't see the 90mm being worth it unless your running a grand am cam and some big *** ls6 heads. Obviously for the big 6.0s and other big bore motors, the 90mm is probably the hot setup.
Rob
04-03-2004, 04:38 AM
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Originally Posted by DVST8OR
Well when those come out then I will see the point of getting the 90mm. But even then it will take some convincing / strong numbers to back it up before I will be sold on it. Bigger is not always better. Sometimes bigger is too big.
Well I'm not trying to convince you of anything I did the research and talked to the right head porter and with the flow #'s they got on a 90mm intake with stage 2 heads that was enough to convince me 90mm was the way to go.
04-03-2004, 07:22 AM
#16
I'd go with the 90 mm if I were to buy one. I've got plenty of gear in my car, and if I loose some down low, but pick up from mid to top that's fine. Plus my next combo will need the bigger TB. Why buy twice, get the 90mm the first time and be done with it. 
Bruce
Bruce