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Official Forklift Driver
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Discussion Starter #1 (Edited)
Hey folks. :buhbye:

This is not a bash or a rant, I'm just curious. :huh:

I'm reading the TPIS catalog and I'm looking at the ZZ-X cam. It says the cam gave them 408 hp, 451 ft/lb on a 350 w/ a factory TPI, stock TB / airfoil and (this is what I don't get) it pulls to 6300 rpm. They say nothing about it being chipped.

I thought the fuel cut-off was under 6k rpm's for one and secondly, is it possible to still have some power at that rpm?

My dyno graph shows power drop off at just under 4400 rpm's on an untouched TPI and stock cam. It's not a steep drop but I did lose 10hp over peak at 4800 rpm. I have since ported/siamesed the stock TPI and added the Hotcam and I feel the pull stop around 5k rpm's. This has me confused a bit.

Anyone have an answer to this? :huh:
 

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Official Forklift Driver
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Discussion Starter #3
I was thinking of dropping them a line but thought w/ all the different engine combinations I've seen on the web, I'd see if someone here has been there done that and get an independent answer.
 

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Official Forklift Driver
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Discussion Starter #5
Eric, your killing me! :rolling: :rolling:

Now that I have put quite a few miles on my 87 w/ the new mods and doing the mods in stages over the years, I'm getting a better understanding of how things work and what to expect. I know I need a new O2 sensor, a heated one, and I picked up the TPIS catalog to price check. The O2 location is now about 12" or more down stream than the stock location causing my computer to stay in open loop too long.

That information was given to me here but it's also in their catalog and Insider hints and tricks book and the O2 is well explained in the Corvette fuel injection book. I've always trusted their info and still do but I'm having my doubts about a few of their claims.

That one about the cam just jumped right out at me. If someone can tell me how to get this baby to rev up to 6300 I want to know. The cam I have is designed to rev that high but I can only get the thing to 5600, that's it. :( They advertise the large tube runners to have solid gains up to 5200. How can a stock TPI be better than large tube? :laughing:
 

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War Machine said:
I'm having my doubts about a few of their claims.

That one about the cam just jumped right out at me. If someone can tell me how to get this baby to rev up to 6300 I want to know. The cam I have is designed to rev that high but I can only get the thing to 5600, that's it. :( They advertise the large tube runners to have solid gains up to 5200. How can a stock TPI be better than large tube? :laughing:
Well put...you seriously should drop them an email....make sure you post the results...I love a good laughf!:laughing:
 

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You are going down the same road I was when I had my '87. It can be really confusing. I read their claims and I saw first hand on the dyno what people were getting. OK, so burning a new chip would probably do more but not much. First off, the stock TPI setup with Bigmouth intake and Large runners will help but not as good as their claims. I was sold on doing that until I saw other cars dyno runs. I needed (wanted) more than that would deliver. If you want to get that car to rev I would get a modded LT1 intake to fit in your L98 or a MiniRam intake if you want that thing to rev. You will pay on low end torque, but it will rev out like you want. Don't know if you have gears or not, but that will help with torque multiplication. The miniram would be the way to go. Just my .02 cents worth. I'm sure others will chime in on this.
 

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Official Forklift Driver
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Discussion Starter #8
I have 3.54 gears so the MR would go very well with my mods. I'm undecided on what intake I'm going to go with. I bought the Hotcam knowing that one day I will be doing an intake upgrade and the MR was the one I was thinking about using.

I'm going to drop TPIS a line and see what they have to say about this. I can't wait to hear what they have to say. :D
 

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Official Forklift Driver
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Discussion Starter #10
grumpyvette, when I installed the Hotcam I had intentions to put on a different intake. I ported/siamesed the stock pieces just to see what I could gain from it. I was looking at the MR and then the Stealth Ram came along. I was going to jump on that but I'd rather have something w/ a lower profile.

I think it would be VERY COOL if someone in the aftermarket would look into designing a LS1/6 style intake to fit the C4 style heads. I'm going to hold off a few years to see if someone makes something like this.
 
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