421 in 88 vette suggestions
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From: W.V.C. Utah
421 in 88 vette suggestions
I have a 421 ready for a cam. I don't have enough money for a mini-ram so what size cam should I run with a stock ported intake. I have slp runners and a BBK 58 mm tb.
Drifting
Joined: Dec 2002
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From: Houston TX
Re: 421 in 88 vette suggestions (88421VETTE)
First of all, that motor will be effectively worthless with anything resembling the stock TPI manifold on it. If you have big tube or siamesed runners, you *may* get away with it. The stock runners, however, are the choke-point on that manifold.
If you have something bigger than the stock TPI to put on it, send me the info on the heads you have and where you want your peak power to be made, and I can give you some numbers.
If you have something bigger than the stock TPI to put on it, send me the info on the heads you have and where you want your peak power to be made, and I can give you some numbers.
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From: W.V.C. Utah
Re: 421 in 88 vette suggestions (CorvetteZ51Racer)
the heads and block are already I need to decide on a cam to put together. how hard is it to put a lt-1 intake on a 79 400 block? the heads are pocket ported and polished 2.05 intake and 1.62 exhaust springs on heads will take up to a 550 lift. I'd really like to port the stock plennum and buy a edelbroc tpi base. I have SLP siamesse runners and a BBK 58 mm tb already
[Modified by 88421VETTE, 12:34 AM 4/3/2003]
[Modified by 88421VETTE, 12:34 AM 4/3/2003]
Drifting
Joined: Dec 2002
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From: Houston TX
Re: 421 in 88 vette suggestions (88421VETTE)
Converting an LT1 intake to fit a TPI motor is possible, though it definitely involves some fabrication work, not to mention a small cap distributor.
On the heads, which heads are they? I need flow numbers to size the cam properly.
On the heads, which heads are they? I need flow numbers to size the cam properly.
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Re: 421 in 88 vette suggestions (88421VETTE)
I'd really like to port the stock plennum and buy a edelbroc tpi base. I have SLP siamesse runners and a BBK 58 mm tb already
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From: lakeland fl
Re: 421 in 88 vette suggestions (vader86)
Well, not "choked to death", but I used ported stock TPI intake and runners on my 406, along with AFR 195cc heads, '88 roller cam, and stock throttle body, and Ford SVO 24lb injectors. My peak torque moved from 3200 to 2700, and over 400 lb/ft of torque up to 4600 rpm. Since I rarely run the engine above 4000 rpm, it doesn't matter to me how much horsepower I do or don't make above 6000 rpm; For my specific application, which is going from 70mph to 120 mph on I-4, plus responsive around-town driving, the TPI is hard to beat.
Smaller area intakes don't "kill" an engine- just shifts the powerband in the RPM range; If you want to build a fun engine to drive, port out your existing TPI and enjoy it- if you want to come onto the forum and brag about how many horsies you make at 6500 rpm, spend the money on the big box.
Jeez, after reading the comments here on how miserable the TPI is, I am amazed my car started this am! :lol:
Smaller area intakes don't "kill" an engine- just shifts the powerband in the RPM range; If you want to build a fun engine to drive, port out your existing TPI and enjoy it- if you want to come onto the forum and brag about how many horsies you make at 6500 rpm, spend the money on the big box.
Jeez, after reading the comments here on how miserable the TPI is, I am amazed my car started this am! :lol:
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From: Cleveland Ohio
Re: 421 in 88 vette suggestions (johncazin)
I find it interesting that GM uses an induction set-up similar to the stock L98 (long runners), as well as ‘the’ original L98 throttle body on their RamJet 502. Maybe they know something we don’t?
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From: Springfield MO
Re: 421 in 88 vette suggestions (johnboy89)
you deffinately don't want the stock intake on it. If money is tight you can temporarily use the intake and tune down the motor to accomodate it. Then go with something close to a tpis mini ram or the stealth ram. I would hate to see all that potential power go to waste. Personally, I say that your springs aren't going to be enough. I have some parts ("509" 400 block and reher morrison 421 crank) and my plan is a tpis solid roller, mini ram, and brodix track 1 head. With a FAST system I see no reason why it woudn't make 500 at the wheels
[Modified by AS84, 10:13 AM 4/4/2003]
[Modified by AS84, 10:13 AM 4/4/2003]
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From: lakeland fl
Re: 421 in 88 vette suggestions (johnboy89)
"I find it interesting that GM uses an induction set-up similar to the stock L98 (long runners), as well as ‘the’ original L98 throttle body on their RamJet 502. Maybe they know something we don’t?"
Well, what do those silly GM engineers know about anything, anyway? I believe the stock throttle body was also used in the original 254 mph "Hammer" that Lingenfelter built, and also in the Calloway twin turbo cars- those seem to run ok. :D
Drifting
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From: Houston TX
Re: 421 in 88 vette suggestions (johnboy89)
I find it interesting that GM uses an induction set-up similar to the stock L98 (long runners), as well as ‘the’ original L98 throttle body on their RamJet 502. Maybe they know something we don’t?
