1987Formula350

I'm currently building a 355 with all the forged goodies and weiend 6-71 supercharger.
From what I've heard this engine should produce between 600 and 650 horsepower.(and thats without the nitrous) I know my 700R4 cannot handle this amount of power and I really don't want to go to a TH350 because I love driving on the Highway. Is a manual transmission the answer? If so, what one should I look for, Tremec, T5, T6 ? How hard is it to install a manual into a car that used to be an automatic?
Thanks

branz28

If you want a manual tranny go for the T-56. Plenty of LS1 guys running 400 - 600 and one guy in particular doing 950 horses, but his clutch gaves. That should give you a good idea of the power potential of the T-56. As for autos, i believe yank makes a nice automatic transmission. Might wish to check it out. www.converters.cc

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Gutted cat
-!AIR
-Gutted Air Boxes

ScreaminDeamin85Z

you are not as concerned about horsepower as you are with the amount of torque the engine will make. Notice on the specs of the trans it has a torque rating for it. Both the T-56 and The Tremec 3550 are rated at 450 ft/lbs and the Tremec TKO I beleive is rated at like 500 or 550 ft/lbs. I have seen videos of a guy with an LT1 that runs 10's on the stock T-56. He leaves the line at like 4000 grand, and that car definatley makes more the 450 ft/lbs.

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Brandon
"ScreaminDeamin 360"
350 60 over, TRW forged 9.83:1 pistons,Hooker Comp headers, crane cam 216/228 .484/.512, crane 1.6 RR's, ported plenum, home made ram air, 24lb SVO injectors, crane AFPR, all going through 3 inch mandrel pipe and a flowmaster.
New project-89 IROC-305 5spd...Jamex Springs...and thats just about it!Soon- 6 speed, Pro 5.0 shifter and 4.10's

http://ScreaminDeamin.cz28.com

branz28

Definitly agree with Screamin on the T-56, the LS1 guy hasn't made it to the track with his super shot of NOS but if i remember correctly his torque was also in the 900's. Like i said his clutch gave before he could finish, so that may be your only limitation.

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Gutted cat
-!AIR
-Gutted Air Boxes

vortech305

umm no matter how much goodies u put into a 355 with just a weind blower theres no way ur gonna pump 600-650 horses, maybe if ur pupming 18PSI of boost but i doubt that, especially since u said and thats withought the NOS.

87RS402

For whatever it's worth, QwikTrp is using the Tremec TKO 5-speed with his supercharged 468

AlkyIROC

If you want an auto with OD that will handle that much power then contact JET and buy a built up 4L80E. They're expensive and need a computer to operate. It's an electronic version of a TH400 with an overdrive.

Build the engine first and dyno it before estimating how much power it will produce. To build that much HP in a small block even with a blower, 92 octane won't be enough. You'll either have to run alcohol or VP C-12. Not good choices for a street car.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z SuperPro ET Bracket Race Car
461 naturally aspirated Big Block (times are for the current engine)

Best ET on a time slip: 11.447 altitude corrected to 10.99
Best MPH on a time slip: 119.42 altitude corrected to 124.86
Altitude corrected rear wheel HP: 493
Best 60 foot: 1.586

Racing at 3500 feet elevation with a typical race day over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

graebz28

iTrader: (5)

The 200R4 is another automatic option. That is what came in the GN's and TTA's. Art Carr is one guy who has lots of experience w/ sub 9 sec GN backed by the 200R4.

You should make up your mind of weather you want a full blown racecar or a street driver. You can have it all in one, but it is expensive. Plus, realize that every time you break something, there goes your transportation.

PS **** blowers! 600 hp N/A baby!!

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Michael Graeber

My Garage

1)83 Z-28 T-Top: Full cage, 9" w/ lad.bars, Midwest Engine Tech 406sbc,Strip Dominator, 1000-CFM Demon Carb, Phase VI Chevy Bowtie Heads 2.05/1.60, .630" Crower roller set-up, 1 3/4 coated Hookers 3" true dual exhaust th400, fuel cell & still not running

2)89 Formula WS-6 305 TPI Auto Daily Driver: minor motor mods, more suspension stuff. MODS

No one with a good car needs to be justified." JBMHR - Ministry

F-BIRD'88

Forget the overdrive. This motor won't
be happy cruising at 1400 rpm in OD. A 600+/-
hp Blown 355 should be good for 121 to 125mph
in the quarter and should peak out at around 6300 rpm. Pick a rear gear /tire combo to achieve this. With a 26" tire you would need
a 3.73 gear. On the hi-way at 60 mph you'll
be reving 3000 rpm. That's perfect for this engine. I'd use a th400 with a 3200/3500
stall converter. This combo won't get great gas mileage, but should cruise nicely with carfull carb tuning. By the way 600 hp in a blown 355 on pump gas (93/94 octane)is quite possible.
The secret is Low compression (7.3:1)
lots of boost and good breathing heads.
like fully ported darts or ar's. Jimmy Oddy
(Oddy's Perfection Engines) builds these in his sleep with off the shelf parts.

Bob86ZZ4

What about a built TH400 with a Gear Vendors overdrive on it? That's what I'm in the process of putting in my car. Very expensive but hopefully won't break.

Pro Built Automatics

How much nitrous are you planning on adding? If the total horsepower is around 750 then a 2004R setup can be made to work. I work with two people who have a couple of dozen "mid nine" Gran Nationals using their 2004R's, getting around 100-150 runs before having to go into the transmission again. I have have went thru quite a few of the Art Carr "so called" built to the hilt 2004R's & 700R4's, either because the units did not work right or were broke & Art would not fix them and if he did "fix" them they still were not working correctly. Some of these people had been back 2, 3 or more times and still their problems were not addressed. SAD! I have a few in the ten's and doing ok, but have not had a request for one going into a nine second vehicle. If I can be of help, let me know?