Kelly.

first let me say that i love this forum. i have been doin alot of reading on here, and i cant wait til the search function works again.
i am currently a honda guy making 440hp/362tq on a underdog 1.6 sohc motor, so im not a complete turbo noob, just a turbo v8 noob

but recently i have been really looking into boosting a v8,

i have a chance to pick up a pretty nice TA with a 383 lt1 in it.

everyone i talk to says "just buy the LS1" and im just trying to get a few answers,

whatever v8 i get i will be turboing it,
ill rebuild the motor, new heads and turbo cam.
im looking to run mid-low 10s on slicks and possibly a high 10 on dot bias plys, in a 6speed =/ , maybe swap to auto later.

i was wondering if someone can answer a few questions before i dive in headfirst to the v8 world

since i will be rebuilding the motor, does it really matter what i start with?
im figuring that since the motor i will build will have a forged bottomend and aftermarket heads it should be as strong as a similar LS1, ( i havent looked at intake manifolds yet, but worst case ill get the stock one ported)
am i way off here?

i have read that the optispark on the lt1 is not that great. and has been known to die.
is there anything that i can swap to? maybe a msd box?

also are there any other know shortfalls to the lt1.

another thing that i am having trouble finding is a good tuning system for an obd1 lt1.
i have only found lt1edit and tunercat. neither of which seem very popular.
i can get autronic for a good price, but i was wondering if there are anything else out there that i should look into.

the car will be a weekend warrior with ~75%street/25%track duties

thanks in advance for everyones help.

Kelly.

bump

koolaid_kid

iTrader: (21)

You will always make more power with the LS1 with a similar configuration. Unfortunate for me, because I bought my LT1 new, and they came out with the LS1 the very next year.
The optispark is the Achilles heel of the LT1. Mine has not failed, but I have read many horror stories about them.
If I were starting fresh, I would buy an LS1, hands down.
I have LT1Edit, but would buy Tunercat if starting over. There are no other options.
If the LT1 you are looking at has a 383, chances are it already has a forged bottom end. If so, that would save you some money on the rebuild. If it is not already blown, of course.
Personally, I like the look of the LT1 TA better than the snouts on the LS1, but that is a matter of taste.
If you are looking for those times, expect to put a rearend in it. The stock ten bolt just won't hold up.
Best of luck, and keep us posted.

Dragframe

iTrader: (14)

its a SBC.... that sums it up....

ls1 onw is great.. but not god...

for your goals... and with your plans (rebuild, heads/cam)... it (the lt1) will suit you perfectly

engineermike

The bottom ends are pretty close in strength. The LT1 has the advantage of 5 bolts per cylinder so it can handle more boost. The LS1 has the advantage of 6 bolt mains. You can convert the LT1 to 4 bolt, but it still won't keep the cap in place as good as the Y block with 6 bolts. I would like to point out that the fastest stock block LT1 (8.0) is still faster than the fastest stock block LS1.

I'm running a stock Opti with an MSD cap and rotor with a Crane HI6TR. This setup has proven to be pretty reliable and good up to 25 psi boost.

Any of the FAST XFI, DFI, etc. systems will work and they are plug-n-play with the White Racing harness, but are expensive. I plan on trying a MSII one of these days because you can't beat it for the price ($400). However, for your modest goals, the stock ECM will work. I've been 9.9 at 146 mph on the stock ECM. TunerCAT, LT1edit, and TunerPRO all let you fool with the same basic stuff, but none are as powerful as an aftermarket ECM.

Mike

Kelly.

Thank you,
i was looking around and was hoping you would chime in

My main reason for goin aftermarket ecu woiuld be to go MAP.
I get free tuning and basically free dyno time, so that helps a ton.

i will get some more info and questions and post them up.

thanks for the info so far!

Kelly.

damn i must have missed this when i was checkin it earlier =/

im wondering why you say you will always make more power on a ls1?
if i have the smae compression pistons, same heads, same turbo etc etc.
maybe im missing something though.


is there a standard "when the optispark dies do xxxx"
or do most people just replace it with an oem piece?

what dont you like about lt1edit?
can you run it speed density?

the 383 TA im looking at is already "forged" but i dont like the components that are in the motor. im sure they are better then stock, but i know they can be better.
the motor is also currently blown (powerdyne at 6psi) but being ran on a FMU =/


also any rearend suggestions?
i am not looking for the cheapest route, but i dont think a custom ford 9in is completely necessary either.

thanks for the help

engineermike

The big difference in power potential is the heads. The LSx style head will always make more power than the LTx head due to the port volume, valve angle, port height, etc. . . This is true when using pretty much any 23 deg head on an LT1. Unless you get into the $$$ raised runner or 18 deg stuff, the LSx will have roughly a 50 hp advantage over an LTx mod for mod.

I just bought a new GM Opti and put an MSD cap and rotor on it. Most just replace it with a new stock one. Some get the complete MSD unit, but it's expensive. They aren't as bad as people make them out to be.

You can run an LTx in speed density using any available tuning software. It's not that difficult, really. However, running it in 2 bar or 3 bar speed density is alot more complicated. It's been done, but even the professional tuners are scared of it. I'm going to attempt it one day on mine, but I'm not really expecting to succeed.

I spend a total of $1500 on my Ford 9". I couldn't see spending the $2500 that most people want. I bought a housing and axles from Thunder Racing for $1000. I got a new Trac-Lock and a new 3.00 gear set and installed them in a used 3rd member that I got for $50 (they are common). I even made the 3 channel ABS work for very little investment.

Mike

Kelly.

thanks again for the info mike,
im not familiar with the difference between the 2 heads (the deg thing) but ill look into it / ask around locally.
a 50 hp difference isnt that bigga deal at the hp im looking at (550ish)
thats only a few more psi of boost

i guess the optispark isnt as bigga deal as i was led to believe,

im sure my tuner will be able to get the 2/3 bar stuff working with whichever software i use. he has tuned a few high hp cars.


i didnt realize that a 9in was so cheap (in relative terms)
ill probably blow the current rearend ten rebuilt it


mike, you got a pm