Need personal opinions on LT1/S30 z...

[Guest 73Turbo240z]

Since my motor is gone when i put it up for the Pinks show, and since we bought the car back it looks like i'll probally lose all money rather than at least get a little back as was planned. I'm trying to decide what i want to do next... i'm not sure if i want to build another high strung turbo setup, it took alot of money, and alot of time, and while it was definately fast, i just don't know if i want to do it again.

 

A friend of mine said he has an LT1 out of a 94' cadillac with 78k miles on it, no harness or ECU, but the rest is there, and it's a non-vented optispark.

 

and then he has another LT1 w/ out optispark, 64k on it w/ harness from a Buick roadmaster.

 

I'm not really big into v8's, for a brief time i had a 305 TPI in a volvo, but thats about it. I've heard the OptiSpark systems are finnicky and unreliable, so i figured i'd ask you v8 guru's. I'm not a carb nut, never have been, so if i do go v8, i need it to be EFI.

 

Additionally in my pokings around here i've read alot about eprom burners and things like that, i guess i'll need to poke around the MSnS forums to see if an LT1 has been run on MSnS cause i'd like to use what i kinda already know in terms of EMS.

 

But basically what i need to know from ya'll, is what should i expect? What are the downsides to an LT1, what are the upsides? In a relatively stock application (we'll say stock LT1, CAI setup, block huggers, and full exhaust) what kinda performance can be expected from an S30). I want the performance figures to be similiar to where my turbo L6 was, cause if i come back out w/ my car and it's now got a low rumble but gets walked by the same guys i used to dust w/ the turbo L6, that'd be a bad deal.

 

Thats it really, just want to hear from those that have experienced it so i can decide what powerplant is going back into my car.

[Guest Ron]

I put a LT! Lingenfelter engine in my El Camino and never regreted it. I can tell you that GM ran the vent line to the Optispart distributor to miminize condensation that would form in there and shorten the life span. Your advantage is you will have the motor out of the car. You can install new optispark dist. wires and even water punp fairly easily. Once that is done, as long as the computer and engind are talking to each other and there is no mechanical problems, you should have excellent hp. torque and reliability. I am installing an LTI 6 speed in my 280, and expecting to have far more horspower than I'll ever use on the street. A wise old racer once told me how to make your car faster than anyones. Never show em how much you've got. Don't light the tires, just gas it a little as you leave. In their mind it will be faster that you could ever really make it. I would go with the thumper.

[LS1 240Z]

problems with the opti spark come from a worn out water pump leaking on it. vented optis cure that problem very well.

 

LT1s are cheap to buy and the parts for them are cheap becuase they are just an upgraded gen1 sbc. LT1 would also use the JTR mounts and any angled plug header for a regular sbc. for about $2500 you can get a new supercharger kit for the car, and it would be hella fast and with a M6 be very reliable and get 30 mpg. LT1s need high fuel pressure though, so you would need to upgrade your fuel pump

[Guest 73Turbo240z]

problems with the opti spark come from a worn out water pump leaking on it. vented optis cure that problem very well.

 

LT1s are cheap to buy and the parts for them are cheap becuase they are just an upgraded gen1 sbc. LT1 would also use the JTR mounts and any angled plug header for a regular sbc. for about $2500 you can get a new supercharger kit for the car' date=' and it would be hella fast and with a M6 be very reliable and get 30 mpg. LT1s need high fuel pressure though, so you would need to upgrade your fuel pump[/quote']

 

define high pressure? cause i already was running a fuel system for the L6 that was feeding 40psi base and a 1:1 AFPR so 61psi at full boost.

 

what about engine management, is it just guys w/ eprom burners? or have other avenues been persued, anyone have track times of a semi-stock LT1'd Z?

[Bartman]

Try to find a complete unit (harness, PCM, transmission of your choice, etc.) There are plenty of them out there so I think it's better and cheaper in the long run to find one the way you want it to start. I would try to find an F-body engine from a 95 or later so that you have the right accessories, ODBII, and a vented opti. I have a 94 and updated to a vented opti, so I know how expensive it can be!

 

 

Here's a link that talks about the vented opti, ODBII, etc.

http://forums.hybridz.org/showthread.php?t=90482

[Guest 73Turbo240z]

Try to find a complete unit (harness' date=' PCM, transmission of your choice, etc.) There are plenty of them out there so I think it's better and cheaper in the long run to find one the way you want it to start. I would try to find an F-body engine from a 95 or later so that you have the right accessories, ODBII, and a vented opti. I have a 94 and updated to a vented opti, so I know how expensive it can be!

 

 

Here's a link that talks about the vented opti, ODBII, etc.

http://forums.hybridz.org/showthread.php?t=90482

 

ahh i was hoping you'd chime in, i was poking around your website earlier today in fact trying to get a feel for what i'd be dealing with.

 

is there any MSD type solutions to bypass the opti? or is it pretty much mandatory?

[Guest 73Turbo240z]

i've never driven an LT1 powered vehicle either, so i'm trying to decide if they have reasnoble top end as i'd like to go w/ a stalled automatic setup to make it a pretty potent 1/4 car, not really concearned about top speed.

[Guest ON3GO]

you will have plenty of top end on a LT1 as long as you choose your cam/heads and gearing correctly.

LT1's are great easy/cheap ways to make power!

 

mike

[Bartman]

ahh i was hoping you'd chime in' date=' i was poking around your website earlier today in fact trying to get a feel for what i'd be dealing with.

 

is there any MSD type solutions to bypass the opti? or is it pretty much mandatory?[/quote']I think there is an MSD solution, but the vented opti is really a pretty good setup. I think it just has a bad repution from the earlier non-vented version. If you switch to an electric water pump you also are much less likely to have a problems with water leaking onto it.

 

The engine has tons of torque stock and with a light weight Z it does really well. I don't have any time's but there a couple of people that have posted some pretty impressive quarter mile times (but I think they've all been modified quite a bit). Now I'm doing some pretty healthy modifications to my setup as well, so I'm really looking forward to driving it again with the upgrades.

 

Look around some f-body and/or lt1 sites and you can find some pretty impressive quarter mile times with just a few bolt-ons. Then think about how much quicker you would be with a similar setup in a Z!

[mark]

Just dynoed my lt-1. 427 rwhp and 410 ftlbs of torque. Block huggers and duel 2.25 inch exhaust. It ain't stock though. It peels the skin off your face when you step on it.

[jbc3]

The Opti is not that big of a deal... daily driver in the wet weather, or one who washes the motor when it's hot and you are at risk, otherwise don't worry about it. I have one that I am running in my 280Z right now that has 140K miles on it (it is the vented version) You can buy the 95-97 front cover, opti and hoses to convert the older non vented Opti. You will need the cam with the longer dowel pin too, The issue is that both motors have the iron heads. Take the one with the computer and the harness. If the harness is 94 or newer, it has a flash prom and LT1-edit or Tunercat work well.... no pulling and burning chips. You can buy aluminum heads for ~200 - 250.00 and use them for a core and check out http://www.advancedinduction.com/AiHome.htm for heads and cams. Go with long tubes for the power. Get larger injectors , a larger Throttle body, CompR lifters and 1.6 roller rockers.

For a quick and easy deal on the wiring harness, call Dana at LT1350.com and have him set the harness up for you. (it's been argued that it can be done cheaper with alot of time, doing it yourself... to each his own, but I felt that my time was better spent doing other things.

I personally prefer the 6 speed manual tranny, but bolt on a built turbo-350 tranny with a big stall, throw some nitrous in it and hang on. The 4L60E transmissions have alot of issues with Big stall converters and OBDI computers. Those problems go away with the OBDII computers, but the OBDII tuning software is alot more expensive. (yes you can run OBDII computers on the OBDI harnesses and visa versa... you have to edit out some of the features and change the knock sensor).

Older SBC motors can be made to have more power, since the cheaper and more readily available head packages, but the fuel injected computer driven motors run so well. It you are looking for a strictly track driven race motor, go old school... if you want a car that also runs good on the street, I think the LT1 or LS1 is the way to go.

 

http://videos.streetfire.net/video/B...9EF830190F.htm

http://videos.streetfire.net/video/D...D80B7B66BF.htm

[Guest 73Turbo240z]

The Opti is not that big of a deal... daily driver in the wet weather' date=' or one who washes the motor when it's hot and you are at risk, otherwise don't worry about it. I have one that I am running in my 280Z right now that has 140K miles on it (it is the vented version) You can buy the 95-97 front cover, opti and hoses to convert the older non vented Opti. You will need the cam with the longer dowel pin too, The issue is that both motors have the iron heads. Take the one with the computer and the harness. If the harness is 94 or newer, it has a flash prom and LT1-edit or Tunercat work well.... no pulling and burning chips. You can buy aluminum heads for ~200 - 250.00 and use them for a core and check out http://www.advancedinduction.com/AiHome.htm for heads and cams. Go with long tubes for the power. Get larger injectors , a larger Throttle body, CompR lifters and 1.6 roller rockers.

For a quick and easy deal on the wiring harness, call Dana at LT1350.com and have him set the harness up for you. (it's been argued that it can be done cheaper with alot of time, doing it yourself... to each his own, but I felt that my time was better spent doing other things.

I personally prefer the 6 speed manual tranny, but bolt on a built turbo-350 tranny with a big stall, throw some nitrous in it and hang on. The 4L60E transmissions have alot of issues with Big stall converters and OBDI computers. Those problems go away with the OBDII computers, but the OBDII tuning software is alot more expensive. (yes you can run OBDII computers on the OBDI harnesses and visa versa... you have to edit out some of the features and change the knock sensor).

Older SBC motors can be made to have more power, since the cheaper and more readily available head packages, but the fuel injected computer driven motors run so well. It you are looking for a strictly track driven race motor, go old school... if you want a car that also runs good on the street, I think the LT1 or LS1 is the way to go.

 

http://videos.streetfire.net/video/B...9EF830190F.htm

http://videos.streetfire.net/video/D...D80B7B66BF.htm

 

For what all you just listed, was this the build of your own car in relation to the video links you posted, cause that thing was flying...

[wheelman]

I swapped in one of those iron head LT1s and love it.

The iron heads actually flow better than the aluminum ones.

Mine came from a 1995 Caprice cop car. If you can, get a 95 or later. They have the vented opti and can be flash programmed without removing a chip.

I mated it to a World Class T5 and used a light flywheel from a late model 305 that has the correct external balancing. The motor revs in a heart beat and has tons of torque.

I put an LT4 hot cam with high rev springs in it and it pulls hard to 6000 rpm, although it gets there so fast it's really hard to tell where the power starts to drop off. One of these days I'll put it on a dyno to finish tuning and see what it really can do.

The biggest thing I ran into with the swap was figuring out how to run the alternator and get rid of the PS pump and AC.

I modified my own harness, yes it takes a while but I know every wire in it and can trouble shoot it myself.

Fuel pressure required for the LT1 is 43 PSI. I welded a sump to my stock 240 tank to add baffles but will replace the tank with one from an LS1 camaro very soon. To much rust and the fuel lines coming out the back of the tank bother me.

Longtube headers are very hard to find that will fit correctly and not present ground clearance problems. I'm running Headman TightTubes and like them OK. I've burned a couple plug wires though as the headers are very close to the block so it's hard to keep the wires from touching them.

 

As for MSnS, I've seen message threads on MSEFI.COM from a couple guys who have LT1s running with custom code. They were even able to decode the optispark timing wheel which then gives crank and cam position. I've thought about trying it myself but it's running now so I'll use my MS on a different car.

 

Wheelman

[LS1 240Z]

its been done before.. a guy got LT1 heads and intake and had them machined (think was around $500 for it to be machined) to be adapted to a regular gen one block. then used the TPI computer harness to get his spark and fuel injection

[jbc3]

I have suprised alot of people with my car My build was a little different.... but not much. I have stock ported aluminum heads, a medium cam, roller rockers, 58mm TB and long tubes. The motor was done years ago, before alot of these guys who are selling head/cam kits. They have made it alot easier and cheaper and taken alot of the guess work out of a build.

There is actually a guy in Virginia that is taking high performance high flow old school SBC heads and converting them to the reverse flow LT1 design, but I believe they are around 5K! There is alot of welding and machine work to make that happen.

Call some of the guys doing motor packages and take advantage of their knowledge.

 

Jody

[Michael]

In my opinion the whole point of a V8 hybrid is to build a stout engine from a bare-block, with good aftermarket components, custom machining, component matching and porting. The Z becomes a carrying case for the engine. If the engine moves a 3700 lb muscle, it should really move a 2600 lb Z.

 

Use the skills and philosophy that you've developed in your L6 builds - except that now you would have >2X the displacement! A junkyard engine with a swap-meet intake manifold may turn out to be a disappointment, compared to your turbo L6.

[Guest 73LT1Z]

I'll chime in here since I was faced with this choice recently with my Supra swap.

 

I like the LT1- I have a base F-body '95 block tweaked to LT4 specs along with heads/hotcam/intake/rear turbo in my TA, and it put down 498/579 with minimal tuning.

 

I took the stock motor & T56 from that car, added some proted heads, a hotcam, and ported TB and put it into the 280. I'm not driving it yet due to some bugs and limited time.

 

Naturally, when I looked at doing the Supra, I priced complete setups (LT1/T56) like Bart suggested. I found a combo here in FL for $1700! Fortunately, before I bought it, I noticed the Supra's tunnel was smaller than the Z, and the T56 wouldn't fit.

 

Along the way I had joined some Gen 3 (LSX) websites and was reading up on the newer motors. I can say that they are significant improvements over the LT1, and the smaller truck motors (4.8 & 5.3) are a steal. I bought a 2003 5.3L (325 CID) Avalanche motor from LKQ here in Florida for $400. They will ship from yard-to-yard for free. The motor had the intake and a damaged harness on it. I paid $30 for a 145A alternator, $40 for a starter, and found the rest of the accessories/brackets for under $100 elsewhere. This motor made more HP than the LT1 when new in my TA. Upgrades are not too expensive, and a H/C/I package would set you back say 1800 at most for the parts and give you 425-450 HP NA. The expensive motors are the LS1 and LQ4/LQ9 6.0L truck motor, but even they can be had fairly cheap if you shop. If money was not a factor, I'd pick up an all forged 6.0 stroker & build it up for 600 HP NA- this was done in Chevy High Performance.

 

There are numerous changes from the LT1 to the Gen 3 as far as mounting and electronics, but in your situation or if I was doing another Z, I would go with a Gen 3.