[VASTREETRACER]

My 14 year old daughter and I are about to start on her first car. Its a 1998 V6 firebird thats about to get gutted and completely rebuilt getting a gen v lt1, I haven't decided on a trans yet but she wants a manual, probably a 12 bolt rear, and all upgraded suspension. Im on the fence as to if I want to keep it direct inject or convert it to port injection. My question is what are the pros and cons of converting it over vs keeping it? I and leaning towards holley for the fuel injection and engine controls vs a stock ecu. And before anyone says it, i was going to go LS3 but ran into a deal for this LT1 I couldn't pass up.

Thanks in advance
Mark

[bishopts]

Direct injection gives you better atomization,
you can run higher cylinder pressure without worrying about pre detonation,
typically all direct injection engines since the early 2000s make similar power but use less fuel to make it,
It responds to E85 better than low pressure fuel systems
Its already built for it so you wouldn't have to re engineer the heads and fuel system

[AZIROC]

Here i thought you first ment a LT1 from the 93-97 years and I was ready to scream....noooooo!

While im sure its possible... lt1/lt4 swaps are just starting to be done so not alot of info about what's all needed. But it is possible. also know 98 is 1 of those "wierd" 1 year only cars on alot of parts. But can swap them over to 99-02 stuff


You would prob be better off with a 8.8 or 9 inch but a 12 bolt will work as well. Just realize ur talking 4k minimum for a rear end.

While starting off with just a shell is best, imo, unless that LT1 is special, your best (least headache) route would be sell the v6, get a 99-02 v8 and ls3 swap it (keeps factory harness...just need fuel injector and knock sensor extensions). i I know, doesnt answer your fuel question but all that is going to be ALOT of work vs doing an engine swap...which im about to start in my wifes 99 ws6.

[bishopts]

Honestly the gen 2 Lt1 has potential. They are cheap, they can easily make power and to get around the optispark is so easy. On my 96 trans am i swapped to an LS1 pcm and eliminated the opti for around $200. I actually learned a whole lot about how pcms actually do things and also how closely related the vortech 350 and the LT1 were.
But in this instance, it would be much cheaper to do like I'm doing with my daughter and buy a LS1 car.
I got my 99 SS for $5500 and it runs and drives.

[AZIROC]

[QUOTE=bishopts;11514729]Honestly the gen 2 Lt1 has potential. They are cheap, they can easily make power and to get around the optispark is so easy. On my 96 trans am i swapped to an LS1 pcm and eliminated the opti for around $200. I actually learned a whole lot about how pcms actually do things and also how closely related the vortech 350 and the LT1 were.
But in this instance, it would be much cheaper to do like I'm doing with my daughter and buy a LS1 car.
I got my 99 SS for $5500 and it runs and drives.[/QUOTE


Speaking of PCM. I have a 86 iroc with a 406 and ha e always had tune issues since its OBD1. come to find after all these years is something like the 00-02 chevy astro vans had a vortec 350 (with a distributor)...but it was OBD2. Grab that harness and adaptors and it (in theory) should work. But ill have to learn tuning between that and the wifes ls3 swap.

[bishopts]

so the early v8s were 4x crank count. so thats 4x crank 1x cam. the reference was pretty much : crank yes cam no or crank yes cam yes. it was bank fire injection so left bank injection right bank injection.
vortec 350 has a spider injection system with a distributor, if you took off the spider injection intake and put on a LT1 intake then used the same wires that were in the spider injection to power the common rail LT1 injectors, it would work except the intake will not support the distributor hole. the big difference was the crank reference. optispark used a 360x count from the optispark where vortec 350 used a 4x from a crank sensor. 96-97 LT1 had a crank sensor in the same place as the vortec 350 but it was not for crank reference it was for knock detection.
fast forward to LS1 they used a 24x crank 1x cam. BUT they used a 0411 pcm that the vortec 350 used also. they also went to sequential fuel injection.
so for 96-97 LT1 its as simple as repin the existing harness to a 0411 pcm out of a express van and using hp tuners to tell it that its now a vortec 350 with a\c pressure switches instead of pressure transistors. it will use the crank sensor as a crank reference and the optispark will be a distributor\cam reference. and if you wanted to make it even more reliable you can get a 24x trigger wheel that replaces the 4x so you can make it coil near plug ignition like an LS1.
Elliots Portworks is actually like 10 mins from my house. he does a lot of gen 2 LT1 work with the heads and cam combo. so its possible to make those reliable and powerful.

[bishopts]

to go from 98 v6 to gen 5 LT1 the engine and the car are going to be on two different plains.
the coolant gauge will need the sensor from the 3.8. the fuel gauge will be from the tank to the cluster, the speedo will depend on the choice of transmission. the tach will require an adapter to modify the signal from what it was to what it needs to see.

remember on the transmission choice, the stock setup has a torque arm. T56 magnum F will have the provisions for a torque arm to bolt to it. UMI and BMR have torque arm mounts to isolate the torque arm from the transmission and allow you to use non F body transmissions.

[VASTREETRACER]

Thanks for the replies. I know its going to be a long and expensive project for my daughter and I but it will be a great learning experience for the both of us. Ive built several 4th gens and a 5th gen some im familiar with the LS platform. I currently have a 2017 Camaro SS I've fone a few things to. My biggest concerns are going to be getting the gauges to work with it which im told is doable or I can do the holley tablet, which to me doesn't give a clean look, and I like a factory, clean look. Ive been pricing a lot of parts out and well ill probably be somewhere in the 30k+ range before its all said and done, which is beyond stupid but, the experience of building my daughters first car with her makes that dollar amount not really relevant... to an extent lol

[bishopts]

if you stay with your stock gauges my previous post answers that.

if you go with a t56 magnum F then the speed sensor for the v8 cars will work. if you can get a cluster from a v8 car then the tach will need to go from 24x to 52x, think the speedo go to a higher number on the v8 cars, 120 for v6 and 150 for v8

[bishopts]

Turbo 3800 series 2 would be awesome. Just wanted to say that.

[beowulf556]

With the amount of time and money spent putting an lt1 in a 4th gen you might as well buy a 6th gen. It’s superior in every way. Find one with a blown engine and build a new one with your daughter.

Buttttt if you still go for it you absolutely need to make a video series on it!

[VASTREETRACER]

I have a 6th gen and offered to get her one but she wanted a t top ws6 or firehawk... she actually wanted a TTop Iroc but I couldnt find one that wasnt rusted completely through or that someone didn't want a fortune for. I found this V6 98 for cheap, its a solid car and she fell in love with it the second she saw me unloading it. She does want to create a YouTube channel, like any 14 year old would which is fine. We started pulling stuff apart this weekend pulling the interior out. Next weekend will probably be the engine and trans.

Originally Posted by beowulf556

With the amount of time and money spent putting an lt1 in a 4th gen you might as well buy a 6th gen. It’s superior in every way. Find one with a blown engine and build a new one with your daughter.

Buttttt if you still go for it you absolutely need to make a video series on it!

[jlaudio11]

Chris Johnsen or Chris1313 Racing Inc just went 8's with a sbe lt1 in a 4th gen formula. His car is a light race car but he documented and posted the whole thing on facebook. Thats where I would suggest starting. He modified original ls headers with flanges to fit the lt etc.
I wanted to do this swap on the 94 i have when the gen 2 lt1 took a crap but mating to the lt t56 and everything else didn't seem like the smartest money investment etc

[2023-SS]

why not a 90's 4th Gen LT4? the LT1 in the ~1993 camaro was 275, the LT4 corvette had a "hot LT4 cam" available that should be mid 300 HP?

and basically plug & play in a 3rd gen?

and a 700R4 is the MOST FUN in the world, digging hard out of the hole & barking second in an automatic, esp if you get the dual gate manual shifter