LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

94 z28 stock lt1 to 383

Old 05-02-2019, 11:24 AM
  #31  
Registered User
Thread Starter
 
Join Date: Apr 2019
Location: Warrenville, sc
Posts: 24
Re: 94 z28 stock lt1 to 383

Originally Posted by Injuneer View Post
This guy can build a 4L60E capable of reliably handling 1,000+ HP. Prices for a 500 HP build are very reasonable, given the quality parts he uses. No need for a shift kit.... that can all be taken care of in the PCM programming.

https://cahallperformancetrans.com/4...ds-%26-pricing
Wow, I appreciate that. Basically the same price as the kit, and the work would be done for me! He looks very professional and well versed in these transmissions. I look forward to contacting him and having my transmission rebuilt by a professional of his experience.
I am going to get estimates on having my engine done, maybe someone that does heads and intake and the block all at one will give me the best deal.
But aside from transmission and engine I will still need to send off my PCM and will have to worry about my rear end, will want better rims and tires too as I can barely hold traction as it is much less doubling my HP.
I will probably end up selling my subs and amp and replace it with a cheap radio and get a stub antenna, I have an $800 stereo system in my car right now and I dont need it lol. Might remove my back seat too, remove a little weight.
I also want to get the UMI shock tower brace, torque arm, drive shaft loop, shocks and springs, and their stage 2 front end kit, as well as long tube headers and C5 brakes so I can stop this monster.
I have a lot of people recommended the same person for my heads and intake, so I will probably go along with that as I would rather it be done right than save a little money.
Might as well get a better cam as that apparently helps some too.
This will take me a while but I am eager to see it through.
doritoboy100 is offline  
Old 05-03-2019, 02:07 PM
  #32  
Registered User
 
Join Date: Apr 2004
Location: Toledo,Ohio
Posts: 393
Re: 94 z28 stock lt1 to 383

is this your first car your hopping up? wow.....i used to just put a bigger carb maybe headers at first , then i learned about what a cam and porting can do, if you can afford it .....it's a lot of what i'd do
LT4orbust is offline  
Old 05-03-2019, 02:22 PM
  #33  
Registered User
Thread Starter
 
Join Date: Apr 2019
Location: Warrenville, sc
Posts: 24
Re: 94 z28 stock lt1 to 383

Originally Posted by LT4orbust View Post
is this your first car your hopping up? wow.....i used to just put a bigger carb maybe headers at first , then i learned about what a cam and porting can do, if you can afford it .....it's a lot of what i'd do
This is my first build, yes. Stock 94 z28.
I am planning on having heads and intake done and getting a better cam, rebuilding my transmission and getting a better torque converter, and then having my PCM flash tuned. That alone should show substantial improvement over this 25 year old car. Along with bigger wheels, stronger real diff and new shocks and springs and a few other odds and ends.
I would like to stroke it at some point.
Though I do have a full LT1 engine in my carport, I might just do all the work on that one since it's already removed, and then keep this one stock.
I have received a recommendation on who to send my PCM to, my Transmission to, and my heads and intake. I am probably going to go through with this first, and continue upgrading the car itself before hand, and then when I have the spare engine all beefed up and ready to go i will just swap it and the PCM and be ready to go.
I know there is a huge list of things that have to be upgraded or repaired or changed, so I'm just trying to compile this list, get references as to who to get each part from or send each part to, and I'm planning this all around when it needs to happen and how much it will cost.
doritoboy100 is offline  
Old 05-06-2019, 02:14 PM
  #34  
Registered User
Thread Starter
 
Join Date: Apr 2019
Location: Warrenville, sc
Posts: 24
Re: 94 z28 stock lt1 to 383

Alright guys, so I'm kinda dumb and forgot that I had a spare set of lt1 heads already ported and polished in my garage. And after looking a bit I've decided I'm going to send my spare block off to a local engine shop, and have it stroked. I'm going to order the edelbrock air gap intake and BBK twin 58mm throttle body, a little under a grand for both, and I'm waiting on compcams to tell me what cam and stall I will need with that setup with the lower and rear end work I plan to do to it.
Probably $800 for the full c5 brake conversion, $2400 for the UMI drive shaft loop, torque arm, shocks and springs, and front end kit,
And I'm still trying to find out what I will need for the rear end, if anyone has any links or what they used that would be helpful. Might go the 8.8 route.
And the transmission rebuild is probably going to run me $900, and im still looking at wheels and tires, right now I'm at $1300 but I'd like to go cheaper lol.
So that's about $6500 minus the torque converter, cam, stroking the motor, bigger injectors, dyno tuning and anything else I'm missing. Oh and $500 for a new waterpump and optispark and new wires and plugs. Lol.
Hopefully I may end up under 10k for this build!
doritoboy100 is offline  
Old 05-06-2019, 02:58 PM
  #35  
Registered User
 
Join Date: Jun 2003
Posts: 866
Re: 94 z28 stock lt1 to 383

I would save the $ and not get the Edelbrock intake. Just have a stock one port matched to your heads...you will also need the throttle body opening on intake machined to accept a 58 mm TB

IMHO I would reach out to Lloyd Elliott about a cam vs Comp

Your TC choice will depend on cam and rear gears....don't cheap out on a torque converter. Any stall above 2400 get a external trans cooler

Your 58 mm TB will likely need some modification to it to get the car to idle right which requires the ability to scan for IAC counts...whole long topic on that
Chimera96 is online now  
Old 05-06-2019, 05:02 PM
  #36  
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 67,285
Re: 94 z28 stock lt1 to 383

What are the flow numbers on the ported LT1 heads? Hard to pick a cam without knowing that.

I second above comment on the Edelbrock Air-Gap intake. Offers nothing the stock intake doesn't already have, other than the red powder coat. In fact, the plenum volume has been sacrificed to create the "air gap".

58mm throttle body is really not required until you exceed 500 HP at the flywheel. My stroker made 496 HP on the engine dyno, and the shop showed me on the dyno that 52mm TB would have been able to supply all the air the engine needed. The power peaked with the 58mm TB only 77% open. Opening it further didn't change anything. They still laugh at my 58mm TB.
Injuneer is offline  
Old 05-06-2019, 05:22 PM
  #37  
Registered User
Thread Starter
 
Join Date: Apr 2019
Location: Warrenville, sc
Posts: 24
Re: 94 z28 stock lt1 to 383

Hmmm, well I dont want to have something unnecessary. If 52mm will do then I'd rather get that or something right above it in case I ever want to add more power. I want to get at least 400rwhp, so 500hp at the flywheel is where I'm going to be around. I was looking into the ss hood and ram air intake, I can send my heads and spare intake that hasnt been ported off, I'm not sure what the specs on the heads are currently, but what would I need to attain the 500hp? I will message lloyd today, and if I can zero in on that I guess he can help me with the cam and stall himself.
I was told the edelbrock would help with head reduction of the air coming in, but I do have a spare intake lying around that I can toy with. 2, in fact.
doritoboy100 is offline  
Old 05-06-2019, 08:17 PM
  #38  
Registered User
 
Join Date: Apr 2004
Location: Toledo,Ohio
Posts: 393
Re: 94 z28 stock lt1 to 383

and I thought it was a weekend car.....yup.... I am
LT4orbust is offline  
Old 05-07-2019, 12:22 AM
  #39  
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 67,285
Re: 94 z28 stock lt1 to 383

Have the heads flowed by a competent shop. You're looking for at least 280-290 CFM on the intakes, Closer to 300 CFM, the better. 195-200 CFM on the exhaust.

The throttle body bores on the stock LT1 intake manifold are 52mm. AS&M used to make a 54mm TB, not sure if they still do. The 54mm throttle body can be bolted to the stock manifold with minimal flow disruption.

REVISED TO CORRECT ERROR ON STOCK INTAKE MANIFOLD BORES

Last edited by Injuneer; 05-10-2019 at 11:50 AM.
Injuneer is offline  
Old 05-07-2019, 12:40 AM
  #40  
Registered User
Thread Starter
 
Join Date: Apr 2019
Location: Warrenville, sc
Posts: 24
Re: 94 z28 stock lt1 to 383

Originally Posted by Injuneer View Post
Have the heads flowed by a competent shop. You're looking for at least 280-290 CFM on the intakes, Closer to 300 CFM, the better. 195-200 CFM on the exhaust.

The throttle body bores on the stock LT1 intake manifold are 54mm. AS&M used to make a 54mm TB, not sure if they still do.
Everything I need to know! You're the man!
doritoboy100 is offline  
Old 05-08-2019, 04:52 PM
  #41  
Registered User
 
Join Date: Jun 2003
Posts: 866
Re: 94 z28 stock lt1 to 383

OP

Since you have a spare LT1...build it vs throwing heads/cam on your in car motor.

If your in car motor is at or more than 100k mi...you don't want to throw H/C in a motor with stock old bearings. The new power, and higher rpm's the motor will make, will be hard on worn internal engine parts (bearings, rod bolts) which can lead to engine failure sooner than later

On the TB, I agree with injuneer that a 52mm is more than enough for your goals. I would have the stock one bored to 52 vs buying a aftermarket one if you can find someone who does that. Many years ago I used David Kudos but IDK if he still does them. A stock TB bored will be WAY more plug & play than a aftermarket one. The later typically require a drill mod which in itself is not hard to do but unless you have scan software to measure IAC counts you are blind to what those readings are which need to be brought into spec with larger aftermarket or rebored TB's especially with camed motors

You now have the broad strokes on who to go to for H/C, short block rebuild and tuning.
Chimera96 is online now  
Old 05-09-2019, 01:33 AM
  #42  
Registered User
Thread Starter
 
Join Date: Apr 2019
Location: Warrenville, sc
Posts: 24
Re: 94 z28 stock lt1 to 383

Originally Posted by Chimera96 View Post
OP

Since you have a spare LT1...build it vs throwing heads/cam on your in car motor.

If your in car motor is at or more than 100k mi...you don't want to throw H/C in a motor with stock old bearings. The new power, and higher rpm's the motor will make, will be hard on worn internal engine parts (bearings, rod bolts) which can lead to engine failure sooner than later

On the TB, I agree with injuneer that a 52mm is more than enough for your goals. I would have the stock one bored to 52 vs buying a aftermarket one if you can find someone who does that. Many years ago I used David Kudos but IDK if he still does them. A stock TB bored will be WAY more plug & play than a aftermarket one. The later typically require a drill mod which in itself is not hard to do but unless you have scan software to measure IAC counts you are blind to what those readings are which need to be brought into spec with larger aftermarket or rebored TB's especially with camed motors

You now have the broad strokes on who to go to for H/C, short block rebuild and tuning.
Someone stated previously that stock TB is 54mm, which will be plenty, and I can always change that later as i wont have spent money on it. And yes I'm going to work up the spare engine as it has significant less miles than my in car engine, which is almost at 201k. I have a local engine shop that said they would do a full rebuilt and stroke it for $1300-$1500 labor, and they advised cast steel over forged iron internals for budget, and they say it can more than handle the HP I'm aiming for, please advise me as to whether I should go forged anyways, i dont intend to do anything else to it, but i may strike it rich one day and throw a power adder or something lol.
Lloyd elliot advised me on a cam and stall, and said he would fully port my intake for $200 and custom cam for $300, he specified I go with -5cc flat top pistons as well. I still need specifics on the heads I have, they were ported and polished and rebuilt and look pretty good, but if they arent getting at least 270cfm I want them to be done by lloyd.
I still dont know what size injectors I should go with, I want to get big enough that I can have it tuned and the tuner may say they are fine or they're a little much you can go down to this exactly, rather than have to completely redo the tuning because it wasnt supplying enough.
Aside from this I still have to have my transmission rebuilt, a new torque converter, c5 front brakes, rear end work and suspension work, and I will need at least 17" wheels, might go with 18 though, wider on back. I know my transmission is ****ed up already, but my wheel/tires are luckily still my weak spot. Break traction and spin tires pulling out of parking spots lol. I'm scared to get better wheels/tires and have my rear diff blow up lol.
Please let me know anything else I can do, any cheapskate ways to improve performance or any cheap part that is still sturdy and performs as well as an expensive one. Stuff like that will allow me to focus my budget on splurging for this or that.
Thanks again everyone, I've learned so much since I started this thread in the wrong category lol.
doritoboy100 is offline  
Old 05-10-2019, 10:48 AM
  #43  
Registered User
 
Join Date: Jun 2003
Posts: 866
Re: 94 z28 stock lt1 to 383

Originally Posted by doritoboy100 View Post
Someone stated previously that stock TB is 54mm, which will be plenty, l.
.ah no....the intake is already ported to 54...which is why the intake needs to be opened up if you go 58mm TB

Stock TB is 48mm

Don't get a cast stroker crank. The budget ones like Eagle are weaker than the stock cast crank...which is WAY better than a cast Eagle crank. Get a forged crank. Scat is "OK" for a decent $ if you go with their forged crank

30 lb injectors are likely good for your goals. Your tuner can advise

You are all over the map on what you want to do to the car and it will cost $, more than the car will be worth if you are not doing the installs yourself.....and even if you are the parts for all your "wants" (stroker, TB, injectors, tune, rebuilt trans, TC, gears, suspension, brakes, tires, rims) are not cheap.
Chimera96 is online now  
Old 05-10-2019, 11:48 AM
  #44  
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 67,285
Re: 94 z28 stock lt1 to 383

HOLD ON - MY MISTAKE - Stock LT1 intake manifold bores are 52mm diameter - see my photo below.

Old age (and posting while assembling IKEA furniture) is taking it's toll.


Stock throttle body = 48mm

Stock throttle body can be bored to 52mm, and fitted with larger blades.

Aftermarkets are (or were) available in 52mm, 54mm, 58mm, and "monoblade" (single oval blade, no center division).

Stock intake manifold bores = 52mm

Using a throttle body larger than 52mm requires that the bored in the intake manifold be opened up to match the throttle body bores.



Injuneer is offline  
Old 05-10-2019, 11:57 AM
  #45  
Super Moderator
 
Injuneer's Avatar
 
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 67,285
Re: 94 z28 stock lt1 to 383

Stock 48mm TB and 52mm intake manifold:




Injuneer is offline  

Thread Tools
Search this Thread
Quick Reply: 94 z28 stock lt1 to 383


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.