stroked LT1 with hotcam, computer question
09-10-2005, 01:20 AM
#1
stroked LT1 with hotcam, computer question I've built a 381 cu in LT1, .020 over srp piston, -16cc dish, 3.75 stroke eagle crank and 6" eagle rods. I've also installed the LT4 hot cam with 1.6 ratio rockers.
will the stock unmodified computer be able to run then engine at least to drive normally and not have any problems? will the mass air see the increased air flow and adjust fuel properly? its is a 1995 pcm.
thanks
will the stock unmodified computer be able to run then engine at least to drive normally and not have any problems? will the mass air see the increased air flow and adjust fuel properly? its is a 1995 pcm.
thanks
09-10-2005, 01:43 PM
#3
Wow you needed to start asking questions a lot sooner. A stock engine can benifit greatly from pcm work which for your 95 is as cheap as $50 for professional tuning. Here you have all that money in a stroker with a poor cam choice and expect it to run right. If stock injectors in it yet I might run it enough to move it around the driveway but that is all. You will need larger injectors to properly feed that engine and that is another thing that 100% requires immediate programming or engine damage is likely. If the heads are untouched expect to be greatly disappointed in all your effort to this point.
Now I am not picking on you here you are not the first to do this sort of thing nor will you be the last.
I find it amazing how people can put all this money into cars without doing the pcm, think of it this way not reprogramming the pcm is exactly like not rejetting a carb and resetting timing on a carbed engine, does that make it sound like as bad an idea as it really is?
Again you can have true custom professional tuning for under $100, peanuts compared to what it will cost you if the tuning is wrong enough to damage the engine.
Now I am not picking on you here you are not the first to do this sort of thing nor will you be the last.
I find it amazing how people can put all this money into cars without doing the pcm, think of it this way not reprogramming the pcm is exactly like not rejetting a carb and resetting timing on a carbed engine, does that make it sound like as bad an idea as it really is?
Again you can have true custom professional tuning for under $100, peanuts compared to what it will cost you if the tuning is wrong enough to damage the engine.
09-11-2005, 12:59 AM
#4
ive got a hotcam in my 396. i say get at least a base tune to help with the air and fuel. you can take your pcm to most shops and they will be able to do this for you. i picked up a good bit of power with a dyno wide band tune, its worth the money.
09-11-2005, 05:41 PM
#6
the reasons I ask are I am in the middle of buying a house right now and my funds are STREEEEAATCHED way out. I'm selling the current engine in my pickup (2001 Vortec 6.0L) and need a replacement quick. I will be going megasquirt with the LT1 and bigger injectors very soon. I didn't want a big cam right away. i will probably be selling the LT1 in the spring to finish my EFI big block & blower going in my pickup. i'll leave the cam to someone else to choose when i sell it.
the heads are stock castings, with seats cut to 2" intake 1.56" exhaust. Had some porting done by a local speed shop.
Ferra valves, LT4 springs, and comp full roller steel 1.6 rockers.
thanks for the reply's.
the heads are stock castings, with seats cut to 2" intake 1.56" exhaust. Had some porting done by a local speed shop.
Ferra valves, LT4 springs, and comp full roller steel 1.6 rockers.
thanks for the reply's.
09-12-2005, 01:29 PM
#7
Your cars going to be fucken slow with a hotcam. I mean comone, you should have rebuilt your motor and just did a head and cam. Your miss matching parts and its not going to come out to be fast. I beat it barly breaks high 12s with that cam.
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09-12-2005, 05:54 PM
#8
LT4 springs are maginal with the LT4s lightweight valves I don't see them controlling larger valves well atall. The ability of a stroker to keep revs down as compared to a 350 with the same cam might let them work for a littlewhile.
If the car is setup where it is possible to run a stock pcm why are you looking to go megasquirt on the LT1? The LT1 pcm does a pretty damn good job just so long as you stay below 7000rpms which you will be.. With these sorts of projects going on I bet you have some spare parts laying around, tell us what you have and maybe there are a few small items one of us could use to allow you to raise the funds for a tune, I think Madz28.com and pcmforless.com start at about $50-60 plus shipping for a one time tune, with unlimited updates available for a little more money.
If the car is setup where it is possible to run a stock pcm why are you looking to go megasquirt on the LT1? The LT1 pcm does a pretty damn good job just so long as you stay below 7000rpms which you will be.. With these sorts of projects going on I bet you have some spare parts laying around, tell us what you have and maybe there are a few small items one of us could use to allow you to raise the funds for a tune, I think Madz28.com and pcmforless.com start at about $50-60 plus shipping for a one time tune, with unlimited updates available for a little more money.
09-12-2005, 07:37 PM
#9
all you non believers..... my 396 with stock heads made 400hp 450tq (at the wheels) with the hotcam and a base tune...... now i have full ported heads and a matching intake and by no means is it slow.
09-12-2005, 07:51 PM
#10
Originally Posted by 00Z-28-LT1
all you non believers..... my 396 with stock heads made 400hp 450tq (at the wheels) with the hotcam and a base tune...... now i have full ported heads and a matching intake and by no means is it slow.
09-12-2005, 11:33 PM
#11
i'm going to ebay harness + pcm and buy another megasquirt, go opti-less at the same time with the same DIS ignition i used on my 6.0L. i'll need the megasquirt for my blown big block later on anyways.
i've got two complete sets of injectors from a turbo coupe, should be plenty of fuel to run this motor. i researched they are aprox 35 lb @ 3 bar? megasquirt can handle them and correct for any error anyways.
should have for sale the following
1995 LT1 + 6speeed harness uncut
1995 ECM w/ knock module
1995 vented opti and
descreened MAF
i've got two complete sets of injectors from a turbo coupe, should be plenty of fuel to run this motor. i researched they are aprox 35 lb @ 3 bar? megasquirt can handle them and correct for any error anyways.
should have for sale the following
1995 LT1 + 6speeed harness uncut
1995 ECM w/ knock module
1995 vented opti and
descreened MAF
09-13-2005, 12:44 AM
#12
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I think its a cool project you got there, you could have did things differently but just do what you can with it and enjoy it. I am not sure if I read this correctly or not but is the engine in? if so how does it run with stock injectors?
09-13-2005, 12:17 PM
#14
I would never run a hot cam with a stroker motor, Think about this yeah you made 400hp plus.... But that just shows you, That more can be made with a cam thats bigger and still streetable.
09-14-2005, 06:18 PM
#17
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Originally Posted by 00Z-28-LT1
all you non believers..... my 396 with stock heads made 400hp 450tq (at the wheels) with the hotcam and a base tune...... now i have full ported heads and a matching intake and by no means is it slow.
09-15-2005, 08:26 PM
#18
those numbers are with stock heads ( they did have ferra valves and they were also cut for dual springs but thats it). now they are ported and i added a tnt 100 shot. i need to set the valves and then i will post up the new numbers as soon as it gets re-tuned. oh, a friend ported them for me at a local shop btw.
