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1993 Firebird Formula "High Performance Package" Modifications
Jump to New Engine Setup Jump to LT-4 Conversion Article from CHP Magazine
Return to my Home PageRebuilt 355 LT1 Motor with...
Forged steel Crank, Rods, Pistons (for Nitrous) bottom end
ARP Studs,
New GM LT4 Conversion Package with heads, Hotcam,
Intake (ported form 58mm TB), 1.6 RRs and the go together goodies,
Edel 58MM Throttle Body, edel shorty headers
Used Hooker Long Tube Coated Headers
New Mufflex Y Pipe utilizing the Flowmaster 3-4" Y Pipe
Mufflex 4" Mandrel Bent Pipe to
4" In Spintech Muffler with dual 3" outs
BMR Lower Control Arms
CE Subframe Connectors
Polyurethane Bushings and new endlinks for sway bar
36# Accel Injectors will be seeing action again
Accel 375+ Ignition Regulator for win switch, retard, etc.
NOS Goodies - blanket and heater this year!
More Nitrous??? Gotta have it. Maybe new jets?
The engine is built for it, but I lack the fuel and drivetrain additions needed
at this point and money is tight so I will take it easy on this - yeah right! ;-)
Pre 2K1: Stock Motor (350 (5.7L) LT-1) with ("Bolt - On Mods")...
K&N Cold Air Intake with Cone Filter, Hypertech air charger, !Cat Converter, Flex (Pipe inside cat), Race readies (bypass Muffler) exhaust dump, Dynomax Muffler, 150 hp shot NOS Nitrous Oxide Dry kit, with Remote Bottle Opener, and button, knock sensor bypass switch, Heating pad with extension cord into power inverter to warm bottle, 3.73 GM ring & pinion gears, SLP (~800rpm Higher Stall) Torque Converter (Launch is @ 2700 rpm), Manual Secondary Cooling Fan Switch, T-Body Coolant Bypass Mod, TPIS Adjustible Fuel Regulator and gauge, 24# SVO Fuel Injectors, Accel 300+ digital multispark ignition and high output coil, TPIS Plug Wires, Champion 2 degree colder spark plugs with .010 smaller gap for complete NOS burn, Two extra stock rims with BFG drag radials for the track and Firestone SZ50s for daily drivers, Intellitronix Digital Gauges for Fuel Pressure and air / fuel mix on pod mounted on the A-Pillar, Added "racing"(Very lightweight) fog lights At track: Take out the spare, jack, rear panel, removed nose panel under air filter and blocked hole next to it.
Year 2000 Changes:
Castrol Syntec Synthetic Oil, Mobil 1 Synthetic Rearend Lube with posi additive, B&M Trick Shift in Tranny, rotated tires, hypertech 160 powerstat and 1 bottle RedLine Water Wetter with 15% coolant and demineralized water, EPROM changes ( Removed Rev limits in ecm, set to 6K on Acell ignition ), POR 20 paint (silver) on exhaust system, axle/reardend and black on other underside parts, TCI Cast Aluminum Tranny Pan for added cooling and easier fluid changing - contains 2 extra qts of fluid, B&M Tranny cooler - I installed this on the passenger side in front of the radiator. I got the thin version to be sure it would fit easy.
Year 2001 Changes: (40K miles on it)
Checked and changed all spark plugs with same type - champion 2 degree colder - same gap .040 They all showed signs of richness (black soot on edges) and some had oil on the threads - so I'm probably burning some oil
Bought the Tunercat software to be able to make changes to the ecm easier. So far, I've changed the fan temps and moved the injector constant up from 24.1 to 24.3 and hit my alltime best et.
To Do: Will change oil with same, rotate tires, ck for source of oil leaks (noticed when changing plugs), install new brake pads.
5/99
Installed the 4 Firestone SZ50's. Love em! Also have the BFG drag radials mounted & balanced on rims. TTS Data Master software STILL Doesn't exist, so I bought the Diacom and picked up a cheap laptop online at auction. I will connect my laptop to the car's computer. I will also install a pipe inside my hollow cat to create better flow.6/99 I installed a piece of flex pipe from a local auto place in the cat converter. It took all of 10 minutes to do and it sounds GREAT now. I'm sure it helped the flow as well. The air won't be bouncing around the empty cat anymore.
6/99 I also managed to get the Diacom software running on my new laptop. The standard diacom program will save enough data to let me hit the space bar and within one second hit it and go and have plenty of ticks left to record my 13 second runs. I have been using this in conjunction with the GTech Pro I picked up. The G Tech lets me test the car out on the street since it tells me when I have reached the 1/4 mile and I can decelerate. Using these tools, I have adjusted my TV cable to my tranny to help the car adjust to shifting with the new gears. I have also realized that it runs better in Drive or ("3") position instead of overdrive or "D" position when running the 1/4. It doesnt feel like its shifting into 4th now. I think that is where I was getting the deceleration in what I thought was third gear before. I am still running more tests with the diacom and learning more all the time. For instance - I've realized that my #2 fans is NEVER going on - atleast the ECM is not telling it to go on. I will either program it to go on or hook a switch to kick it on in between runs to cool it down. I love these new SZ-50s. They are great on dry and in rain. little tire spin.
Best G-Tech Pro run so far: 13.16 @ 112 mph - SZ50 Tires at full 35 #s pressure all around.
8/5/99 I've been having problems with cooling, so I drained and flushed the coolant and refilled her. I installed a switch and a diode so that I can control the secondary fan from the driver seat without disabling the ecm's control. It appears that my injectors are "locking up" under the NOS, so I ordered new 24# SVO injectors to replace my stock 22# 'rs. I also purchased an SLP torque converter which should raise my stall speed to more like 24-2500 rpm and help my et's. I will be installing these this week. Then, I'll take another test on the G-Tech, and then on to the Track. I also picked up a digital fuel pressure guage and LED fuel/air ratio guage with a dual pod A pillar mount from SUMMIT Racing.com. I'm hoping that these will aid in keeping an eye on proper fuel pressure on NOS and a warning against LEAN conditions. I decided to go with the digital because the analog would probably be hard to read on an electronic guage from 15-100 pounds. I also like the idea of a simple Green/yellow/red light series for lean/rich conditions. I hope that this will catch my eye better than a guage metered guage might. I'll post pictures and tests when I get them mounted.
8/20/99 Got my fuel pressure guage installed. I have yet to compare it with my original guage for accuracy. It seems to be working fine. I also linked up my fuel/air mixture sensor lead to my O2 sensor on the driver side manifold. I have not yet take the car for adrive long enough to see how it works yet. I had my mechanic install the new injectors and I tried to engage my NOS but found that my WOT switch shit the bed and I'll have to bypass it until I can get another one.
8/20/99 I finally got around to doing the cheap mod, "Throttle Body Coolant Bypass". Instead of trying to get the passenger side of the throttle body hose, I just rerouted it and plugged it. I bought a 8" hose and spliced it onto the driver side hose and ran it to the orignal upper connector. This mod keeps coolant from flowing into the throttle body. This is supposed to cool down the intake air, creating a few more ponies. I have seen other people's dyno tests of this mod yeilding an extra 6 - 8 hp. It was easy to do when I realized that I didn't have to get the hose off of the passenger side throttle body. I have included two pictures showing this mod with the two hoses capped off and the re-routing of the new hose in link above.
9/1/99 Fixed the WOT switch for the NOS. With BFG Drag radials, I shot the NOS out of the hole for an all time best so far of
12.337 @ 115.41 @ LVD on 9/1/99.
12.22 @ 112 @ LVD on 9/25/99 with a headwind
12.062 @ 114.67 @ LVD on 10/9/99 with headwind again
Winter Mods/Updates:
1. I needed better diagnostic info, so I purchased the cdrom version of popular mechanics (alldata.com) for my car. It works great. it is what my mechanic uses and it only cost like \$30. Along with the haynes manual, I can get good info now. Technical service bulletins are a big plus.
2. I now have to go to work on the rev-limiter and the adjustibility of other factors via the ecm. To this end, I bought a power programmer, and eprom eraser, and will get a IDC50M connector and an extra memcal. I would eventually like to have a couple different mem-cals so that I could run different fuel/timing for NOS/engine only. It would also be nice to try a few different things on one night at the track instead of waiting for the next week. Although I could always experiment a bit on the street. I have been exploring the diy-efi, and gmecm mailing list archives to help with my questions. I would eventually like to come up with a method to changing programs on the fly. I know there are other computer systems you can buy to do this, but Im wondering what I can do without having to buy a completely different system.
1/24/2K Bought the eraser and programmer for eproms, trying to find the idc50m to adapt it to memcals, and then get an extra memcal to start programming the rev-limits and torque converter lockup points at wot. I also picked up the popular mechanics program for my car for more info.
4/1/00 Busy Day. Rotated tires, installed new synthetic (castrol syntec) motor oil 10w-30 and new PF-25 acdelco filter, removed the rearend fluid, cleared a few specs from magnet area (looked really good though), reinstalled cover with new gasket, and installed 1.5qts of synthetic (mobil1) gear oil with one tube of posi additive too. closed it all up, and painted entire rear axle, and exhaust system as well as antisway bar, etc in POR15 silver. (Heat resistant paint that allows you to paint over the rust and lock it out from increasing). Track opened up today, but I was busy working on the car.
4/29/00 Installed my new TCI cast alum tranny pan and replaced the lost fluid with B&M Trick Shift fluid. After this mixes a bit with the existing fluid in the torque converter, I may dump some more of the mix and add more straight B&M. Its blue in color - definately not ordinary tranny fluid. I also painted my entire exhaust system with POR 20 heat resistant paint (silver). Looks real nice, and until the day comes when I chuck everything and modify the whole thing, it should help keep it from rusting. I removed my AIR pump completely saving about 5#s in weight, to make up for the extra 5#s I get from the new tranny pan with 2 extra qts of fluid. I wasnt using the pump anyways. I capped off the exhaust end with a cap I had left over from the time I did the coolant bypass. It looks much better like this too. I changed the oil and filter as usual BUT I installed Castrol Syntec Full synthetic oil instead of the old quakerstate fluid this time. I think I'm going to keep her synthetic. The tranny fluid was too hard to get, so I decided to get the B&M Trick shift instead. It is supposed to keep it cooler and make it work faster too. We'll see. I bought a tranny temp gauge but I cant install it until I setup a manifold or other contraption. I might just install a B&M cooler at the same time.
5/2/00 Finally got my new BNXF chip programmed to eliminate the rev limiter in all 3 gears at WOT, setting them to A2 (from A8 stock). To help protect the motor, I set my accel 300+ ignition to limit at 6000. I used Roger Heflin's "Promdump.exe" program to figure out the correct checksum for the chip. Chip seems to be working.
5/7/00 Discovered that the bolts on the new tranny pan were coming loose and I lost one bolt. Doh! I guess you have to crank on those a lot harder than people claimed. I pulled one bolt and will pick up a couple more tomorrow at a hardware store. I also found that the POR 15 paint was peeling off from my Y pipe. So, I rubbed it down with wool and painted it with one coat again. I will let it set and put another coat on tomorrow. Hopefully that will stick longer. I also reassembled my bottle valve handle since it fell off at the track. Today, I did some work on the Nova too - installing a new carb and an MSD 6a ignition.
5/8/00 Put the second coat of POR 20 on the Y pipe. Bought a couple of 8.8 mm bolts for the tranny pan, and installed one.
5/26/00 Went to Shako to get parts to install the nitrous gauge inline with the bottle opener/closer so I didnt have to change them when I go to the track. We ended up putting a different fitting into the opener which lays on the floor, and a 2 foot or so hose that connects it to the gauge which connects to the tank. Now I have the benefits of always knowing the pressure, and ofcourse being able to turn on/off the bottle anytime
5/31/00 Tested this nitrous setup at the track. Worked great. All-time best ET.
5/2/01 First Wednesday night of the season - hit my all-time best ET with a hot day, full tank of gas and other assorted extra weight, wheel hop because I had the tires too low in pressure... Maybe I can hit the 11s THIS year - Hit a 12.005 @ 115. Had a great time racing, meeting new people and feeling the rush again. Only bad news - my old nitrous supplier disappeared, so I may be paying top dollar for it again.
6/2001 Motor busts as I burn a hole through piston #8... Now comes the rebuild... The engine is out, and the block is in the machine shop. New GM performance parts are in, and more parts are on the way for the final install (like injectors and headers)
After the engine break in comes Lil' Demon II - "The birth of an LT-4."
Plans for new setup:
New LT4 heads, New LT4 manifold (ported to New edelbrock 58mm Throttlebody),
GM's "HotCam", Chevy stamped 1.6 rockers
Forged steel Crank, New 3D Plus Blue Cat Rods (to handle 700hp), and forged Pistons (to handle nitrous),
Accel 36# Pintle Injectors to better handle the 400-410hp engine with high pressure nitrous (+150 jetting)
Edelbrock shorty headers & Y pipe to 3" pipe, to stock exhaust to cutout and dynomax in back still
Sub frame connectors, drag launch springs (if needed)
Beef up my 700R4 tranny and install some type of delay/window switch system (mallory)
Adjust the govenour springs so that the shift points are higher. It used to shift at around 6000 under nitrous before.
I will raise the rev-limiter on the ignition box to 6500.
I will also re-program the computer to handle the new pieces better. (Using my "C.A.T.S. Engine Tuner" software)
This setup is based mainly on an article in Chevy High Performance Magazine where an LT1 engine was treated to lt4 heads, hotcam, rockers and long tube headers, and 52mm throttle body. Engine had no accessories attached or mufflers/cats. This new setup can handle much higher revs and gave 429hp at around 6100 and 425hp at 6400 with plenty of torque along the way.
Chevy High Performance Article page 1 page 2 page 3
I am compromising on the headers for driveability(and \$$$ (so I can afford a new forged crank instead) - going instead with 1 5/8" shorty edelbrock headers & y pipe. SLPs flow better, yes, they also cost twice as much, and I couldn't see the need for that extra 5 hp or so unless I was going to replace my whole system which (for now) I decided NOT to do. So, with my exhaust restriction but bigger intake, I will probably be a bit off the numbers of CHP, but I'm aiming for around 400+hp to put me in the low 12 second range on engine. Along with some suspension mod's to help prevent wheel hop and plant my tires better, I hope to do this consistently. I'm hoping to get 410hp NA, 560 with the juice. Maybe I can hit low 11s on juice! - (before I get kicked out for not having a cage)
To get back on my "juice habit" I will be illegal at the track, probably putting me into the low 11s with the 150 shot (not out of the whole anymore).
So, I wont run the juice at the track the way I used to (don't want a roll cage in this car), but I will have to do it a couple times just to see how it does.
The bottle will be mostly for street fighting, and street drags. Just like in the movie, Fast & Furious, once you feel the power of juice pushing you ahead of an opponent beside you, its a rush you can't give up. I'm hooked on an expensive habit. It may also help me compensate for any low end sluggishness I may see with this bigger cam. We'll see...
This is a "mild" setup - trying to maintain my ability to have a calm everyday driver and still be able to compete in the "Street Series" at the local track (where you can't run under 12 flat in the 1/4 for this class) and maintain my "streetability" with no roll cage..
From what I've heard about this type of setup - it is very calm in partial throttle situations and doesn't really get the power coming in until upper mid range rpm's kick in which should be fine with my fairly slippery SLP torque converter. If its too sluggish, I may need to trade up to a higher stall vigilante converter.
7/3/01 Engine block gets bored out to 355 - yes one month later. :-( Engine builder has found parts, and I HOPE it will be ready in a couple weeks.
7/25/01 My "new" engine is done! I took this picture of the empty carcass awaiting its new energy source as I installed the newly modified ecm programmed chip. The new engine was still in the shrink wrap sitting in the back of their van. I modified the rpm cutouts, fans temps, injector rate, cylinder volume, and target idles for park and drive. I created a second bin(B) that was the same, but kept the stock idle values and changed the injector rate from 36.4 to 36.1.
8/1/01 Engine gets installed. I drive it home with open headers and look for pipe. I finally find that a 3" pipe from autozone fit right into the headers and a 3-2.5" reducer fit inside my stock pipe. I got two clamps, and it works.
8/7/01 Fixing the shift points:
Three was the charm when I was lucky enough to get my car into my "next door"
tranny shop by pulling some strings.
I tried changing these govenour springs/wts last night, and realized it was
impossible without dropping the tranny - something I didnt have the lift or room
to do with car on a couple jackstands in the driveway.
My car was shifting at 5100 since my engine swap if you recall...
They moved my TV cable basically all the way "in" since my 58mm throttle body
seems to have a larger diameter "turn" then my stocker did. This got me shifting
almost 5300. Then they tried two weights changed, and it wanted to shift
somewhere in the ozone and I had to back off at 6375 before I blew something
up. Then they tried one stock weight, and the 2nd lightest weight (playing
conservative which got me back to normal - around 5750, then we went with the
lightest weight along with the stock weight. I got it to 6175.
Although I've heard different claims of the LT4's redline from 6300 to 6500, I'm
aiming for 6200 shift in 1-2. I will try to
test it out at the track tomorrow.
Hopefully this wont be TOO light for when I add nitrous. This USED to push me up
about 200rpm. No juice for a few weeks. Only 93. Ofcourse, I could leave it and
program the juice to turn off before it pushes the limits of the springs. For
now, I programmed a rev limit of 6300 back into my chip for safety (as well as
raising the idle and lowering fans) but I'll have to trash that if I add juice
up there.
8/29/01 Testing out different programs... After a few weeks at
the track, and scrounging the internet for help on re-programming my new setup,
I created two separate programs - one for nitrous and one engine. I got 12.9s
on engine and 11.91s on nitrous this last week. With this came my first ever
"11 second run" yahoo! I still have problems occuring in both
situations though - getting knock retard both on engine as well as on nitrous,
and having the injectors shut off at high rev (6375 highest recorded) which
produced a very lean ( and dangerous ) condition under the nitrous. I'm not
sure why this happened since I programmed the fuel shut off to be much higher.
After Further Review - the play stands as called. I must have injector lockup.
I ended up pulling an 11.626 before the end of the year BUT, I'll have to return
the larger injectors this next year (2002) so that I dont run out of fuel, and
I may also need a larger in tank pump so I dont run out of fuel.
2002-03 Sorry - no updates on the changes done during 2002 and 2003 seasons
- too busy
2004 - Seeing problems with hesitations as I ease into her from stops. I have tried removing the 3 stage retard, and the acell ignition but it still is giving problems and I noticed it popping in the exhaust without the ignition hooked up. I'm trying to adjust the programming now. I'm also going to test the coil. When I get her running smoothly again, I'll get her racing.
