need help making my 1G racecar faster

[nehring8]

My car is a 91 Laser:

First off, the class that I race in is a naturally aspirated class only and it is a "stock" class so that is my boundary (dirt circle track). I have put together an engine out of "junk yard" parts that runs pretty good (came in 3rd out of 30 running with V6's, and I'm consistantly in the top 5 to 10% in my 4cyl only class). I started with a 2.4 block/pistons/crank out of a 97 galant, pushing the "stock" rule i know, (removed the balance shafts) and put my stock head/intake/throttle body/exhaust on and upgraded to a set of turbo 5 speed cams. I also use a set of 275cc injectors out of a galant. I am running the stock ECU. I run 93 octane pump gas and am getting about 210psi compression across all 4 cylinders.

Am I missing anything that would make more power that can be found easily in a junk yard?

 

[nehring8]

I remember doing a test on the voltage running to the injectors before and after changing from the 275cc to the 390cc. with the 275cc the highest voltage while reving the engine up was about 4.5V (I understand that this is really a square wave at different pulse widths, so basically my meter was giving me an average voltage) when I put in the 390's the highest reading that I could get was 2.5 volts... so the ECU must be changing the pulse width to get the right A/F ratio. I don't know if it matters but I completely kill the power to my car after each race and the ECU has never gone into open loop on me...I'm guessing that if I ever loose my O2 sensor the car will not run...I would love to work on tuning my car but have no equipment for it and since it is a track only (play) car I don't know if I will go that far, the plugs seem to look perfect so I wouldn't think it's too far off...and I'm always competetive with or beating the neon's and ecotecs which is fun

 

[ramsack]

This would be all fine and dandy using bigger injectors, or doing so with e85, ONLY if every injector injected linearly with fuel amount vs. pulse width. There is no such thing and there never will be. This is why they have to be tuned. Even putting 2g 450cc injectors on a 1g car will make it not run right. The same volume injectors, but slightly different volume vs. signal.

 

[nehring8]

Went out racing again about a week ago, this track is a 1/4 mile long straights and tight corners, it is a FWD class so v6's run there, anyway started 14th in the A feature with all of the fast cars in the front because it was point champion night, anyway I consistantly moved up the whole race (12 laps), was in 3rd with 3 laps left and two brothers to get around, I got around the 2nd place brother and was gaining on #1 going to pass on the last straight, well the brother behind me decided to bank board off of me in the last corner to try to get around me, slowing me down enough that I couldn't quite win (by about a foot) considering most of the cars out there are 3.4's and 3.8's with mid 200 hp, didn't think I did too bad

 

[Dhan]

Sounds like a good race! Back when I was living in Reno, I used to race my Mazda 323 alongside the big V6s. Despite the power difference, I never felt out of place or that I was at any real disadvantage.
Probably helped that the car weighed so little that a strong breeze was enough to blow the thing away .

Don't know if it's against regulations for you, but I had a small camera mounted where the dome light had been. Its fun to see it all over again (and to share with your friends on DSMtuners.

 

[nehring8]

I haven't put a camera in my car yet, but I had a guy behind me at a track running video and he put it on youtube. you can get a good look at a DSM running hard, this was last year and my car handles much better this year with the rear sway bar on

YouTube - Warren County Speedway in car FWD Taylor Musselman Final Night GP Main

watch the red and white car #6 starting a couple rows up and on the outside THAT'S ME

 

[nehring8]

UPDATE: I went to a 3 day race this weekend, dang there were a lot of preludes there. did OK the first night but didn't qualify because someone decided to use me as a bankboard to get around me in a corner. the second night I qualified by passing 5 cars in my race (I was the highest qualifier for the night) then ran a dash for cash and got 2nd by half a car length. Sunday was the big race, drew 10th starting position, moved up to 7th in a few laps and was gaining on the front of the pack, got tapped in the right rear and the car got real squirrley, made a couple more laps and decided to pull in because it didn't feel safe, had a flat tire and a severely bent rim. oh well that's racing (the fastest car does not always win). I really enjoyed passing the HONDA's

 

[nehring8]

UPDATE: Ended the season with a WIN at a very big race, ran against some of the best competition in Iowa, there were some very fast Neons (stroked) and Ecotecs and Hondas, after the race another racer who owns a Mopar dealership asked me how I got my car to run so fast....I told him I couldn't tell him while we were in the tech. area....the best part was beating the track champion that won every race he finished that year except the one that I won, he even won the next night when I couldn't go....SWEET
Now all winter to work on my car....What should I do???

 

[nehring8]

Been working on the racecar for a couple of months now (racing in a couple weeks), mostly body and suspension work (still need to get through the corners better). I have made 1 engine modification, I used a Galant exhaust manifold (which is tubing like a header) in place of the heavy cast iron eclipse manifold, bolted right up but had to move the O2 sensor into the pipe after the 4-2-1 intersections. It may not make the engine any faster but at least i dropped a lot of weight where I did not want it. Also picked up a set of 450cc injectors in a swap with a guy, probably gonna see how much more E85 I can run without the computer giving me fits.

 

[bastarddsm]

Been working on the racecar for a couple of months now (racing in a couple weeks), mostly body and suspension work (still need to get through the corners better). I have made 1 engine modification, I used a Galant exhaust manifold (which is tubing like a header) in place of the heavy cast iron eclipse manifold, bolted right up but had to move the O2 sensor into the pipe after the 4-2-1 intersections. It may not make the engine any faster but at least i dropped a lot of weight where I did not want it. Also picked up a set of 450cc injectors in a swap with a guy, probably gonna see how much more E85 I can run without the computer giving me fits.

I think those 450's might be a bit much. You'll want about 25% bigger injectors. Actually you could do it with just fuel pressure. Take a regulator apart and add an adjusting screw on the part with the vacum nipple. Then you can preload the spring for more psi. That will richen it up enough for the E85. You'll want to shoot for about 55-60psi. I'd also advance the cas just a little bit, set it to like 6*-8*. You'll have to read the plugs to get the timing an fuel right.

I used to run a similar fuel setup on my car back in the day before I had money for a real fuel system. Worked pretty good actually.

Sounds like a blast. Might need to look for a cheap FWD for myself.

 

[laserspeeddemon]

Speaking an absolutely noobs perspective, I would actually use SMALLER injectors. This way I can lean out the mixture

 

[WillRaceForBeer]

Nice read, since your car stays in closed loop and you are running e85 the larger injectors aren't such a problem, sounds like the ecu is able to correct the fuel trims within reason. To run the 450cc's you may need to find ways to trick the ecu into reading less air, there are a few ways to do this, like hacking the maf, although I have no experience with your model. Of course, your ecu may still have room to correct for the 450's. As was mentioned being able to control the Fuel Pressure by hacking a regulator would be a nice trick too.

 

[bastarddsm]

Nice read, since your car stays in closed loop and you are running e85 the larger injectors aren't such a problem, sounds like the ecu is able to correct the fuel trims within reason. To run the 450cc's you may need to find ways to trick the ecu into reading less air, there are a few ways to do this, like hacking the maf, although I have no experience with your model. Of course, your ecu may still have room to correct for the 450's. As was mentioned being able to control the Fuel Pressure by hacking a regulator would be a nice trick too.

No, the ecu is only in closed loop under ~4000RPM and 1/3 throttle. At WOT there are no fuel trims or anything, the ecu does not adjust the fuel based on the O2. All it does, is read how much air is coming it, get a afr value from the map, and inject that much fuel.

So at cruize the ecu might be able to compensate for bigger injectors, at WOT it will be super rich.

 

[WillRaceForBeer]

No, the ecu is only in closed loop under ~4000RPM and 1/3 throttle. At WOT there are no fuel trims or anything, the ecu does not adjust the fuel based on the O2. All it does, is read how much air is coming it, get a afr value from the map, and inject that much fuel.

So at cruize the ecu might be able to compensate for bigger injectors, at WOT it will be super rich.

Actually, there are a variety of conditions that cause the ecu to switch (all of which I control directly with dsmlink v3), But I was responding to the OP, where he said:

"so the ECU must be changing the pulse width to get the right A/F ratio. I don't know if it matters but I completely kill the power to my car after each race and the ECU has never gone into open loop on me"

I'm responding under the assumption that he knows about his own car.

 

[sciondan]

Not to get off topic nehring8 but have you ever ran at LaSalle Speedway in Illinois?

 

[DSMnoobsause]

Have you milled the head yet to bump the compression? If your running E85 you should be able to also are you running the thinnest head gasket you can?

 

[Arthris]

Do they check if ## car is running speed density or MAS air? if not id look into a Megasquirt 2. That way you can run the E85 and 450's bump up the timing a great deal and lean it out to about a 11.2 or so AFR. the MS2 is relativity cheap if you get it un-assembled. Or you could see if ## ECU is a eprom and socket it and burn ## own chips or run a Ostrich to tune it.

 

[Jorgen]

Don't even try running e85 unless you have a means to tune the car. Without tuning control, your car will not no how to compensate. I've run e85 and tuned with it. Putting in 30% larger injectors won't solve it, in some places you need 50% more fuel, while in others you only need 20%. Good luck racing, looks like a lot of fun. I don't know if you can get your hands on a lightweight flywheel, but that would help quite a bit I would think. It doesn't necessarily make more hp, but it allows the engine to spin up faster to get to where you do make more power.

 

[nehring8]

Wow...these are some of the more informative replies that I have got...I have milled the head, but only like .010, it runs about 225 psi gauge pressure (guessing around 11:1). Remember, I only run FULL THROTTLE or nothing, I don't care if it has any power in between...I also have a set of automatic turbo injectors (390's?) that by calculation would be about right for full E85, I have run them once before but was having fuel pump problems at the time (switched to a turbo fuel pump now), maybe I might want to try them first. GONNA SOUND REALLY STUPID NOW... So...I totally forgot that the car goes into open loop during WOT, I was only thinking of the CEL and wheter it comes on at lower RPM's, I am not into tuning, just into cheating the stock ECU into doing what I want it to do. I am really liking the adjustable fuel regulator idea...

 

[bastarddsm]

Actually, there are a variety of conditions that cause the ecu to switch (all of which I control directly with dsmlink v3), But I was responding to the OP, where he said:

Yeah, there defiantly are quite a few conditions that control closed loop, I was trying to get the point across that closed loop only effects idle and cruise type conditions.

Have you milled the head yet to bump the compression? If your running E85 you should be able to also are you running the thinnest head gasket you can?

In theory this isn't a bad idea, but there are some issues..

1. He's running stock 2.4 pistons, they don't have valve reliefs for a 4v head. He's most likly already on the edge for piston to valve clearance. Cutting the head could cause problems, nothing a steady hand and a die grinder couldn't fix tho...

2. It will change the cam timing, unless he runs adj gears. This could hurt power, and or make #1 worse.

3. You have to mill the head quite a bit to get a decent bump in compression. I seem to remember calculating it to be about .040" to get a 1 point increase on a 47cc head, and a 2.0 motor

4. A better idea might be running a 4G67 head. They have a ~42-3cc chamber, and big ports. More compression without any of the drawbacks.

Do they check if ## car is running speed density or MAS air? if not id look into a Megasquirt 2. That way you can run the E85 and 450's bump up the timing a great deal and lean it out to about a 11.2 or so AFR. the MS2 is relativity cheap if you get it un-assembled. Or you could see if ## ECU is a eprom and socket it and burn ## own chips or run a Ostrich to tune it.

They probably don't check, but if you start winning alot, they might. Probably best to stick with the stock ecu, but you can definatly do some hacks that are easy to hide.

Don't even try running e85 unless you have a means to tune the car. Without tuning control, your car will not no how to compensate. I've run e85 and tuned with it. Putting in 30% larger injectors won't solve it, in some places you need 50% more fuel, while in others you only need 20%. Good luck racing, looks like a lot of fun. I don't know if you can get your hands on a lightweight flywheel, but that would help quite a bit I would think. It doesn't necessarily make more hp, but it allows the engine to spin up faster to get to where you do make more power.

Lol.. you don't have a clue what your talking about. Enlargening the injectors by about 25% works just fine. The fuel map is soo rich at WOT on these, it really doesn't take much extra fuel to compensate. The only drawback is that it will ideal and cruise on the lean side, but that doesn't matter when you have closed loop to fix that. No that any of that even matters in this app.

Wow...these are some of the more informative replies that I have got...I have milled the head, but only like .010, it runs about 225 psi gauge pressure (guessing around 11:1). Remember, I only run FULL THROTTLE or nothing, I don't care if it has any power in between...I also have a set of automatic turbo injectors (390's?) that by calculation would be about right for full E85, I have run them once before but was having fuel pump problems at the time (switched to a turbo fuel pump now), maybe I might want to try them first. GONNA SOUND REALLY STUPID NOW... So...I totally forgot that the car goes into open loop during WOT, I was only thinking of the CEL and wheter it comes on at lower RPM's, I am not into tuning, just into cheating the stock ECU into doing what I want it to do. I am really liking the adjustable fuel regulator idea...

I wouldn't do the 390's they are way to big for what your doing. Stock injectors are like 190's You only need like 250's also keep in mind that the fuel map at WOT is very rich, so you only need to add a little extra fuel to get it right where it needs to be for power.

Do you have a cheapo afr gauge? Do the fpr mod like I suggested then go full E85 with it. I'd start with a base fuel pressure of about 60psi, you'll have to watch your gauge and make sure the pump can keep up with it. (you might have to upgrade to a a 190 or 255hp) Watch the gauge and make sure it goes full rich at wot. If it is you can back off the fuel pressure some to lean it out. You can try and read the plugs, there are several good sources on the internet.

Then I'd give it some more timing with the cas. set it to 6*-8* and try that. You'll wanna do this with a set of fresh plugs and run it hard. I'd use Autolite #64. Thats one step hotter than stock, and they seem to read easy. You'll want to play with the timing to the ground strap to have a color change in the middle of the bend. If its to close to the threads, pull timing. To close to the end add timing.

My final idea, is like above, get a 4g67 head, with the smaller chambers, and big ports. Then I'd source an EVO3 intake. I'd fill the bottom of the intake ports with epoxy so you can blend em in nice to match the EVO3's smaller ports. This will give the "higher velocity" 2g style port, with an intake optimized for a bit more power above 6200 rpm, where the 1g mani peaks at. The higher velocity port, should help low to mid range power.

 

[5taR]

That looks like so much fun. If you don't mind me asking, how much do you have in the car?

 

[2GJeremy]

He can't have much, it's a almost stock competition. 99% of mods are not allowed.

 

[nehring8]

The safety equipment on the car is what is expensive, car only maybe $4-500, cage another 150 (bent and welded myself with the use of my works bender), seat 100, belts 50, helmet 200, etc...you could get a car going hard for $1000 if you did all the work yourself. I really like the 4G63/4G64 combo for racing, can build a replacement motor for couple hundred dollars and I have not broke my first one yet. Actually the only engine I ever trashed was a 4G63 when I spun a balance shaft bearing (eliminated that on all my engines now). I really appreciate all the creative ideas, I can't afford to build a motor with new parts cause if I did I wouldn't have any money left to race with (all said and done last year I made a couple hundred bucks racing, can't beat making a little money and having fun doing it)

Stock injectors 240cc, when I went to the 2.4 engine I went to 275cc galant injectors if I add 40% for E85 I get 385cc (thought 390'c would be good)
Your comments on the maps being rich at WOT helps me understand why the 275cc injectors are working

When you build a 4G63/4G64 motor you are off about 1/2 a tooth on the cams, I retarded both of mine to get more dynamic compression at higher RPM's, I do not drop off all the way to 7500

Last time I looked at my plugs the heat zone was right at the bend, E85 makes them a bit harder to read as far as rich/lean in my opinion

I will see if I can find another video of one of my races to post

Boone - YouTube

This was one of the biggest races in the US, the boone supernationals, best cars from 6 midwest states, unfortunatley my car had a bad gear for the track, only getting 6000 RPM by the end of the straightaway, ran the middle of the pack the whole race, move up a couple positions and ended up 13th

 

[laser90]

It looks like a BLAST! Good luck this year.

 

[bastarddsm]

Stock injectors 240cc, when I went to the 2.4 engine I went to 275cc galant injectors if I add 40% for E85 I get 385cc (thought 390'c would be good)
Your comments on the maps being rich at WOT helps me understand why the 275cc injectors are working

When you build a 4G63/4G64 motor you are off about 1/2 a tooth on the cams, I retarded both of mine to get more dynamic compression at higher RPM's, I do not drop off all the way to 7500

Last time I looked at my plugs the heat zone was right at the bend, E85 makes them a bit harder to read as far as rich/lean in my opinion



This was one of the biggest races in the US, the boone supernationals, best cars from 6 midwest states, unfortunatley my car had a bad gear for the track, only getting 6000 RPM by the end of the straightaway, ran the middle of the pack the whole race, move up a couple positions and ended up 13th

Realistically, you should be really rich at wot with them 275's. The ecu/maf will be able to read the extra air the 2.4 is taking in so it should run fine with the 240's. Running the 275's is probably why you can get away with running a decent amount of E85. I'd bet it's rich enough you could do full E85. I'm not 100% sure but I'd suggest the stock fuel maps are in the 11:1 or even richer area at wot. You can do some simple math and see how much bigger you need your injectors to be to get it down to about 8.5:1 for E85.

Your right about E85 making plugs harder to read, it really doesn't leave much color.

You might look and see if a turbo trans is a better ratio for you, or even an AWD trans(you can weld the cd and run them)

 

[nehring8]

Went racing on Friday night on the half mile track against 4 and 6 cyl's, car ran great and handled even better...I cut all of the springs to drop the whole car about 2 inches and drilled a hole in the rear struts and changed to heavier oil and welded back shut (car was doing some serious drifting). Beat all of the V6's but a really fast 4 cyl cavalier got out front on a screwed up restart and got way ahead, I caught back up to him in a couple laps but could not pass cause he was using the whole track, oh well got second, even beat a 3000GT with a 5 speed and a taurus SHO.