PROJECT 86

Since you have to sandwich 2 plates in between the small port head and big port intake manifold I decided it would be a better idea to just use the intake manifold originally intended for the small port 4age. The sucky thing is it points the wrong way so you have to get it re-welded to point the correct direction. Since I was chopping and welding I figured why not throw a 7mgte (Supra turbo) throttle body on it instead. It's 60mm vs 55mm on the stock 4ag unit so why not give it a shot. The idea behind using a larger throttle body is to give less of a restriction for the air entering the engine. For naturally aspirated motors since air is not being forced into the engine it has to suck everything through that 1 opening. It's pretty rare that you don't see a n/a car not pick up at lest a couple of hp from this, even if it seems a 55mm throttle body is plenty for the whopping 95whp my corolla is making at this point.

Right: Supra 60mm throttle body vs. Corolla 55mm throttle body. Left: bigport intake manifold vs. smallport intake manifold w/Supra throttle body adaptor plate.

The other big change is the small port intake manifold. With the tvis manifold you can run 2 small runners to each cylinder and have a set of butterflies sanwitched in between the intake manifold and the cylinder head. At low rpm's the butterflies are closed thus blocking off half the runners to force the air through 1 small intake runner into each cylinder. This keeps the velocity of the air higher and can cram more air into the cylinder in turn making more hp and torque. At a specific rpm (in this case about 4400) when the engine is about to be choked off by the small runners, it opens the butterflies and air is now being sucked through 2 runners per cylinder. There is a small dip in power then power shoots up agian. At high rpm's the 2 intake runners are optimum as the engine needs more air to make power. You need this in the bigport engine becuase the intake ports in the head are so big the air is moving too slow to generate any power at low rpm's with the tvis disabled. With the small port head the tvis is just one more thing in the way so I'm switching to the intake manifold that was desgined for it. I had it all welded together for $90 at the machine shop. When it was finished the only problem was making the Corolla throttle linkage fit the Supra throttle body. It took some time with a grinder and a power drill but eventually I got it working. The throttle plate was sticking a lot so I put 2 return springs on it to keep it from doing this. Once it was on I went out for a test drive. The car once again seemed to pull much better than before, I was pretty optimistic of getting to the 100hp mark on the dyno. Once on the dyno I was suprised to see what a real improvment it had made. Power was up by 10.1hp and there were gains in the 15-20hp range near redline. Keep in mind I did no other tuning to this car. Even in low rpm's the new intake manifold seemed to be making a little more power than the tvis manifold. The only reason I could see to gaining so much over the tvis manifold near redline was the tvis butterflies and the angle of the adaptor plate could have been causing some sort of flow problems above 6500rpm's. In all the small port head/ intake manifold and supra throttle body added a total of 18whp and 13wtq over stock.

60mm throttle body + small port intake manifold - 105hp

PART 4 - HEADER, CAT, EXHAUST

After getting the engine running good with some factory toyota parts it was time to start buying some aftermarket parts. When I found obx's ae86 header it was nice to see a new company making parts for such an old car. I'm a bit skeptical of OBX's parts. Their lsd exploded in my Del Sol. It was about $220 shipped for the header. When I got it I was suprised on how good it looked for a cheapo header, definately better then I thought. My only problem with it is the 2.5" collector where it necks down to 2.0" There's no gradual step down, rather a 2" pipe that bolts to a 2.5" pipe.

Left: 2.5" aftermarket cat vs. stock ae86 cat. Right: the top pipe is the flange at the collector, on bottom is the flance that connects to the collector. 2.5" collector into a 2.0" midpipe didn't seem like a good idea.

I dicided to get the bottom pipe re-made or re-welded to get rid of any last restrictions in the exhaust. After the header I had a 2.5" high flow cat laying around. I decided this was a good time to use it. For the rest of the exhaust I went with a dynomax 2.5" muffler and 2.5" mandrel bent piping I was going to route under the axle. It was to be a pretty big exhaust for such a small engine. I am assuming there will a loss in power in the bottom end. I would rather have my car grow into it's exhaust later down the road then spend a bunch of money and have it be too small after I'm done modding it. I installed the OBX header and found one of the bolt holes doesn't quite line up. If you have a power drill laying around this isn't a problem. With the header on it was time to put on the rest of the exhaust. I drove it to the muffler shop and had the cat and muffler put on. We did the exhast under the axle to keep things simple.

When he finished and fired it up I was pleasantly suprised with how good it sounded. Not much louder than stock with about as much rumble as you could ever expect from a 1.6. In all the exhaust including the header and muffler cost about $430, not cheap. I was thinking an exhaust wouln't do much for a nearly stock engine so I waited a bit to get it done but with the old exhaust falling apart now was a good time. This wasn't just a performance mod but a repair. Once it was done I took it for a few laps around the block and let Mat and Lil' Mike get stupid in it. It felt pretty good. The low end power seemed as good or better than before with the car pulling strong in the upper rpm's. I took it to the dyno on a 110 degree day so I'm assuming the dyno re-calibrates for different weather conditions. At at the dyno they had all the fans going so the temperature inside was only 94 degrees wich isn't too far off my past runs. After a warm-up run it made 112hp and 94tq at the wheels. A 7.5whp improvment over my last run. The thing that really suprised me was how much power it gained in the lower rpm's. There was a 5-7whp gain from 3000-4600rpm's. Everyone says that 4-1 headers and big diameter exhausts are only good for top end but I would say this proves that wrong. I've read recently from a few experienced engine builders that 4-1 headers and larger collectors actually make more power throughout the powerband. It seems like maybe 4-2-1 headers and small exhausts making lots of torque could just be an old wives tale. This is a big straight free flowing exhaust never going under 2.5" on a 112hp engine and it made some pretty drastic improvments. This exhaust should be good for anything a 4ag can dish out n/a or supercharged. It seems the only place it didn't make a large increase is in the 5000rpm range where none of my recent mods have seemed to make any differnce in power. This leads me to believe that stock the 4ag is optimized for this area of the powerband with a large increase in torque around this point. Despite only gaining 1wtq on my last 2 mods the powerband has flattened out quite a bit with a lot more useable power. Just another example of peak dyno numbers not telling the whole story.

exhaust installed - 112hp

obx header vs. stock ae86 header. The obx unit is 13 lbs. less.

PART 5 - CAMS

When I put on the small port head I actually had the whole engine. Instead of putting in the small port block I decided to get some work done to it first. On Ebay I found a set of 82mm toda 11.3:1 pistons for a 4ag with rings for $350. Since Toda is top of the line this was a pretty good deal. The factory pistons are 81mm so the block was going to have to get overbored. You might think adding 1mm to the pistons is silly but it works out to an extra 40cc's of displacment. Going from 1587cc's to 1627cc's is worth while on such a small engine, especially if your buying new pistons anyway. On the red-top blocks toyota decided to beef it up with extra ribbing on the block (7 vs 3) and a stronger nickel/iron alloy. On the small port blocks there are also oil squirters located under the cylinders to help cool things down. With the stoutness of the 7 rib block overboring 1mm is no problem. Some manufacturers have 2mm oversized pistons wich would be pushing it but probably still do-able. Some other differences between the bluetop and redtop is beefier rods and 2mm larger 20mm floating wrist pins. Also the rod bearing journals are 2mm larger. No doubt they did this so they could add a supercharger and is a little overkill for n/a applications. The rotaing assembly ends up heavier so if the overbore is kept to 1mm max the bluetop block would probably be better for n/a but it's all subjective.

left: pair of smallport rods all balanced and clean, very stout looking for a 130hp engine. right: smallport 4ag block bored out to 82mm

While the engine was being overbored I had the rods and pistons balanced. The pistons were all within .1 gram of eachother but the rods were a different story. The factory toyota rods were 7.2 grams off from the heaviest to the lightest. Basically you want all your rods and pistons to weigh the same. Spinning all the those pars at 8000rpm's a 2% difference is a ton! Imagine running with one shoe that's heavier than the other, not good. With everyting balaced and cleaned I bought new bearings and began to assemle everything.

Left top: set of toda 82mm 11.3:1 pistons for a 4ag. Left bottom: bare block with oil squirters installed. Right top: installing pistons in block. Right bottom: all the pistons in the block (yes 2 rods aren't connected but it looked cool)

Assembling an engine is pretty easy. If you have a repair manual it will have all the torque specs and clearances in there. It can get a little tedious measuring everything over and over again but a little patience now will result in a good running engine that should last for years to come.

When re-building a block there are quite a few things to consider. What do you want out of it? What future mods do you have planned? How big is your budget? If you plan on turbo you obviously don't want to get high comp pistons. Or if your boosting you should keep the cylinder boring to a minimum. If you want higher compression, pistons are usually the best way to get it but not the only way. If your block is in good shape and you just want a little bump in power sometimes milling the head can give you a nice increase. If your block does need a re-build there can be many factory pistons to choose from before resorting to the aftermarket. In the case of the 4ag there are 4 different compression pistons you can use in the 7-rib block. Once you have a goal set and you start ordering parts there are many different things you can do to the block while it's apart. For a basic re-build you can just hone and re-ring it and replace the bearings. After this you can (but it's not manditory) balance the rods and crankshaft. Replace the oil and waterpump. Get arp fasteners, headstuds, overbore for extra displacment so on and so on. Some people even get parts cryogenicaly frozen and buy all aftermarket internals for the block. All this can get very costly and you might have a few thousand dollars into and engine that goes in a $800 car. Sometimes you have to know when enough is enough and if it's really cost effective to drop so much money on a engine you can get second hand for a few hundred dollars.

When building an n/a engine choosing the compression ratio is important to getting the best performance out of your other modifications. A high compression ratio will not only increase overall power under the curve but help things like ported heads and big cams run good in the higher rpm's. The drawback is you need higher octane gas to run higher compression. Since the higher the compression you are generating more heat and cylinder pressure. Higher octane gas is less combustable allowing it not to ignite until the spark plug fires. If you use low octane gas in a high compression engine it can ignite before the spark plug fires. This wants to push the piston down while it is still traveling up in the cylinder generating a lot of force on the pistons since it's being pushed in 2 differnt directions. This is how you break ring lands and crack pistons. You can combat this a little by changing your timing to ignite sooner or richen your fuel to lower cylinder temperatures. Both usually rob power so your basically raising your compression for nothing. How high you can go on your compression can be effected by your tuning, engine, and gas. There is not exact amount as to how high you can go safely. I've done 11.0:1 on a 4ag without problems so installing 11.3:1 pistons shouldn't be too big of a deal, I hope.

Top left - 9.4:1 4age bluetop piston. It's pretty much a flat top piston, no teflon coating, pretty dirty. Top right JDM 4agze 8.9:1 compression piston. Slight dish to it. Comes teflon coated. This was one of the pistons from my old 4agte. You can see where the detonation killed it.

Bottom left 8.0:1 4agze pisons. Bottom right 10.3:1 smallport 4ag pistons. You can see they both come teflon coated from the factory. The 4agze pistons are dished while the smallport pistons are domed. The size of the dome or dish is how 4ag's get their different compression ratio's.

I couldn't get my hands on my engine hoist on the day I was installing the block so me and mike just lifted out the old one and put in the new one. It was actually very easy. When the block was out I used some simple-green on the engine bay to clean up all the sludge. Most of the time it's easiest to install the fully assembled engine and tranny at the same time but I'm kind of lollygagging as I'm waiting for parts and screwing around with the head. I also decided with everything taken apart to do some cleaning up of my wiring by re-routing some of the engine harness under the dash and though the fenders to give the engine bay a little cleaner look.

Top left - cams out head just about ready to come off. Top right - head is off old block sitting in the engine bay. Bottom left- new block in with some arp head studs installed. Bottom right- engine all put together. Notice there are a lot less wire visible, should make it easier to take apart in the future.

After some serious lollygagging I decided to buy an extra smallport head to put on the block since I was porting out my old one. Once it showed up I finished putting the engine together. I was a little nervous starting it for the first time becuase I had ripped apart my engine harness, taken out all the wires I didn't need and re-routed all the igniton stuff under the dash and through the drivers side fender.

The car did start on the first try. After letting it run for about 20 minutes I changed the oil (use mineral based oil on a fresh rebuild) and took it out for it's first test run. Initially the car seemed to be running a little rich with the 240 injectors and was pretty sluggish. After a few miles it seemed the ecu was picking up on this and the gassy/buring cat smell gradually went away. Since I used an Mr2 crank pulley on the new engine the timing marks were off. Also I'm running an Mr2 cap/rotor so I wasn't exactly sure where to set the timing at. I advanced it a little and the car picked up a lot of torque on the bottom end. I kept messing with it and listening for detonation to try to get it close to where it should be. After about 15 miles of driving and some timing adjustments the car was beginning to feel much better. I always set the timing on the dyno so I wasn't too worried about where the marks are for it. I still couldn't really get on it yet but I think I may have picked up a few hp with the new block. Raising the compression on a nearly stock engine isn't going to do too much but should help with future mods such as cams/head porting/and possibly larger valves. After breaking in the car over the span of about 3 months (yes I lollygagged quite a bit) I finally went to have it dyno'd. On the first trip the car only made 105whp and was missing badly over 5500rpm's. I took it back home and discovered one of the injector plugs was broken. I replaced the the injectors with a set of 7afe injectors (I think they're 185cc?) bypassed the resistor box and put in the newer better injector plugs without the crappy metal clips. The car was running good again and I went back to the dyno. This time it made 118whp and 100wtq. Only 6hp/tq over the last dyno but a solid gain over 4000rpm's. Was it worth the $500 I spent doing this? If I stopped here not really but it will help in the future so maybe not such a bad investment. At this point basically I have an entire smallport engine with a few bolt on's. If I had to do it over and not step by step like I have been the best way to get similar power would be to just buy a smallport for like $400, mill the head some, clean it up throw some bolt on's onto it and you're good to go. If I had used synthetic oil and maybe tuned the cam gears some I might be able to get a little over 120whp wich isn't bad for a car that just passed emissions a few weeks before writing this.

high comp vs. low comp block - 118hp

PART 7 - HEAD PORTING

When the factory produces cylinder heads there can be small imperfections in the machining process that go along with mass production. Usually cleaning up these flaws can result in a slightly better flowing head. When working on a cylinder head you should remember that to the novice it's a lot easier to do more harm than good. A lot of people just want to go crazy with the dremel and sand eveything to a mirror like finish. Having ports that look pretty has nothing to do with performance, it's only asthetically pleasing and it's also inside your engine so who cares if it's shiny? I myself am a novice and don't want to do a lot of work to this head. That being said I'm also not going to write a whole lot about the "black art" of head porting as it would take forever and I don't really know what I'm talking about. For this engine I'm going to only be smoothing out the sharp edges in the combustion chamber as this reduces the chances for hot spots wich can cause detonation and maybe some minor smoothing the ports. A large increase in flow at low lift can also be achived through a 3 angle valve job. A 20 year old engine can usually benefit from a valve job anyway and you can gain as much flow through a valve job as you can through a basic port/polish and it can cost a lot less without the risk of fucking something up. I'm not going to do that just yet as I have not decided weather or not to get oversized valves so I'll save that for later. When starting on this head I noticed for an import (I compare most things to Honda engines) there were a lot of areas that could use some work. Really compared to my Civic the 4ag head looked like shit. In the combustion chamber there were a lot of sharp edges where the valve seats had been cut out. I smoothed out all the sharp edges. In the process I'm removing material from the combustion chamber so it will lower compression. To offset this I'll have the head skimmed .020 but the compression still probably dropped to about 11:1. Also when messing around with combustion chambers it's a good idea to get something to cover the combustion chamber with and use a graduated cylinder or something like that and measure the cc's of the combustion chambers to ensure they are all equal. There's a formula to figure out my new compression ratio but I don't really care weather it's 11.13 or 10.92. I have a general idea and that's fine. There's not a whole lot I can do to change it now.

On the intake side of things you really don't want to hog it out or polish it. I kept the edges a little rough and just cleaned up the small bumps and stuff. There is also a small area just below the valve seats in the intake/ehaust ports where the valve seats were cut in that you can smooth out. I didn't really do much to the intake side besides smoothing this out and hogging out the ports slightly. On the exhaust side of thing this same area (about an inch or so after the valve seat of the floor of the port had a really bad angle that you could feel with your finger. I took a lot of time smoothing this out and cutting out the section of the valve guide that protruded into the exhast port. I sanded the whole exhaust port to a very smooth finish. So now at this point all the sharp edges in the head have been removed. Since material was taken out I was expecting a small loss in power in the lower rev's. Since I don't really know what I'm doing and this is all done in my spare time it was basically a free mod. After gaskets and dremmel bits I probably have about $100 into this. I was hoping to pick up as much as 5hp on the top end but I really wasn't holding my breath. I figured my chances of losing power were about as good as gaining power.

Sorry, Pictures aren't that great. I'll be interested in seeing what a home port will do on a dyno. Because of this I got a spare head. All the sharp spots in the combustion chamber were taken out, hopefully this will reduce hot spots.

above - intake side. It need so not be totally smooth but I did go over it with some 80 grit after these pictures were taken so it's a little smoother than what you see in the pics. Below - exhaust side got really smoothed out. You can feel with your finger the sharp parts where the machining was less than perfect. These got smoothed out, hope it works. After the head sat for many months collecting dust I needed to wash it off. don't let anyone you share your shower with catch you!

after dynoing it with the high comp block I let Mat borrow the car for a month or so and the day I got it back the new head went on. As you can see by pics of my engine bay, swapping heads only takes a few hours. When the new head was on I took it for a spin. I car felt noticably more sluggish and I was about to go home and re-check the timing. I took one run to redline beforehand and around 5500rpm the car seemed to pull really hard. I went and had Mat drive the car and he said it seemed to pull better on the top end. It seemed it turned out as expected, loss in low end, gain in top end. Once on the dyno my butt-dyno proved to be accurate. On the fisrt pass the car made 121whp with steady gains past 5500rpm but a slight dip in power below 4000rpm and a big dip in the 2500rpm area. With the less detonation prone combustion chambers I was able to advance timing 2 degrees and advance the intake cam 2 degrees (milling the head .020 throws off the cam timing by almost this much). After these 2 changes the low end was back and it had a dip at 7200rpm but it still was hitting 121whp. I don't really care what the car does right at redline, mabe if it could go past 7400rpm, but it can't so the tuning was left like this. I'm sure a pro could have done better but that's also not free.

ported head - 121hp

adjustable cam gears

 

When I was porting the head I bought a set of fidanza adjustable cam gears. Before I had 1 aem cam gear on the intake side that I had messed with a little but saw no real difference with. I like the look of the fidanza gears much better. Cam gears are a nice little tuning tool bacuse with them you can move around your power band a little to suit your mods or driving style. On the dyno some small adjustments helped gain back lost power with the milled head. It's also a good way to dial in aftermarket cams or compensate for thinner head gaskets. Usually advancing the intake cam gives you more bottom end and less top end, retarding it does the opposite. The opposite is true on the exhaust side. I didn't spend a lot of time tuning them since I picked up a set of HKS cams so they will be re-adjusted for my next dyno.

Left to right - bigport (bluetop) cam gear, .89lbs. smallport (redtop) cam gear, .77lbs. AEM cam gear, .575lbs. HKS cam gear .70lbs Fidanza cam gear .535lbs......Lighter is better.

 

150hp 4age

Well at this point the car is making about 150hp at the crank. Not only has it gained back the 7 or 8 hp it was short of the factory rating (I'm sure it made 112hp back in 85 but in 2005 it had seen better days) but gained roughly 35+hp on top of that and about 25 lb.ft of torque. The car is still emissions legal (not visual in california I'm sure but in Az it passed the sniffer just fine) idles smooth and besies being loud runs just like stock. I'm sure it's capable of 160hp or maybe even a little more without having to resort to aftermarket cams or standalone but for anyone looking for streetabily and asking the question "how do I make 150hp from my 4ag?" there's one way to do it.

PART 8 - HKS CAMS

Left - HKS 272. Middle - HKS 264. Right - Stock bluetop

I picked up a pair of HKS cams off the Mr2 board for $450 with HKS cam gears. Since I didn't end up using the gears I sold those off and installed the cams. Since I already went over cam installs in "part 5" I'll just get right to the performance aspect of things. The intake cam was 272 duration and the exhaust 264 duration both with 8.35mm of lift. The idle was decent with these cams and the car ran seemed to run good over 5500rpm's. Driving it around town I noticed that the car seemed to not rev high engough to make good use of these cams. Every time I would shift even at redline it just seemed to lose so much power. The car really need to pull to at least 8000rpm's with these. I went down to the dyno to see what they could do. On my first run the car made 118whp/94tq, a pretty significant drop from my last dyno. Again with losses ar every rpm. They told me at the dyno that the apex-i grounding stabilizer worked wonders on their Honda's. I intalled one on the dyno after a few warm up runs with the cams. As soon as I hooked it up the idle smoothed out and on my next run the car made 122whp/97tq. An improvment of 4.5whp and 2.1tq with most of the power coming on at high rpm's.

Apex-i superground HKS cams - 122whp

apex-i super grounding kit

tuning my cams

It was obvious the car needed tuning. First I messed with the timing a little. The car would make 127whp with the timing retarded a few degrees and it smoothed out the 7000+rpm zone but the loss in low-end was substantial so I backed it off a little from it's original settings. This fixed the choppiness but hurt low end slightly. To get some low end back I set the exhasut cam to -3 and the intake to +2 (after many, many pulls) In the end all I could get was 126whp/100tq. With the timing retarded they were a few tenths short of 130whp. The loss in the low end was just too much. You can see in the dyno they need to be revved to at least 8000rpm's and standalone would probably help a lot (even though my afr was good with the stock ecu).

HKS cams tuned - 126whp

 

the future of this project

As of the day before I dyno'd the cams I sold this car to Mat the other owner of this website. We pulled the cams out because there will just be too much tuning involed and he doesn't want to be doing a lot of work to the engine. We are still going to be putting the 7a block in it for one final mod (guessing in the high 130whp range) but this will probably be the last modification done to the engine. I'm sure at one point he'll clean it up and get it painted. It would be nice to see some pretty car pics on here.

Thanks to all the people who have helped me with this project and all the positive e-mails I've recieved from people. I wish I could have gotten more out of this car but who knows maybe after the 7ag Mat will want to mess with it some and it will live on. It's not like I didn't like this car but there was a te27 I had to have so this had to go and I'm starting my project crx which you can see at the bottom of this page.

 

PART 9 - 7A BLOCK (1840cc)

Fist off I would like to thank Aaron Willis for all his help on this website. There probably would never have been a "part 9" without him. If you want to check out how to build and tune a 7ag and why a properly built one is actually a viable option to the blacktop or 4agze check out this website Last I checked his project was going a lot better than mine. The 7afe is found in mid 90's corolla's, prism's, and celica's. It is basically a 4a block that has been stroked from 77mm to 85.5mm resulting in an extra 175cc's of displacment. You can remove the less desireable and harder to install 7afe head and put your 4ag head on with a few tricks. This produces the "7AG". Basically it's a lower revving torquier version of the 4ag. With weaker rods and a slightly worse rod stroke ratio it doesn't have the capability to rev as high as a 4ag but with a 7500rpm rev-limiter this is not a problem. Perhaps if constant 8-9000rpm pulls were made I would keep the 4ag but that will never happen in this car. I picked up 2 7afe engines at the junk yard for $150. Since the 7afe has dished pistons you want to find some 4ag pistons to put in it to bump up the compression a little. Redtop 9.4 or 10.3 pistons work perfect. The longer stroke and thinner 7afe metal head gasket will give you around .7 higher compression then whatever the 4ag cams are rated at when used in a 7ag. If you use 9.4 redtop 4ag pistons you will actually end up closer to 10.1:1 compression. Now I have put together a few 7ag's before (2 turbo, 1 n/a) and I've gone the 4ag piston route before. Using a standard sized 81mm piston will get you 1762cc's. You can get 81.5mm 4ag pistons and get 1784cc's or go aftermarket with wiseco's, toda's or something and get more. With me however since the motors were so cheap I wanted to keep things that way. After a little research I found that 86-89 Accord's (a20 engines) have 82.75mm pistons with the same wrist pins as the 7a. I got a set off ebay for $19.95 shippped with new rings and wrist pins. Getting the block bored .070 over (1.75mm) will give you an extra 78cc's of displacment resulting in 1840cc's. This is 253cc's bigger then the 4ag started out or about 15% bigger. That is quite a difference.

Above - 7afe head removed. All you need is the block. Below - 7a piston left, A20 pistons right. The compression height is almost the same and the 7a wrist pin fits perfect in the A20 piston.

I took the Accord pistons and 7a block to the machine shop to get fitted up and they thought I was a little crazy but after looking at things they said it could be done quite easily. Really 3 things had to be done to make them fit. 1 - boring the engine .070 over. 2 - grinding down the bottoms of the A20 pistons to keep them from hitting the crank as they are longer than 7a pistons. 3 - milling the block about .020 since the A20 pistons sit slightly lower in the cylinder than 7a pisons.

Left - 7a rod vs. 4ag rod. Right - A20 piston vs. 7a piston. You can see how similar they are (the 7a piston is the dirty one)

 

reducing weight

since this car was trashed to begin with why not take a few things out lighten it up. Whenever you remove weight from a car it will not only make it faster (less weight to push) but stop better (less weight to stop) not to mention handle better depending on where the weight comes from. Now that my Corolla is on a diet I can weigh all the stuff coming out of it.

spare/jack - 35 lbs.

front bumper support -31 lbs.

back seat/rear seat belts - 31 lbs.

all ac stuff under the hood - 31 lbs.

under dash heater/ac - 22 lbs.

sound deadaning (tar) - 22 lbs.

misc. - 19 lbs.

power steering - 16 lbs.

obx header - 13 lbs.

carpet - 8 lbs

TOTAL - 228 lbs.

CAR WEIGHT - 2000 lbs.

wheels, suspention and brakes

With all this attention going toward the engine it's about time to make it turn and stop a little better. First thing to go were the hideous factory wheels. I found some 14" 83 Supra wheels cheap and put 195/60's on the back and 185/60's on the front. The car had a much tougher looking stance but still retained that factory look. I like the old school 14's. It makes me sick to see big chrome wheels on such an old car, I like to keep it "old school". With the more aggressive wheels it was time for a more aggressive stance. Mat had some Accord coil-overs sitting around so I went to work making them fit on the Corolla. It took some sanding and cutting but I made them work. While the suspension was apart I put on some new factory brake pads, rotors, struts and wheel bearings. The brake lines looked like they had seen better days so I replaced them all with braided steel lines. With the new wheels and the stiffer springs the car handled much better. It's still a ways from where it could be but it takes the turns pretty well.

left: coil-over installed on ae86 strut housing. middle: everything on the car except the new brake lines. right: braided brake line vs. factory brake line.

 

 

BACK TO MAIN

 

Some other good corolla and 4ag related sites

everything 4ag - www.club4ag.com

lots good info with dyno's and some track video's - www.garagedori.com

Lots of mr2 info - www.mr2oc.com

 

PROJECT CRX

 

Above - showing the hood some real speed