Modifications

Modifications performance gains VS. How much they cost.

A. Intake: My first upgrade was the intake. I bought my friends Akimoto intake pipe and K&N designed for his Prelude SRV. I cut the pipe and made a simple mount for it out of bendable aluminium. This costed me 60US$. After I removed to stock intake I realised how restrictive it must have been with all those empty containers to absorb sound. I couldn't tell if this helped performance but i did stopwatch faster times by ~0.1 seconds. Update 18/9/99 I discovered that the closer the airfilter to the intake hole (going as far down as possible) the more power you'll gain. I discovered this on the track dropping my 1/4 mile times by over 1/10 of a second!

B. Cams: My second upgrade was to swap the camshafts. This was quite risky cause I didn't know or heard of anyone who has done this before. I searched around for custom cams and got some expensive quotes etc?At the end i decided to buy them from MR.2 performance products. They arrived late but were packaged VERY well and the product looked fine. I changed my timing belt at the same time and advanced the timing to gain back the low end that was lost (actually now that I look at the dynos, I think there is a gain). When I got the car back and drove off, I didn't notice a huge difference. I noticed that the car was smoother but idled at 850RPM. It took a couple of days for me to realise to what extent my 2 has changed. The biggest difference was that the power lasted a lot longer than it used to. All the way to redline it went even on 5th where I hit 219km with stock tires, a friend in the car and the Tops off! Later on, I Gteched it with a friends Gtech and clocked 6.7seconds to 60mph. The cost of this mod is 629 for the cams and about 400$ for the timing belt and installation. I do have a cheap mechanic though?

C. Throttle Body: After talking a lot with MR.2 P.P. I was told The TB mod would be a good idea since the Stock TB's diameter was even smaller than the 1.6L 4AGE Toyota engine!!! So I bought it for 239$ I installed it myself which was fun for the not so mechanically inclined person. Do remember to change the 1$ gasket if you plan to do this. I didn't notice any gain with this mod. I may have even lost a bit. The reason being was because I didn't match port my intake to the TB so there was a thick rim restricting flow. About a month later, I finally got it ported beautifully for 27$ (great deal!!). Then I noticed a difference. I felt a little more punch in the midrange. While I was removing the TB I decided to bypass the coolant hose that goes to the TB. This should keep it a bit cooler and add some theoretical power :)

D. Exhaust: did this mod because I had headers coming in with bigger diameter piping, I bought a 6? round Dynomax Ultra Flo muffler for 109$ from www.A-1performance.com . It weighs 9lbs (compared to 26lbs stock muffler) and has a 2.5" inlet and outlet diameter piping. The muffler is basically a pipe when you look through it and is pretty loud! I had some custom 2.5? piping done and positioned the muffler going straight out the middle. I had to cut the grill and custom make the mount. The piping was very poor and flowed very bad. I noticed a BIG gain in low end to the point where it almost felt supercharged. I got it dynoed and noticed around 5lb.ft torque loss after 3500 rpm :(. I'm gonna get this fixed soon. Well i replaced the Exhaust with an MR2 Turbo OEM unit. It works well. I still need to fix the pipe though. The Turbo muffles the sound alot better and sounds good. I replaced the Dynomax one cause it was too loud for daily driving.

E. Headers: I got my headers form RPM for 250$ ceramic coated (list price 340$) I got a deal because i told him I will supply him 2 dynos one before then one after to show the performance gains. This advertises his product and I get to find out if they really work. I recently put them on and can assure you the gains are Very big! The second I drove off, I noticed some loss in low end (it went back to normal) and lots of top end power! I took it to the highway (when it was deserted at 2AM) and did a high speed run. At this point my car has 215 tires which means the speedometer reads 2% less than it is really doing. I amazingly hit the redline @ 139mph (224km/h) without struggling. I can only imagine what it can do with a bigger 5th gear. Unlike before (it used to take a while) it accelerated strongly until it bounced at fuel cut. When I took a look at the stock headers and catalytic it's easy to see why it's easy to squeeze power out of there. The catalytic flange is bent where it connects to the exhaust and the heavy headers are not equal length.

F. Port and Polish: Since the stock head doesn't flow very well and since i was changing my clutch, I knew it was time. Ken Nitta who also has a NA MR2 did this mod and dropped his 0-60 time by 0.4 seconds on average! He got his done by DPR (stage 5) I'm getting mine done here by my mechanic who's done match porting and polishing many times for race go-carts, competition rally cars etc... He's charging me a sweet 350$ plus gaskets for the job. While he's at it he'll also shave the head to increase the compression ~100$. Since my car is in the shop with the enine out of the car, I decided to rebuild it (new rings and bearings) while I was at it and since i was going to increase compression to ~10.0 from 9.5 by shaving the head, i wasn't sure the old rings can hold for another 80k miles with my driving. The following has been done to the head so it can flow more and better:

            1. 3 angle valve job
            2. the valves will be reseated perfectly to avoid any blowby.
            3. The valve guides have been machined and are now conical at the tip.
            4. The exhaust ports where a few millimeters smaller in diameter (compared to the gasket) and have been ported all the way through... the intake is being ported too...
5. the exhaust gasket and hedders will be increased slightly in diameter.

G. Ignition system: I never really believed in ignition mods but after hearing good low end gain, I figured it'll eventually pay for itself (fuel economy). I go mine for roughly 50$ from Cyberspace Auto Products... When i firs put it on, i noticed the car started up really fast. That in a way told me i was working. The only problem is that the coil is too powerful for the stock wires...they will disintegrate within a few weeks (first the coil to distributer cap wire...and then the ignition wires. I had wire problems till i finally replaced mine with a set I custom made out of 7mm wire (the important thing was that the thikness of the wire inside was many times thicker than stock!) (i didn't have time to wait for a new set to come in cause the car didn't run and i needed it.) The wire set was garanteed for life and i had already tested the brand on the coil to ignition wire. It didn't show any sign of wear so i knew it would do the job very well. The custom wires costed me 17$ (i saved ~120$ and time:) I would recomend getting a set of magnecors those who don't want to venture into the unknown :) Now the question arises: Is it worth upgrading the ignition? To do this it would cost 50 +130$=180$ no cheap but since it'll pay for itself in time, it might not be a bad idea. Also, i the power gain is noticeable but not on top end. I would probably do this mod after the hedders and intake. I also don't see the need for and upgraded igniton computer. I think that's overkill.