Project TPI!
In my quest for more power out of my RS, I have decided to swap out the tired ole Throttle Body Injection and replace it with Tuned Port Injection.
WEEK 1
I have finally obtained a complete TPI setup. The only parts missing were a throttle body, computer, and a few little pieces. I practically stole it for $150 bucks. The plenum has already been ported, but I plan to gasket match up the runners to the plenum and base. I was planning to buy a 52mm BBK throttle body but I met this guy at a local car show who said he would sell me a stock TB for $50 bucks. So, I bought it. An air foil will be installed plus a custom MBA throttle body plate. I will also polish up the intake myself along with the runners. The TPI will be bolted together with stainless steel allen head bolts which will be polished as well.
 Almost complete TPI. |
 Wiring Harness. Argh! |
WEEK 2
I have been smoothing out the runners in the intake base. Also, bought some stainless steel allen head bolts. These bolts look really nice when polished. I will use these for all the runner bolts, TB bolts, and map sensor bolt. Also, me and my friend laid out the wiring harness. Whoever took out the harness yanked out every damn wire there was, however it looks like it might be somewhat compatible to my existing TBI harness. I still need to buy a computer, pump, and other accessories.
WEEK 3
Cleaned all the oxidation and gunk off the throttle body with a good bath in chemicals. Added a Hypertech air foil. I then took the wire brush from my rotary tool and cleaned off the coating on the TB which is put on their from the factory. The wire brush is great for shining it up, although it is far from being polished smooth. After a good cleaning with the brush, I installed one of Thunder Racing's logo TB plates. It is anodized black and CNC machined. Looks very nice. I also ordered many accessories from Street and Performance: braided throttle cable kit, billet throttle bracket, fuel mount pressure gauge, aluminum distributor cover, EGR block off plate, all necessary gaskets, and a bolt kit for the coolant housing. I hope to get this any day now.
WEEK 4
Received all the accessories I ordered from S&P. Wow, these things look cool! Also, went over to my buddies house and busted out the dye grinder on the plenum. I wanted to open up the throttle bores and the ports. The wall behind the throttle bores have already been worked but I wanted to enlarge the diameter of the bores. The stock bore diameter is kinda small. After a little grinding I believe I opened them up about 2-3mm. Also, if you've seen the runner ports on a stock plenum some of them a not perfectly round and have some bad edges. Took care of that with a little grinding too. Afterwards we decided to do some polishing. Me and my buddy took after the top part of the plenum, being it was the easiest to polish. Used a DA sander and started with a #80 grit paper. This took the longest because of all the pits in the aluminum. Anyhow, on to the #160 paper. We really went over it good with this paper in order to get all the scratches from the #80 paper. Then came the #320 paper. You could really see HUGE difference by this point. Went over it very well also. Next, #400 paper. While my friend was looking for some #600 paper he said use this for a few minutes. I used this until he found some. Alright, found some #600 and really went over everything well. Getting close but still not there! Next, I hand sanded in a straight pattern with a #1000 grit. Wow, shining a little now. Then, I went perpendicular with the same grit. And now for the last of the sanding, I used a #2000 grit. Again going perpendicular with the last work. Finally, it was getting late and decided to head home. I got out the Mothers aluminum polish and hand buffed it a little. Talk about shining now, oh man!
WEEK 5
Finally ordered my computer(#1227730). This is for the 90-92 speed density TPI. I also painted the stock runners. I used some high heat aluminum paint and it really looks good. It coats very well and is thick to make a smooth finish. Much easier to paint than polish! I also painted the lines on the plenum with teal green touch up paint to match my car color. It didn't come out like I had expected but it looks good. (See above pic.) Also finished porting the base. It really isn't a full port job but every little bit helps. I'm also checking on a fuel pump which will be externally mounted because I really don't want to drop the gas tank. So far the total bill minus the billet accessories = $370 bucks. Only thing left to buy is the fuel pump!
WEEK 6
Picked up my computer from Thunder Racing.....and that is about all. I would start tearing my car apart but I don't have a garage or shop to do this. Also, I need to get a fuel pump. I am now thinking about getting an internal pump instead of external. Suggestions welcome.
WEEK 7
OK, finally decided to tear her majesty down. I was actually gonna just swap out the vette aluminum heads I picked up but after getting down to the bare block and looking over the harness I decided to do it. I had first called and talked to Howell Engineering to get some questions answered. This company really knows there stuff. They do many conversions and can turn any ole wiring harness into whatever you want. I decided to use my stock TBI harness and let them rewire it to accept the TPI, but I will still have all the functions of diagnostics, gauges, etc. This was my biggest concern. I wanted it to be just like it was factory installed. And it will be. The first thing I had to do was pull out the TBI harness. Really not hard at all when you have the whole top end of the motor removed. I just basically started to unplug everything from the engine and tranny and whatever else. However, I did not need to pull out the harness for the lights and couple other things(forgot which ones exactly). Then the worst part was the harness coming off the computer had to be pulled through the fender well. It wouldn't have been that hard except for one of those damn plastic loom holders was anchored inside the fender. There was absolutely know way of getting to it. After finally jerking on it a while(that sounds funky doesn't it) the plastic piece stretched a little and I was able to get a knife in there and cut it. That's it. Only took about 20 minutes or so to get the whole harness out. Boxed it all up and shipped it off. Howell charges $350 bucks to convert the harness and will take a week turn around to rewire it, but I really think it is well worth it. The harness will be just like plug and play. Every sensor will be labeled and it is just a matter of putting it back in the car but install the TPI instead of the TBI. I am so excited about this. I am really glad I decided to do the swap now. I really think that if I wouldn't have done the swap while she was torn down I prolly would never have swapped in the TPI. So, I am a happy camper and cannot wait to get the harness back and to see what kind of difference there is by going TPI. I will have the vette heads on there also which should account for some gain but I am thinking the TPI will produce much more torque over all the rpms plus it will make a little more hp. Oh, I almost forgot to mention that I need to get some braided steel fuel lines made up to connect the front of the TPI to the end of the rubber lines right by the power steering. The fuel lines of the TBI run along the intake and back behind the TB, where as the TPI connects to the front. Also, I ordered a stock replacement intank fuel pump to replace the low pressure TBI pump. This pump should hold me out for a long time. I can always add an external pump if I ever make some serious hp.
WEEK 7
Still waiting for Howell to finish the rewiring of my harness. It should be ready in a couple more days and I should receive it next week. Also, Matt at Howell told me today that the chip will be customized to my application. It is not just a stock replacement chip. It will have an aggressive spark/fuel curve and timing control. Plus the chip will also delete my VATS(Vehicle Anti Theft System). I can always hook up a switch to the MSD box if I feel the need. Matt also told me to purchase a new knock sensor because there is a difference b/w the TBI and the TPI sensor. Dunno if this is true or not, but I followed his suggestion anyway. Also received my fuel pump and bought some steel braided lines. I am really not looking forward to this part of the swap. It isn't going to be easy to change the pump. Afterall, I need to lower the axle and maybe even have to remove the exhaust just to get the fuel tank out. ARGH! Oh well! Gotta do what I gotta do!!! I now need to get a TPS sensor and knock sensor and that should complete all the parts needed for the swap.
WEEK 8
Finally received my harness and immediately started installing it. Everything was going just fine until I noticed some of the wires had been moved to the wrong place. What the fuck!! My fan switch had been wired behind the alternator. Also, there are 2 red starter wires that were routed behind the alt. This is crap. I called up Matt at Howell and wanted some answers. Well, he had none. He said he was trying to follow a truck diagram or something. I have a Camaro, not a truck. I told him the starter and fan switch wires should have never been touched. Anyhow, they apologized and that was about it. So, I had to sort of do a rewire myself. Can you say PISSED! I just spent $350 bucks and this is what I get. I also received my TPS and knock sensor. Anyway, finished installing the intake parts, along with plugs and wires, fuel lines and few other parts. Bolts, wires, lines and whatever else were checked and double checked to make sure they were OK. Getting closer!!! Next week is the Fuel pump.
WEEK 9
Today is the day! After the install of the pump it should be ready for fire. So, me and my buddy took after this difficult task. First, removed the panhard rod, track bar, shocks, endlinks and few others and lowered the axle as far as possible. Ended up having to break the lines on the brakes to let the axle hang even lower. Unbolted all the exhaust, removed the passenger side rear wheel for even more clearance. With all this removed, the tank came right on out. It took a little pulling and pushing but it came out ok. Next, removed the fuel assembly from the tank and changed the pump. After this we reinstalled the assembly, and then the tank. Bolted everything back up, checked the lines, bleeded the brakes since we had to break the line, and also went ahead and changed the fuel filter. Again, checked out everything and made sure it was ready. A OK!!! Bolted the battery back up and checked to see if there was fuel pressure. Woohoo! Got pressure. Next, installed distributor cap, ran the plug wires, checked the fuel lines and injectors for leaks and anything else. Again, OK! She is ready for fire. Gave it a try and it wouldn't start. To make a long story short the car wouldn't start for shit. It ended up being the injectors were fried. Only 3 were firing. So, my buddy loaned me his that came off his rustang. After that, the car started up and ran great. Checked the timing, fuel lines and injectors again. Checked the fuel tank for leaks and everything else and they were all OK! YAHOOOOO, SHE RUNS! Thank you Jesus!! And that completes the swap. Hope you enjoyed!
