Matt Ledbetter's Twincharger Project


I'm thinking of duplicating and marketing my twincharger kit. I'm trying to get an idea on the number of interested parties.

Would include:
All mandrel bent pipes
Exhaust manifold
Blow-off Valve
Spearco Liquid-to-air IC (W/radiator and pump)
H3 Turbo
Electronics to disengage SC at boost
Pump to open SC bypass at boost
Possibly exhaust

Would not include engine management system! This part would be up to you. The exhaust system may be included, but considering the difference in personal preference, may be left up to the individual. The stock motor will probably support 300HP. The stock fuel system will not!

I would initially be shooting for a price between 2 and 3k. I know that is a big window, but I am still working out all the expenses. I will try to include everything needed, clamps, etc...

Please email me if you may be interested and I will put you on a mailing list to receive updates on the status.



I thought I would send out a quick update, as I have had the car for a month and haven't made much progress.

I managed to get the stock vaccum pump running full time. It is now used to open the bypass valve around the SC. This will allow the turbo to produce a little more boost, as flow does not entirely move thru the SC.

I still haven't cranked up the boost, but I'll be doing that tomorrow. I'm a little worried about my wastegate. I had disconnected the hose from the wastegate, capped it, and still had no extra boost. I figured my boost would have sky-rocketed. I'll up it tomorrow by turning the actuator rod.

I ordered some Dynamat Super today. Just enough to cover the firewall. It is rather expensive, $75 for 12 sq ft, but is pretty impressive at eliminating in-cabin noise levels. The car is just way too loud inside, but hopefully this will help a lot.

If I get the boost up tomorrow, I'll make a trip to the track tomorrow night. I'll send another update after that.




Well, my TCed was beaten up today by a couple of 1200lb elk. I was south of Flagstaff, at about 6:30 pm,  cruising at about 65mph when 3 elk happened to stand in my lane. I clipped one with the right side, busting up my bumber, ground effects, quarter panel, door, mirror, etc, before he managed to stick his big 'ole elk head thru my windshield spraying me with glass. The other one was already dead, or sleeping in the road, I ramped over him. The third one got away.

A couple grand, easy, in damage.

Needless to say, the car is off the market for a while. Maybe for good.


The car is in the shop. Should be done next Friday. Ended up being a little over 2k in damage. Not too shabby.

RC Engineering agreed to exchange my 650cc injectors for a set of 500 or 550s. Plus, they said they would give me the difference in price back. Nice guys over there. With the 500's, or maybe even the 550's, I should be able to get it to idle correctly. With the 650's, it wouldn't idle below 1200-1300, and had a bit of a bounce to the idle. Just to much injector for a 4 cyl 1.6.

I stopped by a place today in Tempe, Apex motorsports. I think they have had a couple of cars in Turbo, and SCC. Anyways, I'm probably going to have them install an HKS racing bypass valve to divert all the air around the SC at boost. I was trying to leave the SC on and pump and thru it, but it just made too much heat.

So thats my story, and I'm sticking to it.



I haven't received a message since last night, so this probably won't even make it to the digest.

I have been talking with a few people on the list about Sced intercooler efficiency. I just got my car back, after the "elk
incident" and figured I would run a few tests. First off, here are some numbers from David Kucharczyk's article on MR2.COM.

Copy and paste follows...

Actual outlet temperatures were as follows with an outside air temperature of 59 degrees F.

Partial throttle cruise at 70MPH (SC engaged, 8" vacuum)         100 F
Partial throttle cruise at 70MPH after full boost run            130 F
Idle, engine compartment fan on.                                 100 F
Maximum observed outlet temperature (long uphill run, 10 PSI)   200 F

Now, here are the numbers I got. This is with a twincharger setup (turbo in series with SC), 23 PSI, and a Spearco liquid to air intercooler.

Outside temp - ~75

Partial throttle cruise at 70MPH (SC engaged, roughly 8 inches of vacuum) = 80 F
Partial throttle cruise at 70mph after full boost run = 87-88 F (dropped quickly...)
Maximum observed outlet temp (Extended high boost runs, 23 PSI max) = 93 Degrees

This is with leaving the SC on. Sooner or later, I will install another bypass valve to divert air around the SC, and I will be able to shut off the SC and let the turbo make all the power. This should lower temp's as the SC creates more heat.

I would say that this shows the stock setup (at only 10lbs of boost) leaves a little something to be desired. I would be interested in seeing the numbers on a good air-air setup.

'88 Twincharged


I found out some interesting things tonight. I went and picked up my car from MR2PP and took it out for a little spin. I drove for 5 or 6 minutes and noticed it was getting pretty hot. My intake air temp was hitting almost 200. We traced it to a blown fuse for my liquid-air intercooler pump. Replaced the fuse, went out and drove around again and the intake air temp dropped down to the normal mid 90's. So... not the way I had intended on proving the efficiency, but it achieves the same reults. So, I am seeing a drop of a little over 100 degree's after hard runs at 20psi.

I've also found that BOV's on my car do not make the normal sounds.... At the Mobile meet, Brian had mentioned that my HKS sequential valve didn't sound the same as other valves he had heard. Well, I replaced it with a ZEN BOV and it sounds almost the same. Sounds like a burp.... makes the same sound even if I don't have the hose hooked up for manifold pressure. Anyone have any ideas? I know it is working as I can rev the car up, while standing outside, and feel it release air as I let off the throttle. One of the many things that confuses me...

MR2PP also installed the J&S ignition system for me. He was able to advance the timing a bit and I seem to get a little quicker acceleration. I also noticed an increase in mpg's on my way home. I got a tad over 30mpg's, but that was at a cruising speed of 65 (My girlfriend was following in my Tercel wagon, so I had to wait up...)

I also have a cat on it now and it seemed to quiet it down. I didn't notice any increase in spool-up time.

I have a Blitz Dual EBC on the way and then I'll be able to play with boost a bit. I'll get it to the track in the next couple of weeks. After all this, I'm still considering selling it. If anyone is SERIOUSLY interested, please drop me a note.

'88 Twincharged


This is one of the things I have offered to do in the past. I had wanted to wait until my car was running almost perfectly. I seem to be getting closer....

I do see a few problems though. I could have the pipes, exhaust manifold, and exhaust duplicated. Although, this would almost limit the buyer to using the exact setup I have. The turbo to SC pipe doesn't have much freeplay and I would hate for someone to buy it from me and then have it be off by an inch or so.  Getting the exhaust manifold made would be tricky also. It would need to be almost an exact duplicate of mine as the turbo would need to hang in the same spot or everything would be off. The intercooler would be the same situation, as I don't think the stock intercooler would work with the pipes I have. I used a generic Spearco core and had the end tanks welded on, so it wouldn't be the easiest thing to duplicate.

So, I think it could be done, but it would be far from a "bolt-on" package. I can't risk any $$$ for this project and I would be losing my car for a good amount of time. If there are enough people interested, who would be willing to front a little cash, we can pursue it. There would be some risk involved and I would be in no position to refund any money if
we can't get things to bolt up.

So, consider the possibilities and let me know....

BTW. mine is not the HKS kit.... although the setup is basically the same.

'88 Twincharged


Well, there seems to be a great amount of interest in the Spearco liquid-air setup. Don't be offended if I don't reply to you individually, as I have received about 20 emails already. I'm still working on getting a better deal, but the 10% is the best I have found.

Jeff and others....

I'm using a Perma-Cool radiator up front. I believe it is actually an oil cooler, but does the job well. It is rather large, probably 4" thick, 10" tall, and 12" wide. The good thing about having the radiator in the front, is some of the heat will be lost in travelling the route from the back, to the front, and then back to the heat exchanger. I have heard that the best thing to use is a radiator from a home AC unit, although I haven't tried it. You can probably pick up a used one from any home heating/cooling company. I've seen places that have piles of them sitting outside. Just make sure it doesn't leak. The disadvantage in using an air-air unit in the MR2 is (In my opinion) it heat soaks rather quickly. Following is a qoute from David's tech article on MR2.COM, anyone with a sc'ed 2 should really read it...

Partial throttle cruise at 70MPH (SC engaged, 8" vacuum)         100 F
Partial throttle cruise at 70MPH after full boost run               130 F
Idle, engine compartment fan on.                                     100 F
Maximum observed outlet temperature (long uphill run, 10 PSI)   200 F

Now, the number that gets me is the 200 F on the "long uphill run, 10psi". Considering I saw around 210 degree's when the fuse to my pump was out, I feel pretty safe in assuming that the stock SC'ed IC does almost nothing after a short run with boost. Mine was also measured at 21psi, as opposed to the 10psi from David's car. This leads me to believe that the IC may warm up to the point, that not only is it no longer cooling the air, it may actually warm it up a bit. After shutting down after a hard run, my heat exchanger will heat-soak a bit. If you put your hand on the side of the Spearco unit and start the car, you can almost instantly feel the outside of the exchanger cool down.

I'm sure I sound like a broken record, but I'll give you some of the numbers I have seen. The intake air temp doesn't vary much from cruising to idle. It normally sits in the high 80's, when the outside temp is around 70. After driving in the mountains (lot's of boost coming out of the corners) in AZ, with an outside temp of over 80, my temp's were in the low 100's. Before letting it cool down, I made a run from 0-130ish, and the temps rose to about 110. At the IMOC gathering in Denver, I was in the boost for probably close to 45 minutes. Someone who attended the meet can give us a better estimate on the time. I kept a good eye on my temps, as the fuse had blown the day before, and never saw anything much
over 110 (I think it hit 112 for a second).

I'm not sure what else I can say on the efficiency factor. All of these temps were taken from my SDS engine management system. One thing I was told, is be sure to use a good pump. Don't try to save a few bucks by using a generic pump as you don't want it to go out. I can get the brand and model off of mine later today. On the MK1 Sc'ed, I would suggest
trying to mount the radiator up front. I have seen no drawbacks to blocking some of the flow to the stock radiator. For the mkii, mounting it in front of the vent may be a good choice, although I think you would see lower temps if you mount it up front. I'm using a combo of 40% water, 40% anti-freeze, and 20% Redline WaterWetter.

The Spearco unit's come with standard inlet and outlet sizes of 3". They will attach smaller size inlets/outlets for about 90 bucks. I would suggest using some type of a couple that converts the 3" pipe to whatever size you need, if you are trying to save a few bucks. I believe they will also set up almost any end-tank configuration, as long as you send them the measurements. If someone sends them stock IC, I'm pretty sure they would be able to fabricate something that would drop right in (if you want to leave it in the same location as stock, obviously), although you will most likely need to fabricate some brackets.

I don't have a current catalog, so I cna not give out the exact dimensions. I believe Chris Conlon has a current catalong so maybe he will be kind enough to list the different models, dimensions, and list prices. I believe they have 4 standard liquid/air heat exchangers.

And to the few who asked me what my "cut" is.... I'm not getting anything out of this, just trying to promote what I think is a great product. Now, back to my job here at Spearco..... just kidding....

Any questions I missed or any new questions, just drop me a note.

'88 twincharged


  I'm getting my HKS bypass valve mounted today. I finally got sick of running the Sc'er and turbo in series, so I'm moving the bypass valve to after the throttle plate. It was a pain to get everything out of the car, but I finally did it. I'm mounting the bypass valve on the pipe that connects the throttle body to the Supercharger. This will get rid of the wide-open throttle problem I had before when the valve opened and diverted air around the throttle plate. I did run turbo only for a while and 15lbs from the turbo feels quicker than the 22lbs of combined boost I was running before. I plan to run 14-15lbs on the street and around 25lbs on the track. I plan on having it back together by Thursday and I'll make a trip to the track on Friday night.

'88 twincharged

7/11/98 - Bypass Valve Install

Well, as usual, nothing went as planned... I got the throttle body to Sc'er pipe back from the shop and I went to put it all back together. Of course, the bypass valve does not fit... So, I have 2 choices. I can go back to the same shop and have them "turn" the flange they welded to mount the valve(and it still might not fit). I wanted to mount the valve right off of the TB 2 Sc'er pipe, but it doesn't look like it is going to happen. So, my 2nd option.... is to run a small pipe from the flange I had welded on to the TB to sc'er pipe. Then mount the bypass valve on the end of the pipe. Not the prettiest way to do it, but I think it is the only way. So, I'm ordering 2 more flanges from CAP. I'll have a small length (1" or so) of 1-1/2" steel pipe welded on to each flange. Then one will bolt to the flange on the bypass valve and one will bolt to the flange I already had welded on to the TB to Sc'er pipe.

Is anyone still with me?

Then it will be a couple of 90's, a couple inches of pipe, and maybe a 45 to connect the 2.

To sum up my rambling.... Instead of mounting the bypass valve right on the pipe, as I had wanted. I will have to run about one foot total of pipe and then mount the valve. Shouldn't make much of a difference.

So, if I'm lucky, everything might be back together next weekend. For now, I'm stuck in the Tercel.

'88 twincharged