Performance chip

[DAVES89]

I PM'd a couple of guys here on the forum regarding a performance chip. I want to add horsepower [20 or so] but I don't want to do the turbo/supercharger route. A friend of mine installed one in his diesel powered Ford Excursion and has been very happy with the results. He now has about 320,000 miles on it after putting the chip in at about 100,000. He thought that might be a way for me to go.

Anyone have opinions?

[Guest Craig57]

Dave My Wisconsin mentor. I bow to yo like Aerosmith/DMC ! "WALK THIS WAY" I follow in your footsteps...Please advice. Dave, You kill me. In a good way!

[DAVES89]

"Follow me I'm the Pied Piper, trust in me, I'm the Pied Piper and I'll show you the way"... lol

[2seater]

I don't think you will see a 20hp increase with only a chip. I have had many chips done, most are for the turbo installation, but I did have two premium fuel chips for N/A use (one was from Fastchips and the other from Ryan @ GMTuners). It can help keep the engine cooler (thermostat and fan engagement), which can help performance a small amount, but it does cost a little in fuel mileage. Another item I had done in the chip was to prevent converter lockup until a chosen speed is reached, such as 50-60 mph. It doesn't have a direct horsepower impact, but it keeps the engine at an elevated rpm when running below highway speed which sharpens throttle response. Open up the exhaust and a free flow intake as well to get the most from what you have. I use the maximum MAF reading to establish a baseline and to see if any changes have improved air flow through the engine. Ambiant weather conditions need to be similar. Use 1.32 x air flow in grams for approx. hp level. A diesel is a different animal when it comes to tweaking the fueling and can't be directly compared to a gasoline engine

[DAVES89]

2 Seater, seeing as you are here in the Fox Valley, you will relate to what I am about to say. The reason why I am interested in adding a bit more punch is not to race anyone, it is just for the clowns out there that want to pass everyone in sight, then cut in to take the exit to 441 off of 41 or College off of 41. I guess what I will do is nothing... other then manually down shift to a lower gear in those parts of town.

Otherwise car has enough zip for me [never thought I would say that after some of the cars I had in my youth].

But I will keep in mind your suggestions.

[2seater]

Ha Ha Haa! Yes, I understand completely but we don't have a monopoly on that sort of driving. I don't think the chip is useless, but some benefits are not in the pure hp. realm. I should qualify the change in lockup mode. It doesn't prevent the transaxle from going into fourth gear, that's a hydraulic function on the '88-'90, so the low load rpm is similar, but it allows the engine to rev more freely for the transient response you refer to.

[padgett]

Only way to get more hp from a "C" 3800 without boost is with NO2. The whole system (intake, cam, exhaust) is limited.

[NCReatta]

Only way to get more hp from a "C" 3800 without boost is with NO2. The whole system (intake, cam, exhaust) is limited.

Challenge accepted. :cool:

[D-a-n-i-e-l]

I would start with the intake. I think (have not tested/checked) that the later manifolds (up to 94) would improve intake air by a lot. Second you need to free up the exhaust a little bit. After that you could get a chip done that might get your 20hp

[2seater]

I do not know if a later model Series I plastic snakes (AKA Tuned Port) manifold will fit or not. I do know the aluminum version will fit, with small modification to the head (drill two holes for the PCV system). I have tested the air flow through the aluminum TPI and it does not flow appreciably more air, however, the tuning of the intake runners is vastly different. The long runners are designed to help the low and midrange performance. I suspect the plastic version will flow more air with larger and smoother runners. The short runners of the vin C manifold would generally be to help high rpm performance, sort of an oxymoron. The one item the aluminum manifold does not have is EGR. It would have to be programmed out in the chip, or find a creative way to add it. I have been pondering on how to add it to the one I have as I plan to add it to my spare engine when it is reassembled.

[DAVES89]

This is an interesting series of posts, thanks for your inputs.

It looks like a trip to Gibson's is in order to take a look at cars with plastic plenums.

Is/has there been a problem with them warping/cracking?

Does this plenum allow for the EGR valve?

Do I just look for cars with a "C" motor? Or just look for a 3.8?

What size exhaust do I use?

Do I keep the same exhaust manifolds?

Would I use an air filtering set up similar to the one in 2seaters picture?

Would a chip that locks up overdrive say at 60MPH sound about right?

Any other recomended "upgrades" to the chip advised?

I am not sure I am going to proced with this, but I certainly am interested.

One of the reasons I brought this question up is that while we all enjoy are cars, I am sure that we all wish there was just a bit more throttle response without running the risk of blowing a tranny [which from reading posts from others who have done the Supercharger upgrade has had happen].

Just want to be able to put my foot in it and feel more then I am getting.

[2seater]

I cannot say from hands on experience, but the vin C engines ended in the early 90's as the "L" engines were phased in. Some car lines used it later than others, but I do not believe there were any "C" engines with the Tuned Port style manifolds. The Series I, vin L should all have the TPI style intake manifolds and since the basic configuration is the same as ours, the intakes should be able to bolt up. Series II, '96 and later, are a different configuration. I "think" GM installed EGR on the plastic TPI manifolds and there have been stories about the EGR passage leaking but there are kits available to repair. I am pretty certain the EGR operating system is different than the C engines, but if the provision is at least accessible, I would guess our style EGR could be adapted to it? I do not know if the exhaust manifolds are more efficient or better designed, or even if they would fit. The exhaust probably has a different connection for the EGR if used. The stock C manifolds flow reasonably well, and the outlet area can be improved. At the least, the restriction can be removed or it can be cut and welded into a tapered funnel configuration. Careful measurements would tell. Personally I am still running the stock 2.25" system even turbocharged, but a 2.5" system would seem to be a useful upgrade, with no empirical evidence to back it up. The cone style filter offers more filtering area, and lower restriction. Except for full throttle operation, the stock system probably isn't a big restriction but it certainly sounds more powerful I have a lockup delay harness that prevents TCC engagement unless in fourth gear. Generally with everything else stock, it will lockup @ around 50 mph at minimum throttle. You can try it if you would like just to see if it is something you would like to incorporate in a chip. It just plugs in between the harness and connector at the front of the trans. I used to run my engine at 160*F for detonation resistance with the turbo install but it does cost fuel mileage. Padgetts suggestion of 180* seems like a good compromise, with fan programs changed to match. My ancient testing from many years ago showed the acceleration to be best around 140* engine temperature but it isn't practical for a daily driver.

[DAVES89]

I went on line to look for an aftermarket intake for the "C" motor. There is none. I will go out to Gibson's and look at the "L" motor you refer to. I will check for the EGR as you said. Regarding the EGR bolting up, do you think a EGR mounting plate adapter might work? [i have a good friend who is a machinist]

As an additional question, would mounting the EGR from the "L" motor not be compatable with our system?

I don't want to make this too complicated as my fear is that should I have drivability issues later, the question in the back of my mind is "Is it because of the change I made or something else?"

[2seater]

As far as I know, the operating system for later models with EGR is different. From the way I have heard it described, it is a single valve which is variable in nature where the C engine uses three discreet pintle valves with different size passages to vary the amount of EGR. I am not a programmer so I don't know if this hurdle could be overcome. I would doubt it. For some period of time, GM did not incorporate EGR at all, the aluminum TPI model is one example. The C engine is a two piece assembly with all of the passages in the base plate, but wether this can be adapted or not is unknown without a close examination. Perhaps someone with a later model may have an idea?

[padgett]

GM refers to them as "digital" (three valve) or "analog" single valve. FWIW my '92 TranSport "L" has no EGR atol.

[DAVES89]

GM refers to them as "digital" (three valve) or "analog" single valve. FWIW my '92 TranSport "L" has no EGR atol.

In my search of aftermarket intake manifolds all that was available was the manifold for the "L" motor. The engine w/o the EGR.

[2seater]

I don't know of a plug and play manifold for the C engine either. Anything to be adapted would require some work. Elimination of the EGR function would be a programming issue which I am pretty sure some of the S/C guys have faced. It would certainly seem to be the simplest solution. It will certainly work and run without it. The benefits, or not, of EGR can be debated but even in the modern era, it appears the OEM did it both ways.

The aluminum TPI manifold will bolt on. The fuel line connections are both at the drivers side rear of the manifold so the fuel lines would need to be rerouted/modified or replaced. The fuel fitting size and thread are the same. The fuel injectors are the same size as the C engine. The thermostat housing is different and will require a different upper radiator hose. The steel line for the heater from the manifold is similar and the stock one can be modified or get the one that comes with the L. The connections for the TPS, MAF and IAC all plug in. The MAF uses the same frequency range as the C engine, and looks the same on the oustide, but is different where it inserts into the housing. The throttle, cruise and trans. detent cables all connect the same. To get the benefits of the L integrated PCV system one hole would need to be drilled in each head, or, an external system would need to be added. The L intake gaskets locate the hole required.

[padgett]

Are you certain ? I thought the "L" used higher flow injectors (28 ppm ?) than the "C". Also MAF flow is imited to 170 gm/sec in the "C". Finally the throlle body is about 30% larger in the "L". How that affects the MAF reading I do not know.

[2seater]

I am only certain about the aluminum TPI manifold that I have in hand. The throttle blade is the same size as the one on the vin C. The vin C uses two discrete units, one for the throttle and the other for the MAF. The TPI has a one piece integrated throttle/MAF casting. I have actually adapted the TPI assembly to the C manifold and have used it in both N/A and turbo configurations. I used it for a the location of the IAC, not for any flow advantage. It gave me more room to route the turbo exhaust outlet below the throttle body. I do have a stock C throttle body that was modified many years ago by a guy on the Grand National forum. It is 2mm-3mm larger in diameter along with a new throttle blade, and it does flow more air. I have not looked at one, but the assembly on the L27 supercharged engines looks similar and may be larger?? The injectors I removed from the TPI manifold are Bosch 917's (last three digits) with a rated flow of 18.27#/hr. The stock C injectors I have are 901's with a rated flow of 18.55#/hr.

I am sure that you are correct that there are larger throttle and injector combinations out there, but they are not part of the assembly I have. The only way to know for sure would be to remove the throttle and measure the opening at the blade and check the injector part numbers. I agree that the 170 gr/sec is due to the combination of MAF and chart in the ECM that reads it. I have flow tested both style MAF's to compare the actual CFM flow vs frequency output from the MAF and the stock C unit is almost a mirror image of the TPI one I have. IMHO the TPI manifold isn't a hi-horsepower manifold, but is designed to enhance the low and mid-range performance where the engine spends the majority of its time. The runners are actually quite small and vastly longer than the C manifold. I would imagine the newer TPI style manifold, a sort of curled up tunnel ram, particularly the plastic versions, have larger and smoother runners to aid the high speed performance.

On an old, but related subject: I have always been curious what the maximum MAF readings are on some of the modified engines out there, particularly the Series I S/C engine swaps. About ten years ago I did get a couple of replies on the bone stock cars of 125-130 gr/sec. At that time I was seeing 137-138 on my engine: chipped, ported heads, larger T/B, exhaust restriction removed, no cat and cone air filter. Now, my bone stock original engine with the 1988 cam, cone filter, replacement cat. and straight through muffler shows 142 gr/sec, and 172 with 4-5 psi of boost. Model year, ambiant weather conditions and any modifications are important.

[DAVES89]

I had gotten the Red out about a week ago and today was the first day I really drove it since storing it. One of the things I noticed was that the Red accelerated much better then the Black w/o hesitation at speeds between 45-65 MPH. I started thinking on that, and remembered that my old neighbor, who runs a transmission shop, took a look at the Red when I complained that I was having a 1st-2nd gear shifting issue at WOT. At any rate after I got it back, he stated that he had done a few things to make the tranny a bit more "aggressive." He only charged me $100.00 so he probably didn't spend to much time on it. I know he did not switch out the Trans shift modulator, it is still a G.M. unit.

However he does drag race cars, and rebuilds auto transmissions so he probably knows a trick or two...

If he can do to the Black what he did for the Red I will be happy.

[KDirk]

Dave,

If he does some "magic" to the trans on the black car, please find out what he is tweaking as I would be interested in knowing - if it isn't too much trouble.

KDirk

[jonlabree]

You could change the fluid to "F" type, for sharper and ouicker shifts.

[Guest nomad]

Nothing worked better than installing a shift kit. Better 0-60 and less stress on the trans. But i did go thru 4 axle half shafts.

(300,000 miles and counting). Opps..... jinx...?

[DAVES89]

Dave,

If he does some "magic" to the trans on the black car, please find out what he is tweaking as I would be interested in knowing - if it isn't too much trouble.

KDirk

I should be having lunch with him this week. I will keep you posted...

[DAVES89]

I spoke to him today and he said that all he did was make sure that there was no "slop" in the accelerator cable. So that is the first thing. As a dragster he said that if I did not want to buy a performance chip he thought by taking out the oxygen temp.sensor and reading it warm and then again after putting it in a refrigerator for 5-6 hours to compare the resistance difference, then going to Radio Shack to get a resistor to wire in. He said this would make the car "think" that it was still cold and would bump the fuel in the air/fuel ratio and get you a little more kick. He said this would be a "poor man's performance chip".

He also said that I might have to do the same thing with the water temp.sensor [if there was a seperate one to talk to the ECM.

What do you think?

[D-a-n-i-e-l]

that will deliver more fuel, does not mean more power, you are looking for a good fuel air mixture for more power.