Sprintex / Boostec Supercharger Install

Yes I finally pulled the trigger and did this.

Pre-Install- '98 XJ with 165,000 miles, compression tested to 165-170, installed new fuel pump/pressure regulator, seafoamed, new water pump, high flow cat and 2.5" magnaflow muffler and tubing, 62mm TB, upgraded ignition- coil, cap, wires, rotor, new plugs, new O2 sensors, and 703 injectors, Innovate wideband O2 sensor and gauge.

Parts- Initally bought a Banks revolver header but the #6 tube hit the s/c manifold. Found a ceramic coated Gibson SS header on Amazon which fit with 1/2"+ clearence on all pipes and manifold. Boost gauge and cool intercooler gauge with 2 sensors for pre and post temps, Sprintex S/C kit with AEM FIC-6 controller.

Install- After much reading and debating I did wrap the headers with header wrap and stuck on the Gold heat reflective barrier to the bottom of the new s/c intake manifold. I drilled and tapped 2 additional holes in the TB plenum for pre'supercharger temp sensor and a possible methanol injection and drilled the intake manifold for a boost gauge and the post supercharger temp sensor. The disassembly and install is very straight forward. No surprises. Just unbolt intake and exhaust and then reinstall the exhaust and new intake and supercharger.

The Good- It all fit as supplied. It started right up.

The Bad- the throttle cable bracket was too tall for my liking and I had to modify it to shorten the height. The bolt heads holding the new idler tensioner brachet were too thick and hit the belt and had to be ground down for clearence. The Volant CAI that I had now didn't fit because the s/c mounts the TB slightly higher and the Volant would not clear the hood so I had to buy a temporary air filter and crank case filter to fit.

Question, why does YOUR install look exactly like bpas328xi's. Heck, even your photos are from his photobucket account. Since he's claiming it's his SC on CF how can you claim it's yours on naxja?

Started right up but had a fast idle of 2000rpm. Broke a plasctic pintle cap on one of the injectors and had to get another 703 injector. Found the cause of the fast idly, I forgot to install one of the plugs in the hole I drilled and tapped for the boost gauge line. A 1/4" hole can suck a lot of air and be quite a leak. Plugged and now idles normally.

No AEM wired yet. Did drive it around keeping it out of boost to get some of the 87-89 octane fuel out of it and check for leaks. I runs great. It has a different sound to it. It revs much easier and much smoother. I think that it is a combination of the new short runner s/c intake manifold and the Gibson headers. Definately more power off boost.

Ordered some new pieces to make a Spectre like cowl CAI. Can't use the Spectre directly because of the new slightly forward and higher TB location.

In the next few days I will install the wideband, boost and temp gauges in an A piller pod, and install the AEM and program it. Then let it get boost! Next week will probably take it to a local dyno/tuner and have the AEM tuned on the dyno and get some dyno readouts of it.

More to come soon...

Thanks, remember father and son deal here. It's ours.

One of the first things that I notced when test driving it is that the water temp is slightly lower. Before it would be slightly above the 210 mark and now it iss slighltly below it. I will get out the scan tool and read it off the OBD and see just what it is. I think that this is because of the ceramic coated headers, the header wrap and the reflective gold barrier under the intaake manifold and the much smaller/shorter s/c intake manifold and less head sinking and absorbing of the exhaust heat.
So far, the measures to block some of the header heat on this non-crossflow engine seems to be working. More testing.

CobraMarty said:

Thanks, remember father and son deal here. It's ours.

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Wait. So I was arguing with a father/son duo in that twinkle bulb thread? Which of you is supposed to be the mature one?

Anywho, congrats on the purchase, and best of luck with the tune.

cobramarty, i've been waiting for a writeup like this, can you give more details please about the kit cost, components, etc,

I'm specifically interested in the fuelling, how are you supplying the extra fuel , is it something in the kit or are you using an external piggyback like the AEM?

more details also about the driving experience, how much more is it putting now?

I believe he's using an AEM along with a 7th injector which is a terrible combination. He was much better off with 6 high-flow injectors along with that piggyback.

urban yan said:

I believe he's using an AEM along with a 7th injector which is a terrible combination. He was much better off with 6 high-flow injectors along with that piggyback.

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Thanks for making that clear.

Yes it uses a 7th injector controlled by the AEM FIC-6 which also controlls the ignition. This is a great way to go with this low boost application. When out of boost the engine runs off the stock ecu programming and when under boost the AEM will turn on the 7th injector proportional ot boost and retard the timing also proportional to boost.

The additional injector and controller has been used in the turbo/supercharger world for over 20 years and is well proven. In twin screw superchargers like Whipple, They have been using additional injectors pre supercharger from their beginning. The additional injectors will handle all the feuling needs required of boosted engines. In addition the fuel will provide a liquid cooling effect and lower the intake charge temps. That is why I installed the dual temp gauge to measure this effect.

The disadvantage of using the 6 larger injectors is ther is NO cooling effect from the fuel as it is injected right at the intake port of the engine. The 7th injector will cool the supercharger and the air it compressed and in the 7th injector system the intake charge air WILL be lower temp than the 6 larger injector setup. I could have done the 6 bigger injectors which is what i did do with my centrifugal supercharged F150 but on this twin screw application I wanted to do it differently with the 7th injector.

CobraMarty said:

Thanks for making that clear.

Yes it uses a 7th injector controlled by the AEM FIC-6 which also controlls the ignition. This is a great way to go with this low boost application. When out of boost the engine runs off the stock ecu programming and when under boost the AEM will turn on the 7th injector proportional ot boost and retard the timing also proportional to boost.

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Is that why it took Rick 2+ years to get that 7th injector to run on that unit (only to put his malfunctioning XJ for sale on craigslist)? Is that why o-gauge-steamer is abandoning the 7th injector on his boostec? More power to you if you get that 7th injector to run properly, BUT it's not the best way to go.

mmag1982- The 7th injector and AEM FIC-6 controller is included in the kit as well as the new fuel line to connect the fuel line to the stock fuel rail and 7th injector. It is premade with nice quick connects. Very easy.

urban yan said:

Is that why it took Rick 2+ years to get that 7th injector to run on that unit (only to put his malfunctioning XJ for sale on craigslist)? Is that why o-gauge-steamer is abandoning the 7th injector on his boostec? More power to you if you get that 7th injector to run properly, BUT it's not the best way to go.

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Thank you for cluttering up this build thread, and I have no idea as to the answers to your question. Your opinion that it is not the best way to go is just that- your opinion. There are many ways to skin a cat. I have built way too many turbo and supercharged vehicles and boats to argue with you on this point. You can start your own thread on the merits of what is the best way to fuel a supercharged engine.

For everyone else interested, the 7th injector will work just fine.

cobramarty, its a real good job , sounds very interesting to me , i already have an AEM FI-6 that i didn't install yet and a running wideband afr gauge.

couple of details though:
- where did you place the extra injector, i assume somewhere where it feeds all 6 cylinders symmetrically?

- what length of drive belt did u use after the re-routing?

- any idea about the kit cost without the AEM FIC?

I don't mean to argue in any way, but The AEM FIC is way more capable to be used to run only 1 injector.
what i dont get is that the logic of tuning is you should clamp or control the o2 sensor signal somehow through the FIC so the stock PCM doesn't sense the rich AFR needed for for boost that is being added by increasing the injector pulse width by the FIC.

having that said, is the 7th injector setup following this logic ? i mean the PCM has theoretically no control whatsoever on it.
i'm concerned that the PCM would just pull back the fuel the 7th is adding by reducing the main 6 injectors?

keep us posted on your full throttle runs and your live afr readings with boost please and intake temps of course

The seventh injector works just fine as long as the electronics controlling it fires it multiple times during the cycle. If that makes sense. I walked away from the idea due to my concern over fuel distribution issues. The AEM only fires it in conjunction with which ever factory controlled injector is tapped for the fire signal. AEM recommends that the number 1 cylinder be used.

CobraMarty is keeping me in the loop, off line, as to how well distributed the fuel is. With Zero Testing having been done on the AEM F/IC Sprintex combination, I elected to be very conservative in my approach. It MUST BE NOTED that with the Perfect Power SMT8-L in place, I had ZERO fuel issues. I did have massive ignition issues with the SMT8-L which drove me to the F/IC.

An idea that Boostec lifted, from me, by the way... Figures that they would grab the incorrect part number from AEM. As long as the OP stays with the extra injector, he should not see any CEL incidents. If, however, he goes with replacement injectors, it is a near certainty, codes will be thrown.

CobraMarty said:

Thank you for cluttering up this build thread, and I have no idea as to the answers to your question. Your opinion that it is not the best way to go is just that- your opinion. There are many ways to skin a cat. I have built way too many turbo and supercharged vehicles and boats to argue with you on this point. You can start your own thread on the merits of what is the best way to fuel a supercharged engine.

For everyone else interested, the 7th injector will work just fine.

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Marty, thanks for sharing your experience, wisdom and insight on this subject.

Ignore Urban....every thread he posts in seems to turn into a who-can-whiz-farther-fest...oh, and lest anyone hasn't picked up on his opinion......Rick Rimmer is dumb. hasta

o-gauge-steamer said:

The seventh injector works just fine as long as the electronics controlling it fires it multiple times during the cycle. If that makes sense. I walked away from the idea due to my concern over fuel distribution issues. The AEM only fires it in conjunction with which ever factory controlled injector is tapped for the fire signal. AEM recommends that the number 1 cylinder be used.

CobraMarty is keeping me in the loop, off line, as to how well distributed the fuel is. With Zero Testing having been done on the AEM F/IC Sprintex combination, I elected to be very conservative in my approach. It MUST BE NOTED that with the Perfect Power SMT8-L in place, I had ZERO fuel issues. I did have massive ignition issues with the SMT8-L which drove me to the F/IC.

An idea that Boostec lifted, from me, by the way... Figures that they would grab the incorrect part number from AEM. As long as the OP stays with the extra injector, he should not see any CEL incidents. If, however, he goes with replacement injectors, it is a near certainty, codes will be thrown.

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not to bag on the whole street/performance crew for this, but do you know just how easy it'd be to make it fire once per stock injector firing?

Really easy. Like, one microcontroller, one voltage regulator, 6 signal level translators, and one MOSFET easy. Maybe 200 lines of code for the microcontroller.

All you have to do is (assuming you can't control the 7th injector pulse width from the AEM) mux all the injector drives into one injector driver signal, then use that to tell the AEM to fire. Then take the 7th injector signal from the AEM and divide its width by 6 (to compensate for the fact that you're firing 6 times instead of once, if the AEM can't be set to fire 1/6th the width) and drive the damn injector. Some of this may need to be tweaked, you guys are the motor tuning experts, not me.

Hell, if the AEM can be set to fire the appropriate width to handle it being fired 6x per cycle instead of once per cycle, all you need is some freakin' transistors and a logic chip or two. If you used CD4000 series logic you could even skip the level translators and voltage regulator.

I can't believe this much arguing has gone into this damn thing when it's such an easy problem to solve.

I appreciate forum for being here and letting me post this install information. To show my appreciation and support for , Today I have joined as a paid member. Thanks again.

CobraMarty said:

I appreciate forum for being here and letting me post this install information. To show my appreciation and support for , Today I have joined as a paid member. Thanks again.

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Thanks for Joining.

XJEEPER said:

Ignore Urban....every thread he posts in seems to turn into a who-can-whiz-farther-fest...oh, and lest anyone hasn't picked up on his opinion......Rick Rimmer is dumb. hasta

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Fakk my opinion, just google Rick's name. He's left a trail of carnage behind with his extra injector set-ups/sc kits (from land rovers to subarus).

I'm actually glad to see this thread because I want to see this unit in action. Rick claimed his kits were simple plug and play systems (for people who don't like hacking their jeeps - like CobraMarty). Did the AEM come with a patch harness? Is it properly tuned for your specific application out the box?