HuggyBear

i aquired a 1990 GXL with 110K this june(dual exhaust, and no cat. good thing it was still under safety so doesnt need to be looked at .

i was considering going the supercharger route, and was considering a non-turbo option. i was told this required an aftermarket fuel injection(because of the number of injectors?) or a switch to carburation. i was told carb would be a pain in the *** to do, so that leaves fuel injection.

if anyone has any suggestions or advice on an injection system(or some other alternative to solve the issue), or if im wasting my time on a non-turbo charger(please post reasons) i would be soooo greatful. im just getting started with this car and trying to learn as i go. im catching on a bit(i think

thanks again for any help given....

1990 GXL
dual exhaust, no cat

vaughnc

HuggyBear,

I am planning on getting a convertible as a dialy driver in addition to my 92 Turbo II (made in 91). The supercharger route is great if you just want good horsepower and more torque. There is a minor turbo upgrade, but don't think you'd want that.

My plan is to find a cheap convertible with a blown engine. I'll get a near-crate (rebuilt) engine, have it street ported, get a new ECU (engine management), either larger primary fuel injectors or secondaries that kick in ~3500 (similar to the OEM turbo setup), supercharger, and gagues to monitor it.

That should give me good fuel econonmy shifting below 3500, good power between 1500-3500 (supercharger), and a nice boost above 3500. If I do it right, it won't run lean and be tuned to run clean and only sip the gas.

HuggyBear

thanks for the reply vaughnc.

with the supercharging option, is it just that i need larger injectors? or is there somthing else that needs doing? referring here to the "aftermarket fuel injection" i was told i needed.

also, you refered to larger primary injectors OR secondaries that kick in at 3500. how would the injectors be set up on my car currently(assuming nothings been done previously)? do they all pump fuel constantly?

BTW i like the idea about the secondaries not firing till 3500. better on fuel i guess, and you still get charged on the primaries.

im still new to this stuff so thanks for replying to this

SpeedRacer

Stock, the secondary injectrors fire under full throttle at 3800rpms.

GTUsGUY

vaughnc, who manufacture the supercharger compatible with the original EFI?

Icemark

The stock primarys generally are fine up to about 200-250 HP BUT the secondaries should be replaced with at least 550s for any F/I system.

I have only found two kits that are for supercharging an N/A, one replaces the injection with a down draft Carb (not gonna work for me in CA) and the other runs around $3500+ installation, but keeps the injection. I'd do the work myself so I wasn't concerned about the cost of the install, but $3500 is still very high for a system that is not really ready for prime time.

At that price its gonna be cheaper for me to find a blown motor T2 and a Jpec motor and drop it in with a Haltech than to add the supercharger.

SuperchargedRex

The kit that was commonly known as the Nelson/Paxton sc kit uses the factory fuel injection. You can find a lot about it on my website, link is in my sig. Unfortunately, Nelson is no longer making the kit; and Mariah Motorsports has been saying for over a year that they'll do a run, but nothing yet.

As some of you know, I've been looking into reproducing the necessary custom parts for the Paxton kit, and putting together a list of all the off-the-shelf parts.

I've come to realize that besides the mounting bracket and piping to the tb, you also need their thermostat housing; the factory unit will be in the way of the mounting bracket.

Black-Clawson CNC Machining, up in Fulton, NY can reproduce the bracket and the thermostat housing. They quoted me $200 for the bracket as a one-off, $125-140 for larger orders of 25-50 pieces. (I was able to show them one of Phil Garrott's busted ones.) They have an awesome shop, and would definitely be able to reproduce the thermostat housing, but couldn't give me a price estimate without my taking it off the car to measure it.

Next on my agenda is hooking up with John at Intense Performance for the throttle body horn. I figure he can model it after the plastic one that comes with the cars. I've been thinking that I'll leave the elbow between the sc and tb horn to the individual; piping can be handled by any shop that does turbo work, you know like installing front mount intercoolers. You can buy the tubing off the shelf and cut to size.

Paxton has also sold the rights (along with all their parts and stuff) for the SN series superchargers to Craig Conley of Paradise Wheels. Apparently, Craig has been doing Paxton's support for a while. I spoke at length with Craig, he's a real nice guy interested in supporting us with correct pulley sizing, servicing/repairs, etc. Craig also confirmed that you can get a sc setup for up to 17psi of boost, but that comes without a warranty. Cost is $100 if done during a rebuild ($700) or $250 w/out a rebuild.

I'm in the process of putting together the list of materials and vendors, but its been slow going as of late. Stay tuned and let me know if you or anyone else is interested.

HuggyBear

im very insterested in this if its possible to do it with a reasonable cost for this kind of upgrade. using stock injectors is a plus if it can be done.

does anyone know anything about the camden SC package? i had a reply from them stating that thier kit would require aftermarket fuel injection(does that mean just bigger injectors????) or a switch to carb which i dont want. just wondering if it has any issues.

you certainly have my support for getting an SC package useable with stock fuel injection set up.

ill be looking into your web site as well for some info.

thanks!

SuperchargedRex

The 13B motors in the 2nd gen have two primary fuel injectors, and two secondary fuel injectors. (One of each for each of the rotors.) The motor runs on just the primaries below 3800rpm, then the secondaries come online. (Due to poor electrical grounding of the ECU, some guys experience a stumble when they come on line.) In a stock NA motor, all 4 injectors are 460cc/min, in the TII they are all 550cc/min.

What I have learned with the Paxton kit is that if you have already upgraded your intake (K&N cone filter) and exhaust (header, high flow cat, catback) then you will need to upgrade your secondary injectors from the stock 460cc/min to the 550cc/min out of a TII. (If you're flowing more air, you need more fuel.) The good news is that its a direct swap, no other modification needed. Basically what happens is that the computer thinks it still has the 460's, but its just spraying more fuel with the slightly larger injectors. I also opted for upgrading my fuel pump to the Rotary Performance pump because mine was the original with 142,000 miles on it. The kit also came with a boost dependent fuel pressure riser.

Before buying my kit, I spoke at length with Kathy Atkins over at Atkins Rotary regarding the Camden blower. Its designed for a Holley carbeurator (sp?) but Atkins sells an aftermarket FI that will bolt up in place of the carb. This aftermarket FI has its own computer, but they didn't have all the fuel curves mapped when I spoke with them a year and a half ago. It might be worth your while to check with them.