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That $4,500 price is for the complete plug and play system with all sensors, harness and ECM. Even includes injectors and fuel system. It's made for those converting from carb. We only need the intake, rails and throttle body, especially if you've already done real power up grades and have found a method for programming your ECM. I have ACCEL DFI. The intake alone sells for $433 on Summit. The Eddy TB sells for around $360-380(can't remember for sure and too busy right now to look). In fact, as far as the TB goes, I saw one case where an installer made an adapter to fit his TPI style TB to the front of the XT.
Looking at the plenum design though, I think that it relies on the LS style TB for flow management and optimal performance. Since I have built a high flow air filter housing, the big 90mm TB should fit my 4" intake hose perfectly. I also like that the XT is right at the same height(not including TB which sticks up about .800") as the TPI. This should allow use of the same strut tower brace as I have now for my TPI car. May take some slight mods but should fit okay. It will require a longer throttle cable and a longer TV cable for those running the 700R4. Lokar offers the cables needed. Looks like total install cost would run around $1,000. Believe me, compared to the cost of building a high flow TPI and comparing the capabilities of the two, it's not bad.
I just don't know what the intended power range is for this guy. I hear that it was intended for the 450hp range which is a little on the low side for my goals. I think maybe I'll message Eddy technical and pick their brains. I did read on their tech forum where one installer was going for 500hp. The tech adviser didn't say it wasn't doable. It does have a 1,500-7,000 rpm power band(according to Eddy's online catalog).
I plan to build a 400+(not sure whether I'll stop at 406 or go on to 427). This would make killer torque with the TPI but would bring my rev ceiling down even lower. I was going to build my own tunnel ram style intake, but that's a big proposition since I don't TIG weld or have machining capabilities. Was waiting for my kid to start the welding program in college but now he's decided he wants be an electrician instead(damn ingrate:)). So, I've pretty much decided that it's either going to be the HSR, which could work, or the XT which I think I like better.
Thanks for your reply. The XT is a mid length ram style like the HSR, just a little shorter, aside from the TB. It would be nice to see a side by side comparison of the HSR and the XT to see how they stack up. I do like that the XT was designed as a front feeder EFI intake, rather than being an old top feeder wet flow with injector bungs and a front feeder plenum added on. That being said, the HSR does perform.
I've seen the XT with a 1205 gasket and it would need cleaned up to match that. Do you know anyone who has done that? Was it a problem?
Next to the GM ramjet, the XT seems to be quite superior. Larger plenum, larger ports and air gap. Also, the XT is pretty wide open, so if it needs to be welded on for more porting, it would be easier than on
most designs.
EDIT: On a closer look, one possible advantage to the ramjet is the drop floor plenum. It seems like the drop floor is going to provide better volume to the front cylinders. Again, I haven't seen any real test results for the XT, not on higher HP motors.
Okay, I pretty much got my questions answered, as far as the intended power level of the XT, just by reading posts on the Eddy tech forum. It appears that the XT is intended for up to 550HP. I'm sure with porting it could go higher. It was stated that the XT "will not be a power restriction at the 550hp level". Thanks to the members who responded to my thread. It appears that the XT may in fact be a great alternative for those of us looking to move up from TPI. Once I do get around to the install, I'll let everyone know how it actually fits.
One thing I read a few times is that "the XT is not compatible with factory 87 and later center bolt iron heads with the off angle 4 midriff manifold bolts". My Trickflow G2s have the off angle bolts. The Superram base was made to fit either straight or off angle style heads. Anyone who knows SBC of that era knows that making something like the XT fit is a simple case of cutting the 4 midriff bolt holes oblong in the manifold. There are even wedged washers available to help this work. I don't know why Eddy tech isn't telling people this. Do they not realize it?
One thing I keep forgetting about is the distributor clearance behind the XT's plenum. I still don't know if the small cap(external coil) HEI distributor will clear. Does anyone have any info on that? Anyone tried the install?
EDIT: Okay, just got off the phone with Ron at Edelbrock Tech. He says that while the large cap HEI is too large and will not clear, the small cap HEI will work fine with the XT manifold.
I'd like to see how this goes for you too. My buddy currently has the Vortec version of this intake on somewhat RamJet 350 Clone. It's a TPI 350 bottom end with the RamJet 350 cam, 1.6:1 Full Roller Rockers, Edelbrock Etec 170 Heads, The Pro Flow XT intake and a stock LS1 Throttlebody all controlled by a Fast EZ EFI 2.0 & Their Dual Sync distributor. On the super conservative EZ EFI base settings it's obvious that the TPI RPM limitiations are no longer an issue. The TPI like torque is still there but I'm going to attribute that to the intake & cam combination, not just the intake. The engine is still down on power due to the fact that we haven't really started to play with the settings and it's running quite rich. The restrictive 2.5" exhaust doesn't help either. With a good exhaust and tuning this combo should net somewhere in the region of 360-380 HP and about 400 TQ at the flywheel. The Vortec version of this intake is used on the Edelbrock EFI crate motors and the power numbers and RPM ranges are quite impressive for street motors.
As an alternative to the TPI this will probably work out the same as the LT1 intake swap on an otherwise stock motor but to really take advantage of it a complementing cam and proper tuning will be pretty much required
I suspect the reasoning for the lack popularity of this intake is 3 fold.
1. LS Engines and parts are so plentiful in the USA and the LS family responds so well to mods that a lot of people just go LS.
2. Emission. There are no emissions provisions on this intake. This may not be the case in all states due to emission exemption on 25+ year old cars but don't quote me on that.
3. To fully use this intake and not actually lose power a lot of supporting mods and extra expenses are required to use it to it's fullest.
So what I'm gathering from the discussion is that with the XT intake and edelbrock rails a factory (no ninth injector) TPI harness and ECU with the addition of pigtails for the TPS and IAC on the LS throttle body could work? With a little modification to the fuel pressure reg location and ECU programing? Is that correct? The XT top end is nearly a 1800 cfm improvement over the stock tpi on paper so how much larger would a guy have to go on the injectors? I've built many a carburated sbc but this will be my first venture into building with efi and the more info the better. I'm hoping this setup will work for a father/son build of his first car a 86 z28 5 speed. It has a vortec 355 that will be suffocating under a stock tpi and by the time we get the vortec base and a GOOD set of runners and do the port work I could have bought the pro flo xt intake at less than half the cost.
The dimensions are on Edel website. I run a Vic Jr SP manifold with a 1000cfm Edel TB. I believe that may be the Pro Flow package. I however run an after market ECU(Dynamic EFI/EBL). With a 2 inch procharger bonnet I was rubbing on the hood of My C4 vehicle. I shaved machined the bonnet by .24. inch. Then the bonnet was rubbing on the R angle heater hose nipple outlet so I had to shave it as well. Now it clears by .25 in to hood and clears the R angle nipple fitting .01 in. as well. You may have same issues.
08-19-2015, 12:32 PM
