ASE doc

Hi everyone, I just ordered my new intake manifold Friday. It will be a bit before it gets here. I get the sense that Eddy produces the XT to order. I'll be installing the intake along with the matching TB and fuel rails. The control system will be my existing ACCEL DFI gen6. This new intake will replace my ported TPI.

Before it goes on, the Pro Flow will be cut open and ported to clean up the casting and optimize the plenum and runners. I may also add a few cubes to the plenum since it will eventually reside on a 406cid and the larger plenum will help top end power on the larger motor.

The Pro Flow is 9" tall at the highest point where the 90mm TB attaches. Behind that, the plenum top is 8.2". The TPI is right at 9". This means hood clearance should be no problem. There will be a small issue of modifying the 4 midriff bolt holes to fit my Trickflow G2 heads that have the 15* off angle(87+ cast iron L98 style) midriff bolt holes. I'll have the fabrication shop that does the welding on the plenum help me with the bolt hole mods.

As far as I know, this will be the first time the XT has been installed on a 3rd gen F-body. I have seen it installed in place of a Superram on a C4 vette. The result was a solid power increase, and that XT was installed out of the box without cleaning up the runners.

This project will span the next several months as I acquire the remaining pieces and get everything ready for a weekend install. I'll update this tread with each step and plenty of photos.

mrestrictrplate

iTrader: (2)

Great swap I will be following. Will you dyno or do before and after 1/4 mile comparisons? Thanks Chris

ASE doc

Hi Chris, It was my plan to do before and after 1/4 mi tests. I ran the car two years ago, albeit with a failing fuel supply system and restrictive 2.25" collectors. Glad I didn't waste the motor running it out of fuel. The time and trap speed in my sig was the first and best run of that day. That time and speed was with my hood unlatched too lol, that's a fun story.

The changes since that race day are the new fuel system and the exhaust. The car certainly seems faster with the 2.5" collector pipes. Didn't notice much difference with the new fuel supply system. I am thinking of getting out to the track for NAPA Day at the Drags again this year to see if the car is faster than last time. That would be my before to compare with after the XT is on. Right now I'm just so focused on the XT swap that I've also thought about skipping track day this year.

Bummer though, the Aeromotive A750 pump that I reused in the new fuel system went bye bye on me two days ago. Good thing I guess that the car never even moved from its bay in the garage. I will say that this has been a tough pump. It lived a hard life getting fuel starved, vapor locked and run on too low voltage several times. I was surprised it still worked as well as it did when I did the new system. Labscope testing verified that a couple of windings, or those spots on the commutator, went open.

I decided on the Fuel Lab Prodigy 41401 pump to replace the A750. The Fuel Lab pump is brushless(very cool new technology) and dual speed. With a pulse modulated speed control it can be variable speed. For my application, I'll just run it on constant low speed. On low speed it flows .9 GPH(443lbs/hr) at 70 psi with 10 amps current draw. The best part is its 125psi max pressure rating, since I like to run small injectors with high pressure. I wired the new fuel pump power supply with dual 30 amp relays and 10ga wire so it has ample capacity for the new pump. As a bonus, the Prodigy pump is almost the exact same size as the A750.

So, I had to turn the XT manifold back to Summit and buy the pump instead. The manifold was scheduled to arrive here in two days. I almost cried having to turn it around. I'll get back onto the intake swap next month or so after some more side work. Right now, I'm waiting two and a half weeks for the new pump to be built and shipped to me. The guys at Fuel Lab told me they're building them to fill orders right now.

ASE doc

New pump got here today. Three and a half weeks waiting, but worth it for a great product. The Fuel Lab 41401 installed right where the A750 came out, even fit in the same brackets. Made the install quick and easy.

Just in time for NAPA Day at the Drags on Friday. I made sure after the install that my Mallory regulator with AN-6 return will allow adjustment down below 40psi, for when I install the XT and larger injectors. My math for what its worth says I'll want to run the new injectors at 45-50psi. I had to set the regulator down a little to run 70psi with the new bigger pump. I'll keep my gauge connected on the drive home tonight to be sure it holds 70psi with the engine at max VE.

Bummer is that by the time I paid for the tow(my buddy charged me $40 for 12 miles on his flatbed, sweet deal), tune up parts, oil and filter, and entrance fee for Friday, my parts fund is gone. So now I start from scratch. It's all good though. It will be cool to see if there's any improvement with the work I've done so far in preparation for the XT. I'll be back on track for the XT in a month to six weeks.

ASE doc

I've forgotten about this thread. I'm still doing the XT intake swap, just got sidetracked by other issues. My transmission started slipping in 3rd gear after the drags. The cost of parts for repairing it is about $300(it is practically brand new since I built it 3 years ago), which is no big deal but I also have other responsibilities that need to take priority over the car. Plus, my wife wants some stuff herself and happy wife means happy life, especially for a guy with a car fixation.

I should be back on track with the XT swap by the end of December. I'm doing some side work over the next week that will help move things forward. The car is in winter storage now til spring anyway. Once I have the trans parts on hand, I'll probably get it to the shop for a weekend trans repair, then back into storage and continue saving and acquiring intake swap parts. At this point I expect to do the swap itself early next summer. In the meantime, I will update this thread as I gather the parts and do the porting, prep work on the intake itself. I still need to finish my exhaust too. Getting tired of the loudness. I have all the pieces for it, just need to get it done.

As far as before/after testing goes, the time and trap speed posted in my sig is the best time and speed from my TPI. The next time out at the track will be with the XT installed.

Larry

You'll love the pro flo XT. I have one on my 86 Corvette. I don't understand why we don't hear more about them. Keep us posted, I never had a tpi on mine to compare it with.

eutu1960

how was your bottom end compared to the TPI and what cam did you use.

ASE doc

TPI does just what it was designed to do. It increases low end torque. It does this at the cost of midrange torque and top end power. In so doing, it produces a narrow power band. I built my motor to stretch the power band of TPI as much as possible without cutting runners, which wouldn't really be TPI. The engine I built will produce 450hp on pump gas with the right intake but even my modified high flow setup only gets about 400hp out of it and power drops fast above 5,000. This leaves alot of potential on the table and this is the downside of TPI. You get great torque down low, but a very narrow power band. This motor should be making power up to 6,500rpm with my heads and cam. (Trickflow G2 heads ported, ZZX cam-240/240 @.050 .560/.560)

In comparing TPI to the popular EFI alternatives like HSR, Miniram, or the Proflow XT, the reduction in low end torque is more than made up for by the wider power band. What I've heard everyone say who's made the change is that they don't even notice the loss in low end torque. They're too busy loving the overall power increase. It's peak torque vs average torque. Higher average torque makes a faster car than higher peak torque.

eutu1960

Thanks for the reply even though its an old thread, I ended up staying with my tpi and added some as&m large tube runners plus porting the plenum and base, it was just easier and more budget friendly and for the way I use my car it works very well, it would still be nice to try a better breathing manifold though.

ASE doc

Glad to see you're enjoying your car. That's what it's all about. It's been a long summer with my Beasty tucked away in the garage under its nice warm cover, with its broken rear diff. If you visit the Transmission and Drivetrain forum you'll see that the new 9" from QP is about ready to install.

The AS&M runners are the same as the TPIS runners that I have. If you'd have waited, I'd have offered you mine:-) they're in perfect shape. I also have the ACCEL Superram base that I ported to match the ported Trickfow G2 heads. Still, the motor will do so much better with an intake that better supports it's potential. I'm really looking forward to freshening these heads up (after 40Kmi) and bolting them and the new intake onto a brand new engine build. Still not sure whether I'll go with a 403(400 bored .020 over), or go bigger with a longer stroke. My son's getting involved so we'll probably get going on the engine build next summer. I do want to enjoy the new intake on my 355 for one summer first. All so exciting.

eutu1960

Good luck on the new build. I have thought about doing a new build also but just not in the budget, right now I need to determine an engine vibration I have between 2500 rpm and 3500 rpm but I am waiting on to put the car up for the winter to do so.

ASE doc

I'm so sorry I don't get to the forums more often. When looking at a vibration, you want to isolate the cause. Try running the car in a lower gear to the same rpm range. You want to be sure whether it's engine or driveline. Driveline vibration is common, caused by a binding u joint. Engine is less common.

eutu1960

I fixed the vibration last winter it turned out to be the Trans, Torque Converter https://www.youtube.com/watch?v=I-9JovNDcuI&list=PL5AMhVA-RNuRR2MW-s9I7jbF_Zp1fwQv9

https://www.youtube.com/watch?v=gTIAL8zRdr4&t=1s

ASE doc

Cool.

DuaneB

hey I’m starting to do the conversion over now and running into a few issues. Wondering if you can help. Thermostat housing they say use stock one but my alternator is right there as what cable and pedal setup did you use ? Thx

ULTM8Z

Count me among them. I love my Miniram...