I’ve been away from the TGO boards for a while (work, kids, . . ). It’s been a long time coming, but finally had time to complete the engine mods I started last fall. Thought I’d share with the TBI crowd what I did and the results so far.

Starting point:
- Completely stock L03 (305) motor w/ underdrive pulleys
- T-5 manual transmission
- Hooker 2055 headers and Aerochamber cat back, cat delete, Y pipe dump
- 3” open element air cleaner
- 3.73 posi rear end
- Walbro 190 fuel pump at stock fuel pressure (12.5 psi)
- Tuned w/ EBL
- Extensive suspension mods (see sig)

Recent Engine Mods:
- Ported and polished 081 heads, back-cut valves, .015” head gaskets
- Crane 104224 (Powermax 2032) cam (214/220, .452/.465)
- GMPP timing set
- 1.5 Comp Cams full roller rockers
- Trick flow pushrods (with guideplates)
- Edelbrock 3704 TBI intake, bored to 46mm, port matched
- Stock 42 mm TBI, 68 lb injectors, 16.5 psi fuel pressure
- Heated O2 sensor

Engine ran pretty rough at initial startup, but smoothed out after setting timing and adjusting throttle plates to get correct IAC counts. As expected, fueling was way off with the all the mods, bigger injectors, and higher FP. After a handful of EBL VE learns using the wideband (closed loop disabled), the engine got happy with the VE tables pretty quickly. I can’t imagine how much time I saved using RBobs EBL and VE learn vs. the old way of ALDL datalogging followed by data crunching with Excel (thank you Bob). I used my old timing table to start with, which has worked surprisingly well, only a few knock counts here and there. Feeling safe with spark table, I slowly crept up on dialing in WOT tuning. After quite a few WOT tuning runs, got commanded AFR to match measured WB AFR at 12.5 +/- .1. At that point the engine was running quite well at steady state and WOT, but I still have quite a few dynamic fueling issues (surging, tip in hesitation, etc) that need to be addressed with acceleration enrichment (AE) tables. That’s the trickiest part of the tune to get right and I’m sure will take quite a bit more time to iron out the little wrinkles.

The heads are 081 castings, ported with 1.94/1.5 valves, bowl blended and polished, cut for bigger springs and guideplates, and screw in studs. I spent a lot of time working on the short turn radius and bowl area as well as cleaning up and smoothing out all the casting imperfections. A friend of mine back cut the valves to pick up a little extra flow.

I’m happy with the 2032 cam. Its cranes biggest “computer controlled” Powermax cam for SBC applications. It has zero overlap, which is what makes it computer friendly. It made a very noticeable change in idle (better of course), with a deeper, muscular tone and a slight lope. This cam with the Hooker Aerochamber cat-back sounds awesome. The engine runs noticeably stronger throughout all rpms, but especially up top. Before the mods, the stock motor ran out of steam just over 5000 rpm. With the new cam, heads, and intake the motor revs much more easily pulls hard well past 5500 rpm, pushing 6000. Datalogs are showing the TBI is starting to pull vacuum at high rpms, so I’ll soon be swapping out the stock TBI with the ported 46mm TBI sitting in the garage. I already have the intake bored to 46 mm, so it’s ready to go.

Anxious to see how much performance was gained, I went to the track a few nights ago to flog the new combo. Up to that point, my best time was a 14.66 sec @ 93.41 mph. That was with fresher tires and a perfect launch (1.98 sec 60’). However, the last time I was at the track I ran a 14.96 @ 91.5 mph with nearly bald tires that would not hook up. Unfortunately I’m still running the crappy bald tires, so launch is still limited.

My target was to hit 13.99 or better with the new combo. I made about 10 passes throughout the night, tweaking spark and WOT AFR along the way. (No loose articles allowed in car, but I hide my laptop on the passenger side floor to datalog). I was running with the exhaust Y pipe dump open, which definitely gives a performance bump. Five passes were below 14.10, with a best time of 14.039 @ 99.93 mph, with a 2.048 sec 60 foot. Oh so close. No matter what I tried, couldn’t break into the 13’s. On the bright side, the car didn’t go home on a flatbed and it gives me incentive to keep working on the tune and dialing everything in. With the larger TBI and optimized AE fueling (at shift points), 13’s will come, even easier if I replace the rear rubber. I also see a cold air intake in my future since my IAT is running 40 to 60 F hotter than ambient.

I can’t complain about these results for a L03. Calcs with these numbers suggest rwhp is around 245 and 310 hp at the flywheel. That about what I was hoping for and very close to what DD2000 predicted. Besides nitrous, any suggestions on how to squeeze a few more ponies without digging deep in the motor.

 

god job man. i wonder if I will ever understand this tuning,

 

wow, once you swap out those tires you should be well into the 13's with all those suspension mods in the back seems like you did a good job indeed. actually, i'd say the cam is still a bit on the conservative isn't it? a bigger cam plus a well ported TBI would make it scream some more for sure what where your trapped rpms like with the T5 and 3.73?

 

I agree, the cam is relatively mild. At the time I bought it I thought I was pushing the envelope for a 305 TBI, but now I'm confident enough with EBL that I could tuned a cam with another 10 deg duration and more overlap. Hope to swap out TBI this weekend with my ported one. Hopefully it will fix my high rpm vac issue and breath better on the top end.

As far as trap RPM's, with the 3.73's I'm hitting the traps a tick over 5000 rpm in 4th gear. IMO, 3.73 gears are perfect for a T5 car. They're a huge improvement over the 3.08 stock gears, but don't wind the motor too hard in 5th gear cruise. I have not verified at gas pump yet, but EBL says I'm pulling around 24 mpg on the highway.

 

what exactly is that high vac problem you're talking about? and do you mean high map? high vac would indicate idle imho

well, with the ported 081 heads and a bigger cam you should have a good combo in the long run! and looks like you're still getting decent milage despite 3.73 gears.

 

Pull some weight out of the car and you will definately see some 13's.

 

At WOT, the throttle plates are completely open and MAP generally goes up very close to atmospheric pressure, which is about 100 kPa. If the TBI is sized correctly, the MAP at WOT should stay close to 100 kPa as engine speed rises, dropping only a few kPa as you get to redline. My MAP is dropping down to 91 - 92 kPa (pulling vacuum) by the time I hit redline, which means the throttle body, air filter, or inlet air piping is starting to restrict airflow. I'm running a 3" open element, so I don't think it's the filter.

 

Carving out 70 lbs is good for about a .1 sec in the 1/4 on a 3400 lb vehicle. So 35 lb for .05 sec. I usually go to the track with the fuel tank close to empty to minimize fuel weight. I'm not ready to pull the seats out of the car and I'm not 35 lbs overweight, so it will have be be done with more horsepower

 

Yeah it depends how far you want to go really, I GUTTED my car all the way down to 2860 with more room to go. I can't wait to get a good handle on my tuning skills (which for a noob like me the EBL/ZT-2 combo is a godsend) so I can finally put all my parts on the car.

 

I have a ZT-2 as well. Data resolution is great at ~57 hz. I tapped into my ESC knock signal and have that wired to the user defined channel, so I can see in the datalogs when the knock sensor is active. With the ZT-2 and EBL datalogs, you can really see what is going on.

 

What type of open element base are you running? Stock spacer ring? What about the TBI, does it have ultimate TBI mods and an injector pod spacer? How about a TBI spacer? An open center 1" tbi spacer made my ultimate TBI moded unit more than adequate for a 315 HP 350 in airflow.





I was actually comparing a stock spacer ring and air cleaner to a moded air cleaner and TBI Powercharger at the time this was taken. The stock spacer ring is a choke point.

 

i need help picking out a cam. what made you decide on yours?
this is what i have:
350 bored.030 over 4bolt main
14102193 heads w/3angle vj DUDE SAID THE V-SPRINGS WERE CHANGED TOO, idk.
stock tbi 55# injtrs / open elment k&n 14x3
motorvation tbi spacer, injector spacer
stock intake that i gasget matched
hypertech coil & thermomaster chip
hooker 2055, catco hollowed cat, 3" hooker exaust w/aerochamber muf
t-5 w/308 grs STANDARD REAREND


FUTURE MODS:
HOLLY PROJECTIN INTAKE
2" TBI
BW 9 POSI W/372 n DISC BRAKES

many thanks for all your input guys !!!!!!!!!!!!!!!!!!!!!!! engine is out of the car so wanted to do the cam swap now. HAS TO BE HYDRO FLAT TAPPET, 1984 BLOCK

 

I'm running a bone stock TBI with the spacer ring removed and a 14X3 drop base open element. The lid on the air cleaner is rubbing on the underhood insulation, so I don't have any room for a TBI spacer to go up unless I do something to get more hood clearance. The 46mm TBI waiting to go in has the ultimate TBI mods and an injector pod spacer. I'm pretty sure that will do the trick.

 

Picking a cam that matches the rest of you combo (compression ratio, heads, intake, etc) is probably the most imortant decision of a good build. It depends on your horsepower and torque goals, which should be determined by how you plan to drive the car. If you drive the car mostly on the street with an occasional trip to the drag strip, then you want a cam that gives you good low and mid range torque, with decent performance a high rpm's. If it is a ***** out strip car, then you want a higher duration, high lift, high rpm cam, but that sacrifices low end torque.

But more basic than that is your abilty to tune the engine by burning your own chips (or flashing the ecm). Our 3rd gen TBI systems have very limited adaptive learning, so even with relatively minor mods you need to retune the car to optimize performance. If you put in a big cam and don't retune, you won't like how it runs, if it runs at all. If you have experience tuning, then I'd recommend going with a fairly agressive cam. If you don't have experience tuning, then I'd be cautious about going too big. With the engine out of the car, sounds like you don't have the option to ease your way into the tuning world before you tear into the engine. No offense, maybe you know how to tune and that is not an issue for you.

Sorry to answer your question with more questions.

 

You're right, i have no expirence in tuning the 3rd gens, all though i did change the stock chip to the thermomaster chip from Hypertech, which required a 160* thermostat and a lower temp fan switch. IS THIS CHIP NOT GOOD ENOUGH FOR MY COMBO?
the CAMARO PERFORMANCE HANDBOOK suggest the Competitions Cams "PURE ENERGY" hydraulic flat tappet for the CARBURATED 1987 & earlier, 202/212 duration, .429"/.438" @ .050 lift. 110* LSA.
HAS ANYONE USED THIS CAM ON THE 350 TBI SET UP ?

 

@kbraxton sorry gotta say that, you're probably better off starting your own thread for questions about your specific combo..

@91Rocks, thanks for explaining the map technique to evaluate intake efficiency, i read about it in the past but seemingly forgot what exactly is done. and i agree about not being ready to 'strip' the car for better drag times for me, it's gotta be done in full street trim, at least for a car that is not your typical ***** out dragger. (no offense robertfrank!)

need to get my ZT-2 wired up as well, along with installing the 2055 headers that have been kicking around in my garage for almost a year now.. only engine mod that i installed was my 3" aerochamber and EBL so far. i also started with stiffening up the suspension a bit.. seems we have similar parts & mods planned for our cars

 

I see your looking for more power without using NOS.

Thought about Wynjammer's SC Kit? I plan to purchase this for my LO3 305. It also lets you get rid of your AC and SMOG pumps as it includes an idler pulley. this would also allow more weight to be dropped from the car as well as power added. its kind of a 2 for 1 kit to me.

Take care, I will be following since I don't plan to swap out my 305, but get at least 350/350 from it, which more and more everyday seems possible with the new SC Kit from Wynjammer and tuning. If need be, I may add nos as well. But would like to stay away from that if possible.

 

No offense taken owner, it's all good,lol. Like I said it depends on how far you want to go and I'm willing to do it all.

 

Get those 2055's installed. You'll be really happy with how the car runs with the 3" aerochamber already installed. You'll really free up the exhaust restrictions and the sound will turn heads. Exhaust along with better rear gears were the biggest band for my buck short of digging into the motor. I did all the suspension mods before the motor. Kinda glad I did since the chassis was ready to handle more power.
I did the smog pump delete a few years ago. Bought the bracket and idler from TPI Specialties (I think that's the name). Very nice cast aluminum bracket w/ idler. I'm at the point of not wanting to spend too much more money on go-fast parts for the 305 unless they can be swapped to a 350/383, although I'm playing around with the idea of putting in a bigger cam on the L03 some time down the road. If you are willing to put the effort and expense into a blower for your 305, I think a 350/350 is very doable, and with EBL tuning should be reasonable.

Thanks for the interst in my progress. I'll post as I make more progress. I will hit 13's before the end of the summer or grenade it trying.

 

yeah, i'll try to slap an edelbrock tbi intake and an lt1 cam on there at the same time when doing the headers. plus i also need to hook up my afpr so.. yeah, i still have a couple of parts kicking around that need to be installed. talk about being too busy lol.
i started off doing my rear suspension, at the same time of upgrading the fuel pump and installing the aerochamber. still need to do all the front end
bushings and install rear gears + lsd and my alstons - then i'm ready for serious power

thanks for your hints
ownor

 

Understand the better off with a 350 part, but you state you may be running around 245whp, add the sc and some more tuning and you have exactly what I want. Also I want to stick with my TBI 305, because everyone says to go to a 350. My car will be more suspension related than power, also another reason I don't want to swap a 350 in. MPG as well and also needing an engine stand and cherry picker.

Take care, can't wait to see more on this mission.

 

Swapped out TBI with ultimate mod 46mm TBI last night and also installed injector pod spacer. The spacer of course raised the rear fuel line fittings ports at the back of the pod, so additional grinding was required for the fittings to clear the TBI body. Also raised FP while I had things apart since my duty cycle is getting into the low 80's under high load conditions. It was getting late, so not much time to datalog. Noticed engine was running rich (from increased FP), so I'll have to do some Learns to get VE back in line, along with adjusting BPC. I did see that I was pulling less vac at high speed (only 2 or 3 kPa at 5700 rpm) with the bigger TBI, plus the AFR behavior during AE events looks leaner, presumabely from flowing more air. So it looks like the bigger TBI is doing it job, just need to get the tune dialed back in.

 

91RockS,

This is a fantastic thread that outlines the importance of tuning even with a mild build as yours. It is nice to see well thought-out TBI projects that produce solid results, all the while showing how crucial tuning is to getting a new combo to run. Would you mind posting an itemized list of all the tools and equipment you used for tuning? No two tuners on this site use the same equipment and our reader base would likely be more encouraged to try their own tuning after reading this thread. Your combo is very similar to many of the combos that appear on this board everyday, as it is simple in nature and does not implement any advanced TBI caveats that necessitate experienced tuning skills. Thanks in advance and keep us posted on your progress with the larger TBI unit!

 

Thanks for the props Shifty,

To answer your tuning tools question, I'm using the same as most other guys, nothing special, but I'll give you the run down.

To start with I have an EBL classic, which is the original version RBob released. I already had a Prominator (flashable chip with 8 bin selector switch), so I can flash bins without burning chips. There are plenty of posts written about the excellent usability and tunability features of EBL, so I won't go into that other than to say its reduced tuning time dramatically, fantastic product. For anyone running a GM TBI system, EBL is the only way to go unless you absolutely cannot afford it. I had my new combo running darn well in after about three VE learns.

For tuning software, I use Tunerpro RT. It’s the only tuning software I've ever used, so I have nothing else to compare it to. Nonetheless, I have no beefs with it, works very well for me.

Finally, I have Zeitronix ZT-2 wideband O2. I had it back before EBL in the days of WINALDL datalogging, so I relied on it heavily for dynamic tuning. I have the O2 bung and sensor located in my custom Y-pipe that fits exactly where the cat used to be. The Y-pipe has the exact same length and flanges as the cat, so it can be swapped in and out easily if needed. I pop the cap off the Y-pipe when I'm at the track (3 wingnuts) to run full open exhaust. I tied my MAP sensor into the ZT-2 MAP channel. I found that the measured MAP value the ZT-2 reported did not match my true MAP value, so I built an adjustable circuit using a variable resistor to calibrate the signal to the correct value. The ZT-2 also has one used defined 0-5 volt channel. I tapped into the knock signal that goes from the ESC to the ECM so I could see when knock was occurring in the datastream along with AFR, rpm, MAP, and TPS. The knock signal is 0-9 volts, so I built of 1/3 voltage divider to get the signal in the range the ZT-2 could read. Some guys complain about the ZT-2 user software, but I really like it. It's not fancy, but what it does, it does well. It provides a very visually intuitive real time display/graph, sampling at a respectable 57 Hz, so data resolution is excellent. It really provides a clear visual of what's happening with AFR during AE events. Over the years I've used the rpm data as a poor man's accelerometer. I do a 3rd gear pull staring at 1500 rpm to redline, determine the number of data points from accelerate from 3000 to 5000 rpm, and divide the number of data points by 57 (the sampling rate). That yields the time (in seconds) for the engine to accelerate from 3000 rpm to 5000 rpm. It’s a great way to compare the WOT performance of one bin to another while minimizing variables (like shifting). Since the advent of EBL, it has some a very nice analysis tool to measure acceleration performance easier and better, but I continue to also use my old method since I have a lot of historical data with it. For WOT tuning, I first dial in measured AFR to match commanded AFR throughout the powerband. Once that is within +/- 0.1, I start playing with commanded AFR, finding what the engine likes best, somewhere in the range of 12.0 to 13.0.

That’s all I have time for now.

 

91rocks

Your accelerometer derivative method is a practical approach to solving a problem. You can cheaply add electronic 3-axis accelerometer to EBL (or ZT2) for a bout $30. Solution is available from analog devices ADXL330/335:

http://www.seeedstudio.com/depot/wii...330-p-107.html

just add 5 to 3.3 volt supply to above.

ADI offers eval PCBA at very reasonable price through Digi-Key:
EVAL-ADXL335Z:

http://parts.digikey.com/1/parts/163...-adxl335z.html

Sorry for electronics related post.

//RF

 

Did more datalogging with 46mm tbi. Performance at WOT actually seems to be down. Motor is not pulling as hard. When I swapped out the TBI, I changed four things (always a bad idea): TBI, installed 1/4" injector pod spacer, increased fuel pressure, and changed to lower octane fuel. First thing I noticed was AFR at WOT was way rich from the FP increase. I've got that nearly back to perfect after a few burns. Also switched back to higher octane fuel. Performance has picked up, but not yet back to where it was. I'm starting to suspect the pod spacer. Although it raises the injector pods up to reduce airflow restriction into the throttle bores, it also raises the fuel spray cone higher in the bore, almost to the top of the lead-in radius. The other thing different is the 46mm tbi has the ultimate mods, which remove the lead-in walls on top of the tbi body. Even though the ultimate mod tbi looks like it should flow better, GM didn't put those lead-in walls in without good reason. I'm wondering if the raised fuel spray cone along with the elimination of the lead-in walls are resulting in poorer fuel mixing and atomization. I can't think of any other reason why performance at wot would be worse with the larger TBI (all other things being equal). I'm going to pull the pod spacer out and see if that makes a difference.

Anyone have objective data that shows the pod spacer improves performance?

 

i remember someone posting about his friends dynoing their car with the spacer and it worked some.

 

I think you're probably right about the spacer, it's designed as a bolt on part(to an otherwise stock piece) and atomization definately affects performance.

Good luck and tell us what happens-

Eric

 

No data but have tried with completely stock car and now, no power and running difference at all. It was like 3.5mm over stock hight (I removed the stock gasket).

For power maybe you need to ad little SA, 46mm TB should help the cilinder fill a little more, requiring to be sparked a little earlyer.

Increased FP should atomize better.

 

this thread has lots of good information in here. thanks to everyone that contributed.

the accelerometer RFmaster proposed actually sounds like a reliable, permanent and consistent way to measure performance. i might get one to hook up to the EBL when i do my ZT-2.

91RockS, let us know what you result you come up with after removing the spacer. i think it'd be possible that atomization really suffers from the raised injectors and the removed lead-in edges of the TBs.

 

This likely varies largely manifold to manifold. Some combinations respond differently than others. My engine LOVED the extra airflow from the raised pod and TBI mods.

 

tbi root supercharger tuned? and 13's would be there

 

Well I removed the 1/4" pod spacer and did a back to back datalog comparison. 2nd and 3rd gear acceleration were slightly quicker, 1st and 4th no measureable difference. After getting my WOT AFR back in line (after FP increase) and pod spacer removed, overall performance with the 46mm tbi is about the same or slightly better. That's based on analyzing datalogs. Plan to get to the track soon to get some 1/4 mile times. Based on what I've measured I'm going to continue running without the spacer. Just for kicks, may swap the stock 42mm tbi to see what happens. I'm running 30° total SA, all in at 3600 rpm. I'm going to creep that up and see if I can gain a little. With iron 081 heads, I don't expect to push that more than 2-3 degrees before knock becomes a problem.

I'm also about 90% done building my cold air inlet, fed by ram air. Hope to get that finished up by this weekend. It's a little different than others I've seen on TGO. Probably start a new post when it's done.

 

You might be suprised, I ran the 081s in my van on a 10.0:1 310 with flattop pistons and they liked 36* of advance at 2,800 and 38* over 4,200. They are a slow burning head with not much swirl or tumble. The 305 has a small bore as well. The 081 head TPI engines had 36* total advance in 1985.

 

Fast, you might be right. With the stock swirl ports, I could only run 27-28° and was on the ragged edge of knock. With my ported 081, I'm not getting the slightest hint of knock at 30° with CR at roughly 9.6:1 and stock pistions. Time to start buring some bins and load up the bin switcher!!

 

Bumped the timing up 3° to 33° at WOT and datalogged. Measured about a3-5% improvement in acceleration with no knock counts, so I'll bump it up a few more degrees and try again. On the way home I noticed the dash lights seemed dimmer than normal. Battery voltage gage was reading low. Checked voltage with EBL, which showed 11.4 volts. So I have something going on with the charging system that is not helping me. Hoping its only the battery (9 years old) or the alternator (original from 1991).

Anyone have any suggestion on diagnosing the low voltage beyond battery and alternator ?? Plan to take the battery in and get it load tested, then do same with alternator.

Separately I ran my new cold air inlet. At 65° F ambient, my IAT usually runs between 115° and 125° with 14" open element. With the CAI, IAT is running at 75°, a 40-50° drop!! The relocated/isolated filter fed by ram air is really cooling down the inlet air.

 

hey that sounds pretty good on the timing and your CAI got any pics of that new setup? also, where did you mount your IAT? that's a nice temperature drop for sure!

hope you get your charging system back up to running alright. to me sounds like the alternator. yours' seem to have been holding up pretty well so far, i'd say that 1991 is already a lifespan back for these alternators hehe. you are running underdrive pulleys right?

 

I see that you're running 1.5's. Have you thought about bumping up to 1.6's? that might give you the litte added nudge to the 13's that you need. That should bring your cam up to this 217/223 @.50 482in/.496ex .If your springs can handle the extra lift I think it would be helpful.

 

robert, how do you calculate it? i tried but I think I am doing it wrong because it comes out too high.

 

I found a pretty good calculator awhile back, here's it is.

http://www.thedirtforum.com/toolbox.htm

http://www.thedirtforum.com/rockercalc.htm


IIRC usually duration goes up about 2-3 points when adding a higher ratio.

 

thanks a lot. it only seems to work on IE though.

 

When I was putting the top end together, I originally had 1.6 rollers to install, but I found there was not enough clearance between the push rods and the pushrod holes in the heads. The holes had been opend up to .500 when the heads were machined, but 1.6 geometry moves the pushrods outboard to almost to zero clearance with the head. Didn't want to take any chances, ended up putting in Comp Cams Gold 1.5 full rockers. They were almost too pretty to install.

 

For the cold air inlet, I used a Spectre plenum carb hat w/ 4" piping over to a K&N cone filter positioned in the left front corner of the engine bay. This is where the evap canister used to reside!! IAT sensor is installed in the back side of plenum (had to drill .680" hole in casting). My plan is to build a fabricated aluminum airbox around the filter to isolated it from the engine bay, but that is yet to come.

The key to the big air temp drop compared to my open element is that I am feeding ram air into the bottom of the filter by a 4" flexible duct that is piped into the back of the air dam under the radiator. I drilled a 4" hole into the bottom of the tray where the evap canister was mounted. The inlet to the ram is mounted to the back of the air dam (4" hold drilled through air dam). This air duct is directly in line with the airflow through the lower portion of the front grill, so as the vehicle gets moving, cool ram air flows through the front grill, into the duct and up into the cone filter. This might sound like a little Alabama engineering, but its keeping my IAT at a mere 10° above ambient, and the ram air duct is completely hidden unless you crawl under the car. Once I get the air box built, the inlet temp should drop even more when the filter is completely isolated from engine heat.

Pics attached.

 

I expect that the CAI modification had a tremendous seat of the pants improvement over the open element on the hot days around town. Going from 125*F to 75*F is a 50* drop and worth probably 7-10% HP, depending on how sensitive the engine is to timing. Hot intake air temperatures help cause detonation at heavy throttle and loading.

 

I definitely felt a SOP improvement with the CAI. Global warming isn't happening in this part of the country, temps have been unseasonably warm, so have not tried it yet in hot weather city traffic.

The only questionable aspect is the angle the carb/tbi hat sits as shown in pic. The position of the inlet favors better airflow to the driver side injector. Air going to the passenger side injector must first flow around the opposite injector. There appears to be adequate area for the flow to get there, but it would certainly be more equlized if I could shoot the inlet straight ahead. Problem is getting 4" plumbing to my airbox . . . not enough room to get in front of the alternator and over radiator hose.

Seems to be working well regardless.

 

I don't know if you want to do it, but you could relocate the battery and have the other tubing where the battery was.

 

How much did you end up spending I want to put the filer where the canister goes and build a shield for rain.

 

The carb hat was $75, plus two aluminum elbows and three rubber complers, about another $75 (all Spectre parts thru summit). $45 for K&N filter. I bought the strait piece of 4" pipe from a local metal supply house for a couple of bucks. All told, not cheap. The hat is a nice cast aluminum elbow (no doubt cast in china). All the Spectre stuff comes in premium boxes, packaged in expensive cinch-up silkly bags . They should forget the primo packaging and lower the cost since it all ends up in the garbage.