I’ve seen a few issues, this is various cars lately: 1, clamp flew off the submersible hose, and it was gooey when removed, apparently not all submersible hose is made the same, definitely worth a look. 2, compact aeromotive FPR couldn’t keep up with boost. Swapped to the more expensive aeromotive FPR and dyno logs confirm, it’s nearly identical to MAP readings in the logs now. Not sure of it would have been an issue on a N/A car. Hope this helps.

Thanks for the suggestions curly. I opened the tank and checked over the pump assembly, everything was tight, and no internal leaks while running. I shotgunned in a new fuel filter as it was the only item I had on hand. It's still dropping, but only by 10-12lb now, I didn't see any huge 20lb swings. I could still blow though the old filter with ease, so I don't think that's the root of the issue anyway. The biggest thing is it's still not a consistent drop, sometimes it drop 10lbs and holds, sometimes it tapers off, sometimes it holds rock solid pressure, and I can't find any constants to it.
I don't have a spare FPR, and my spare pump doesn't arrive till next week. For now I'll just leave it, if it messes with my fuel map some while on the dyno, I can always fix it on the street.

Dyno Day! man, I was NOT disappointed!

Rolled onto the dyno and made more power on a basemap then my old BP had made cranked all the way up. 157whp/153tq
https://cimg2.ibsrv.net/gimg/www.mia...8973e37098.png

30 pulls later she put down 210whp/167tq on pump 93.
https://cimg7.ibsrv.net/gimg/www.mia...5fb4ec379b.png

And for the final coup de grâce, put down 227whp/182tq on E85 after another 10 pulls.
https://cimg7.ibsrv.net/gimg/www.mia...9cc35817b2.png

I've used this dyno several times in the past and compared it to other local dynojets. It reads bang on with the others, these numbers are as accurate as a dynograph can be.


Wow. Car is a rocket now, and absolutely screams though the upper RPM's.
I did the tuning start to finish, which was a first for me. Very nerve-racking to say the least! My mind was blown when I found out that VVT was worth a whopping 20whp over no VVT.

I cannot wait to get it on track. This year should be very, very fun.

Great number’s, congratulations.

It looks like you can still optimize the VTEC crossover. Seems like you're losing at least 10 ft-lbs by switching into VTEC too early, which is causing a fairly large hole in the torque curve between 4-5k rpm.

Yup, I realized that later as I was looking over the graphs. I've since moved the VTEC engagement to 4500RPM, where it was set to 4000RPM. It probably wouldn't be an issue except in 1st, as I only loose about 2500RPM in a shift.

As a sidenote while I'm thinking of it, that crappy generic cone filter lost me 4whp in back to back pulls. Now that I have my ducting in place I can find a good filter that fits and move to that instead.

And as a continuation to the fuel pressure issue, it happened on the dyno as well, so its definitely not a slosh or pickup issue. I never had a pressure warn kick on(set to warn at 45lb), but it did drop to ~53lb and recover to ~60lb during several pulls as per my logs.

Side exhaust sounds amazing!

Man, that sounds great! Awesome work, I'm looking forward to hearing about your first time on track with it.

Loving this build!

Great results. That gain from pump to e85 was way more than I expected, I think it's the first Z3 on e85 I've seen. This is good news for me because with the new NASA rules with the Toyo RR's that allow much more power I wasn't sure if I could max the car out in ST4 at 210 to 215whp.

With the couple of things I'm going to try it'd be interesting to see if I can hit 230whp. Ported headifold, underdrive ATI damper, straighter exhaust, velocity stack intake, e85. Also, if you use a velocity stack with the cone type filter I've seen those pick up power everywhere on the curve. On my nearly bone stock BP going from normal filter to a velocity stack and filter of same brand and surface area it went from 107whp to 109whp and that 2whp gain was everywhere on the graph. Swapped while on dyno with no other changes.

Do you have a link for the stack, preferably one that can be used with a filter/has a filter built in? I'm 3whp shy of 230 on E85, but I think I'm about maxed out in terms of exhaust and intake optimizations.
I'll probably be severely underpowered for TT3, even with taking the sidepipe hit and running RC-1's. The goal would be to get the car(sans driver) to ~1900lb, but that would be pretty tough with all the aero and limited interior options. I need to hit the scales at RRR and see how badly I'll be outclassed.

Is it just aero that puts you out of TT4? Put blanks in the ramps, remove the dual element, good to go?

Really any plastic velocity stack and filter combo will work. I didn't know you were going for TT3 at this point, you're going to be so outgunned on non-hoosiers that you should just spend the money on track time instead. Even at 2100lbs competition weight with 245 Toyo RR your max AVERAGE horsepower would be 265whp so you would need an engine that makes maybe 270 to 275whp peak to be competitive.

BUT. If you put 245 Hoosier A7 on, you could run at max average 230whp. Then that would make sense to try to squeeze out a little more power, get the vtec crossover dialed in and you'd be able to run pretty close to the limit.

I'd have to read the TT4 rulebook indepth, I'm not sure what else might DQ me from TT4. If it actually is just those two items I might consider it.
The plan was to use RC-1's for the first few events just to fully dial in the car and work though any teething issues. I have a set of Hoosier takeoff 205's and 245's, but I might save those for hillclimbs as well. Don't know for sure yet.

I believe the modded front fenders will also bump you out of TT4... ?

Correct. For NASA, Aero modded fenders are a no go w BTM aero. Rear wing end plates probably to large, rear bumper cut looks like it exposes crash bar which is no go.

I don't see that motioned anywhere in the TT4 rules, but its a moot point, as...
Yup to all of that(lol it's not even a bumper cut, I just straight up don't have one), as well as having splitter ramps and a 6" splitter. To run TT4 I'd have to:
Source a bumper, trim 2" off my splitter, find new fenders(?) make new endplates, and remove splitter ramps.
This car already struggles for front grip so removing the ramps and trimming the splitter would make it plow even harder. I'll pass on TT4. I'm starting to like the idea of running Hoosiers and 230whp in a maximum lightweight build for TT3 more. I'll just have to find a good source for 225/245 Hoosier takeoffs, as lord knows I don't have fresh purple crack money.

The rules state "shall be limited to the following:", and what's listed doesn't include fender mods, other than flares.

I didn't realize this until someone at a non-NASA event pointed out my Left Lane fender vents wouldn't be TT4 legal, so I'm kind of in the same boat. Don't really want to run TT3, so I guess I'm not running NASA unless I decide to spend a bunch of money going back to stock fenders.

Like you said, a moot point with your car. For me, that and my Singular hood vents will probably keep me from running NASA, unless they change the rules.

I think I'll be right there with you if I ever get my K-swap going. TT3 is the higher car count in Mid-Atlantic anyway, so I may go K24A2 and run in 3 with 245 Hoosiers. To run RRs I would need to add 50 HP haha.

I run with Singular hood vents with NASA. The only issue was having to push down the front gurney flap to no exceed the maximum height to be able to qualify for the BTM aero credit (which I currently claim in TT6). If you're not claiming BTM aero then having the vents shouldn't matter.

Oh yeah I forgot about the fender vents. I get the intent of the rule, keeping the ~$80k ST4/TT4 builds for going even higher, but I wish there was a way to get certain mods approved by price-point.

I'd keep the fresh Hoosiers for hill-climb, as that seems to be what you're more interested in. TT3 around here is either slow ppl show up, no people show up, or you gotta be running 1:30-even at Road Atlanta or 1:58 at ViR :rofl:

Good news, all your mods are 100% legal in GLTC ;)