so, for those who are not familiar, the car is a Maui Blue 1989 Formula 350 hard top. Suspension has KYB shocks, UMI torque arm, Alston SFCs, Hotchkis LCAs and Panhard Rod. On the engine: Scat I-Beam rods, Keith Black hypereutectic pistons, Fluidampr, Dyno Don Headers/ORYP, Hooker cat-back, Fast Burn aluminum Vortec heads, ZZ4 208/221 cam, Accel 24lb injectors, Caspers heated O2 sensor, Ed Wright chip, Edelbrock Vortec lower intake, AS&M large tube runners, stock TB w/ air foil, stock plenum.

with the bold and underlined modifications in mind, does anyone have experience that would give a fair idea if swapping out to a First system would be worth the $1,000? anyone know what kind of gains i can expect, if any, by simply bolting on these hard parts? due to the apparent increase in volume, can i expect any vacuum loss?



i was thinking this, but maybe flat black with no accents.

 

Loss of vacuum....no
Gain in air flow....yes a lot

Ditching the Edelbrock base is a must, it only flows 240-250 cfm
The First flows over 300 out of the box.

 

thanks, Don. any loss of bottom end? think its worth the money vs. what i have currently?

 

I had a similar combination that I ran a TPI/SLP combo and the FIRST. The TPI/SLP combo was a fully ported base and plenum with "customized" SLP runners - I took them on and off the car grinding a little,, then doing three or four vericom (g-tech) passes until the ETs and MPH leveled off. The TPI/SLP combo was as "tuned" as it could be for that combination and the FIRST right out of the box performed better. The FIRST pulled almost as hard off idle but still had no problem granulating the tires. The TPI/SLP combo was almost impossible to get a good launch where as the FIRST was still hard to launch,, but manageable. The midrange and top-end on the FIRST was a good bit better.

The FIRST moved peak torque and the power band up a few hundred RPM compared to the fully ported TPI/SLP combo. Most GM based TPIs make peak torque at an RPM under the shift recovery point which is as much a problem with how it runs as the lack of upper rpm power. The proof is in the ET difference I saw – almost a half second,, which is about 5 car lengths in the quarter-mile at that speed.

Power band wise:
TPI/SLP - off idle to 5500 rpm - high-12.9s@105mph
FIRST - 2000 - 5800 - mid-12.5s@107mph
ETs are at the same track under similar conditions with temps in the high 80s

Here’s another comparison - a buddy with a 13.0 LS car would pull slightly away from me with the old 12.9-second TPI/SLP combo from a 60mph kick. I could blow his doors off with the FIRST. That same 13.0 car could also hand over the TPI/SLP combo from a dead stop on street tires,, bad,, I just could not hook the TPI/SLP. Again,, with the FIRST,, even though it was still hard to hook on the street tires I could flat blow his doors off. Also,,, I never ran a ported FIRST on the IROC, but would have expected about a .12 reduction in ETs over the box stock FIRST with relatively minor port work / clean-up. Not that it's bad out of the box,,, it's just sized to a stock exit and the quite large injector bumps can be dang near flattened out.

Whether that’s worth the cost of the FIRST, minus what you could sell and get for your current intake system, is up to you to decide.

Hope that’s helpful.

 

very. thanks.

 

@ Bad SS

what size injectors are you running?

i have Accel 24lb injectors on my current setup.

 

also, any forseeable fitment issues for a Firebird (has a more contoured hood vs. a Camaro)? it all fits under stock hood, right?

 

Does the first fit the vortec head pattern?

 

Vortec base is now available. The top manifold is the original and the lower is the new Vortec head design which is now available.
The FIRST® manifold can be used on the aftermarket multi bolt pattern aluminum Vortec heads. As cast the ports can be opened up enough to be used with the tall Vortec ports. So if you have these heads, just give us a call and you can experience this manifold with the Vortec style head!

 

Good deal. I'd say go for it. Should see some gain in performance. Stock edelbrock bases as mentioned dont flow to well and have smaller port cross sections. First should allow alot more flow and help pull some more rpm.

 

300+ was on the 2 worst ports on the FIRST base. both can easily be opened up for more flow.
if im not mistaken, the FIRST runners out of the box are as big as the SLP runners can be taken on a full port job.
i don't recall anyone ever posting up what a fully ported FIRST flows.
has anyone even done a max effort ported FIRST?
such as shame that the FIRST isn't Cali legal

 

I was running flow-matched SVO 24# injectors which I think flowed a little over 25# at 43PSI. Anyway,, the 24# Accel should be plenty.

I'll let one of the guys that are running a FIRST on a Firebird speak about hood clearance, but I don't think there is an issue. I know the Vette hoods are tighter and all they're having to do is grind down that hump on the T/B.

I will say the fitment around the rear oil sender "tree" is tight. I had to use a couple brass fittings from the hardware store and grind a little on the intake. Even then,, I installed the lower fitting in the block first,, then put on the intake. The IAC connection is a bear,, so I put in a four-wire weather-pac connector where I could easily disconnect it for IAC adjustment.

Also, I had bought one of the small cap HEIs earlier for the HSR and that was helpful, giving a bit of wiggle room for the fuel pressure regulator. However, the large cap HEI will work based on the instructions on the FIRST website.

 

there is a member here running this intake with great success and has a build thread. let me see if i can find it

EDIT: here you go https://www.thirdgen.org/forums/tpi/...injection.html

 

thanks, 86T/A_Ram_Air
now i'm feeling a little standoffish. still want to get it, but i see some considerable negatives involving the actual installation.

it sounds like a much bigger project than just basically a manifold swap, which is what i was originally bargaining for. and i'm not liking the idea of having to fabricate this and that to make the linkages work and other fitment issues. could be more of a winter/tax return thang.

 

You have to remember that the install is over a year old. Its very possible that FIRST has corrected those issues

 

I really wouldnt sweat it...those are small parts to worry about and as long as you plan for it ahead of time, you can still do the swap in a day. Good thread there letting you know what you need to be aware of.

 

i am that member who made that thread...... i really like the FIRST intake... It is truly by far the best performing out the box stock looking LTR intake... performs much better than the edelbrock/slp combo i had.... you can really tell a difference in the mid and upper ranger power... there are some things that you need to mod but it is well worth it..... if i had to do it all over again with another car i could do it all in a day knowing what i had to go through.... the only thing i would change about the intake is that throttlebody design... i did not like it at all and had a conversion plate made to use the stock type throttle body...

 

88fastGTA, I was hoping you would spot this and chime in. BTW wish we lived closer to one another, we could arrange a GTA photoshoot. I wanna find other nice GTA's to do photoshoots with