Need help deciding on L98 Intake Mods
Thread Starter
Racer
Joined: Feb 2004
Posts: 445
Likes: 1
From: Atlanta GA
Need help deciding on L98 Intake Mods
Hello All! The Vette's in the shop and I just found out that there is a gasket leak in the lower base of the intake. Since the entire intake will need to come out to fix everything (according to my mechanic), now seems like a good time to do the intake mods. Right now I'm thinking of going with the Edelbrock base and larger diameter runners...Summit sells the pair for $719.99. To maximize the gains from this should I also send the plenum off to T.P.I.S. to get it ported and polished. It would only cost $100.00 + shipping. I'm looking for a little more power from my basically stock L-98, without getting crazy; and I would like to budget around $1,200-$1,300 for everything (and I lack the time, tools and expertise to do the mods myself). Is there anything that I'm missing here? I'm hoping some of you experts can chime in as to whether or not this is a good combination.
Thanks for all of your help!!
Thanks for all of your help!!
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
You could probably find some of those parts used, like the base and runners, for alot cheaper. Maybe not in your time frame though. If you could change the camshaft and have the valvesprings changed within that budget it'd be nice.
Otherwise it sounds fine to me.
Otherwise it sounds fine to me.
Le Mans Master
Joined: Jan 2003
Posts: 6,187
Likes: 309
From: SIMSBURY CT
St. Jude Donor '07 thru '25
Since your mechanic is doing the job, did you get an estimate for just making the repair? Then add the cost of your parts. I would guess the budget of $1300 would not be enough. I'd like to hear how you make out with this because I will be facing the same decision you are making in the near future.
Thread Starter
Racer
Joined: Feb 2004
Posts: 445
Likes: 1
From: Atlanta GA
Hello 65Z01,
Mods, only the basics: March Power & Amp pulleys, cat-back exhaust, front y w/o precats, removed cat, hypertech chip, throttle body spacer, and the infamous TPI airfoil!!
The next major mod will be long-tube headers...which are a must!! I'm considering roller rockers, a custom tune chip and an adjustable fuel pressure regulator. I have no plans for anything major (heads, cam, etc.) If and when my 350 gives up (has 92,000 on the ticker right now), I would definitely consider a 383 for more power.
Mods, only the basics: March Power & Amp pulleys, cat-back exhaust, front y w/o precats, removed cat, hypertech chip, throttle body spacer, and the infamous TPI airfoil!!
The next major mod will be long-tube headers...which are a must!! I'm considering roller rockers, a custom tune chip and an adjustable fuel pressure regulator. I have no plans for anything major (heads, cam, etc.) If and when my 350 gives up (has 92,000 on the ticker right now), I would definitely consider a 383 for more power.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
With those mods you will likely gain some performance from doing the base & runners. BTW, you can get an Accel base and AS&M runners for around $400 each, so the price is close to that of the Edelbrock parts.
I'm not sure about the labor on doing the intake gasket but it would seem as though installing the new base & runners should not add any to labor costs.
After you do the intake it may be time to consider 1.6:1 RRs and have your WOT shift point raised well into the high 5k RPM range.
I'm not sure about the labor on doing the intake gasket but it would seem as though installing the new base & runners should not add any to labor costs.
After you do the intake it may be time to consider 1.6:1 RRs and have your WOT shift point raised well into the high 5k RPM range.
Racer
Joined: Jan 2005
Posts: 315
Likes: 0
From: tomahawk wisconsin
go buy a super or mini ram intake.that will be the biggest bang for your buck.plus you get to get rid of the restricted tpi intake all together.a mini ram just sold on ebay for 900.00 and it was complete.another guy on here has a superram for 1000.00....your machanic shouldnt charge that much for the intake gasket repair.
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Thread Starter
Racer
Joined: Feb 2004
Posts: 445
Likes: 1
From: Atlanta GA
Thanks ar91c4,
I've been looking around at the mini-ram and superram intakes. You're right, definitely more bang for the buck and it's definitely the way to go if you're planning future mods (heads, cam, etc.). I'm not planning to do anything major in the near future, so I'm comfortable with modest HP and Torque gains. It looks like a Super/Mini Ram would boost the HP and Torque in the upper RPM range, but I would rather not sacrafice the low end torque. Thanks!!
I've been looking around at the mini-ram and superram intakes. You're right, definitely more bang for the buck and it's definitely the way to go if you're planning future mods (heads, cam, etc.). I'm not planning to do anything major in the near future, so I'm comfortable with modest HP and Torque gains. It looks like a Super/Mini Ram would boost the HP and Torque in the upper RPM range, but I would rather not sacrafice the low end torque. Thanks!!
Burning Brakes
Joined: Nov 2003
Posts: 914
Likes: 1
From: Redding Ca
I had TPIS Big Mouth manifold, Large tube runners and 52MM throttle body (only porting was per TPIS Insider's Hints to the plenum...very easy to do) and the engine was a sweetheart. Tremendous increase in low end to mid range power.
I doubt you will see much improvement in porting the manifold base, I'd just leave it. Once you are on the road again, you will start to focus on the next best things to do. Drag radials for sure!
I doubt you will see much improvement in porting the manifold base, I'd just leave it. Once you are on the road again, you will start to focus on the next best things to do. Drag radials for sure!
Thread Starter
Racer
Joined: Feb 2004
Posts: 445
Likes: 1
From: Atlanta GA
Originally Posted by GeosFun
Tremendous increase in low end to mid range power.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
It sounds like you have a solid plan, good luck.
You might also have an AFPR installed and set to current fuel pressure (have your mechanic measure current pressure at warm idle with the vacuum line off the FPR). Then you can bump fuel pressure to match increased air flow at WOT. Even if you eventually get a custom chip this is a good way to tune now. Summit carries the HyperTech units.
You might also have an AFPR installed and set to current fuel pressure (have your mechanic measure current pressure at warm idle with the vacuum line off the FPR). Then you can bump fuel pressure to match increased air flow at WOT. Even if you eventually get a custom chip this is a good way to tune now. Summit carries the HyperTech units.
Thread Starter
Racer
Joined: Feb 2004
Posts: 445
Likes: 1
From: Atlanta GA
Thanks 65Z01...you're reading my mind with this stuff!!
I already have a Hypertech chip from Summit installed, but would like to talk to Jesse for a custom burn once I get everything installed. I'm planning to order a BBK Adjustable Fuel Pressure Regulator from Summit ($59.99 vs. $89.99 for the TPIS model), and I'll pass your suggestion on to the mechanic RE: setting the pressure.
A year ago, I knew very little about my L98 Vette. Now, thanks to you guys, I think I have a pretty good idea of how to accomplish what I'm shooting for. Thanks Again!!
I already have a Hypertech chip from Summit installed, but would like to talk to Jesse for a custom burn once I get everything installed. I'm planning to order a BBK Adjustable Fuel Pressure Regulator from Summit ($59.99 vs. $89.99 for the TPIS model), and I'll pass your suggestion on to the mechanic RE: setting the pressure.
A year ago, I knew very little about my L98 Vette. Now, thanks to you guys, I think I have a pretty good idea of how to accomplish what I'm shooting for. Thanks Again!!
Racer
Joined: May 2002
Posts: 354
Likes: 0
From: Beach Cities SoCal
While the intake is off I'd also replace the EGR valve.
I have a stock '90...I'm going this route:
52mm TB
Edelbrock High Flo TPI Intake Base and runners
SVO 24lb injectors
AFPR
New EGR valve
3" exhaust leading to a high flow cat (Already have Super Turbo mufflers and 3" rear y.
Then I'll know if I need the
SR
Cam
Heads
RR
Headers (probably won't go with them though)
I have a stock '90...I'm going this route:
52mm TB
Edelbrock High Flo TPI Intake Base and runners
SVO 24lb injectors
AFPR
New EGR valve
3" exhaust leading to a high flow cat (Already have Super Turbo mufflers and 3" rear y.
Then I'll know if I need the
SR
Cam
Heads
RR
Headers (probably won't go with them though)
Last edited by Ivory90; May 2, 2005 at 02:46 PM.
