runners.. Ported SLP or Stock
Thread Starter
Instructor
Joined: Jun 2013
Posts: 225
Likes: 1
From: hanceville al
runners.. Ported SLP or Stock
Hey all,
I'm about to have my plenum ported and lower manifold ported as well. I need some advice on the runners, should I have the stock ones ported or buy the SLP's and have them ported. Can I acheive close to the same performance gains with stock ported runners as to the ported SLP runners? There was a memeber that said you could not port the stock ones I talked with the fellow that is about to do the work and he reassured me you could. Any one else out there have any info. Also I have decieded to go with the 52mm throttle body. all,
I'm about to have my plenum ported and lower manifold ported as well. I need some advice on the runners, should I have the stock ones ported or buy the SLP's and have them ported. Can I acheive close to the same performance gains with stock ported runners as to the ported SLP runners? There was a memeber that said you could not port the stock ones I talked with the fellow that is about to do the work and he reassured me you could. Any one else out there have any info. Also I have decieded to go with the 52mm throttle body. all,
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
Hey all,
I'm about to have my plenum ported and lower manifold ported as well. I need some advice on the runners, should I have the stock ones ported or buy the SLP's and have them ported. Can I acheive close to the same performance gains with stock ported runners as to the ported SLP runners? There was a memeber that said you could not port the stock ones I talked with the fellow that is about to do the work and he reassured me you could. Any one else out there have any info. Also I have decieded to go with the 52mm throttle body. all,
I'm about to have my plenum ported and lower manifold ported as well. I need some advice on the runners, should I have the stock ones ported or buy the SLP's and have them ported. Can I acheive close to the same performance gains with stock ported runners as to the ported SLP runners? There was a memeber that said you could not port the stock ones I talked with the fellow that is about to do the work and he reassured me you could. Any one else out there have any info. Also I have decieded to go with the 52mm throttle body. all,
Thread Starter
Instructor
Joined: Jun 2013
Posts: 225
Likes: 1
From: hanceville al
Got the long tubes, cat deletes, x pipe and performance mufflers, along with some engine work cam, bigger valves, just need to let her breath better, I havent seem that maniflod I will look into it thanks!
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
These aftermarket intake manifolds are ridiculously expensive. I kept my cool and was patient in looking. I found a used Edelbrock 3860 from a junk yard in FL for $150 shipped to Mesa AZ. The SLP runners I also bought used for $170 delivered. Well worth the wait as money isn't so easy to come by for me. I didn't lose any torque. I bought the Comp cam 08-501-8 and sadly NOBODY ever talks about this cam. I bought the guide plates rods springs everything from Comp Cam. Their tech support advised me in this choice. I haven't spent a dime on any tuning. I ported the heads exhaust a little bit and gasket matched everything. Ported the plenum myself no trick there just cut out the middle and left 4 big holes in the plenum. I have yet to max it out as it is considerably more powerful. I bought 1.5 roller rocker arms. My 1988 ECM runs the engine perfect. If anything my idle is different. A little choppy but stays at a steady 600 in gear and 700 in park. I have only jammed on the gas once at a green light change and it went sideways. So no torque loss. After it hits 135 the gains are slower but steady none the less. I dont have the ***** to max it out. I will get arrested going 150+ or killed.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
I have been told all these aftermarket runners are better than the stock ! With that said I let the cost be the deciding factor. All I can go by are the ones I own and use the SLP runners. I can say a heck of allot of aluminum was ported out of my runners. Remember the gears are a factor unless your car is a stick shift ? Mine is an automatic 2:73 Dana 36. Not a car to be trying to win races in. I find my car to be better at top end where it seems to have lots of power.
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Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
You seem like a cool dude who is all excited about his 1990 C4. I admit your car is a better year than my 1988. Please keep this in mind. DO NOT SPEND TOO MUCH MONEY on that car. Keep it to a minimum and save for a 2002-2004. I have sunk $17,000 cash into my money pit. Right now I could be driving a 345HP stock C5 that breaths and does 180mph top speed. Great gas mileage the list goes on and on. For the kinda cash I have wasted on my car I could own and drive a Z06.
Instructor
Joined: Apr 2011
Posts: 127
Likes: 0
You seem like a cool dude who is all excited about his 1990 C4. I admit your car is a better year than my 1988. Please keep this in mind. DO NOT SPEND TOO MUCH MONEY on that car. Keep it to a minimum and save for a 2002-2004. I have sunk $17,000 cash into my money pit. Right now I could be driving a 345HP stock C5 that breaths and does 180mph top speed. Great gas mileage the list goes on and on. For the kinda cash I have wasted on my car I could own and drive a Z06.
Having been there many times myself, I say do what you want with it. You are going about it right, and other than a few trolls, there are a wealth of people on here that will stop at nothing to help you any way they can.
Speaking from experience on my last build, set a goal with your ride, and upgrade according to that goal, and you wont double spend on a mod. If you are going to put a cam in it, and open up the exhaust (higher flow), you will want to do the same with the intake. That said, you will like the bigger throttle body and the bigger runners and if/when you do a bigger cam and/or 1:6 rockers, then you will have the intake / exhaust to accomodate it. You will REALLY feel it when you switch the rear end gears. The engine won't run out of breath and you'll love the red light / red light ride
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
There was a memeber that said you could not port the stock ones I talked with the fellow that is about to do the work and he reassured me you could
Ask for proof you can cause youll never see it.
Last edited by cv67; Jun 9, 2013 at 11:28 PM.
Advanced
Joined: Jan 2012
Posts: 84
Likes: 0
From: Jacksonville NC
I don't know about SLP, but I have the Big Mouth base and either AS&M or TPIS runners on mine. There is no way you could port out the stock ones to this size. Here's some pictures to compare:
Stock runners
Large runners
Stock on the right
Stock runners
Large runners
Stock on the right
Thread Starter
Instructor
Joined: Jun 2013
Posts: 225
Likes: 1
From: hanceville al
OK thats what I'm talking about, great info, thanks to all for there comments! Now I know I dont want to go stock so aftermarket it is. SLP, Edelbrock, any others out there any major besides price between them?
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 413
From: WV
SLPs have the most "meat" on them if you want to port them to there max..Im running Accel runners , they had a 1 3/4" hole before I ever started porting them, plus you can pick these up alot cheaper sometimes......WW
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 110
From: Austin Texas
Here's a direct side by side between the stock runners and TPIS's version...stock on right.
Here's my build site ...I'm now over 425 FWHP and 535 FWTQ from a TPI...
I went with the TPIS runners because I didn't want to advertise that I had completely modded the motor. Open the hood and it "looks" stock...but sure doesn't run like stock.
Here's my build site ...I'm now over 425 FWHP and 535 FWTQ from a TPI...
I went with the TPIS runners because I didn't want to advertise that I had completely modded the motor. Open the hood and it "looks" stock...but sure doesn't run like stock.
Last edited by 1991Z07; Jun 10, 2013 at 09:25 AM.
Le Mans Master
Joined: Aug 2007
Posts: 8,735
Likes: 413
From: WV
That's why I went with the Accel runners, they look stock except they are a little fatter...
..I also got one of the last 'Mega Ported Plenums' before Mike Graycar closed his business "Corvette Plenums"....
....WW
..I also got one of the last 'Mega Ported Plenums' before Mike Graycar closed his business "Corvette Plenums"........WW
Last edited by WW7; Jun 10, 2013 at 10:32 AM.
Thread Starter
Instructor
Joined: Jun 2013
Posts: 225
Likes: 1
From: hanceville al
That looks great I'm leaning toward the edlebrock runners and base. I also want a port and match job on the plenum, runners and base. Top it of with a new 52mm TB. I still am awaiting comments from other members ready to chime in with info before committing.
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
TB will only increase your perception of throttle response at low throttle angles (it will make low throttle adjustments, more "touchy")...but won't help WOT performance in a meaningful way. Spend that money on something that WILL improve actual power/performance.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
If you can't port yourself, find a set of TPIS or AS&M runners. Skip the new throttle body -- as others have already mentioned. It's a TOTAL waste for what you're doing. Total waste, get it?
If you've already bought one, resell it. You need 400rwhp before considering it. You'll be sniffing 300 when you're done....maybe. Even with your cam...If it's an automatic..without a tune, might be more like 270-280. But, that's still a nice bump over stock. It'll feel more like an LT car.
If you've already bought one, resell it. You need 400rwhp before considering it. You'll be sniffing 300 when you're done....maybe. Even with your cam...If it's an automatic..without a tune, might be more like 270-280. But, that's still a nice bump over stock. It'll feel more like an LT car.
Last edited by GREGGPENN; Jun 10, 2013 at 01:52 PM.