91 L98 What would you do 1st?
Thread Starter
8th Gear
Joined: Apr 2003
Posts: 8
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From: San Diego CA
91 L98 What would you do 1st?
I'm asking this for my Dad. He just got a 91 and its bone stock. What's the first things you guys/gals would do to boost the performance a bit? Any free mods for these cars he should know of? Such as "Remove this", "Rewire that", or "Bypass this". Any help would be great.
I Know, total
question.
[Modified by dlterrones, 9:53 PM 4/16/2003]
I Know, total
question. [Modified by dlterrones, 9:53 PM 4/16/2003]
Team Owner
Joined: Sep 2001
Posts: 62,171
Likes: 1,735
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 91 L98 What would you do 1st? (dlterrones)
The basic problem with the L98 is the intake setup, it was designed for a 305 motor, so the major mod most of us do is to either take it off and port it (open up the holes bigger) or do away with it entirely.
There are a few free mods, bypass the coolant from the Throttle Body, add a lower temperature thermostat (180 or 160), remove the 'frisbee' from the water pump (its a big weight on front of it, serves no purpose).
Also add a K&N filter, and cut open the air lid so the filter is exposed.
Then it will respond very well to full headers and exhaust.
Anything more requires intake changes/modifications.
There are a few free mods, bypass the coolant from the Throttle Body, add a lower temperature thermostat (180 or 160), remove the 'frisbee' from the water pump (its a big weight on front of it, serves no purpose).
Also add a K&N filter, and cut open the air lid so the filter is exposed.
Then it will respond very well to full headers and exhaust.
Anything more requires intake changes/modifications.
Thread Starter
8th Gear
Joined: Apr 2003
Posts: 8
Likes: 0
From: San Diego CA
Re: 91 L98 What would you do 1st? (vader86)
Thanks! Thats exactly the kind of stuff I was looking for.
Do you know of any instructions for the porting with some pictures someware. Some VFAQs or something. I can do the porting for him as long as I know what and where to grind. I havn't opened it up yet.
What is a good place to look for exhaust setups also?
Do you know of any instructions for the porting with some pictures someware. Some VFAQs or something. I can do the porting for him as long as I know what and where to grind. I havn't opened it up yet.
What is a good place to look for exhaust setups also?
Team Owner
Joined: Sep 2001
Posts: 62,171
Likes: 1,735
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 91 L98 What would you do 1st? (dlterrones)
You can get Hooker headers from Jegs or Summit Racing, TPiS and Lingenfelter.com both make a set.
Catback setups, from Ecklers or MidAmerica. Stuff like Borla, B&B, Power Effects...
Catback setups, from Ecklers or MidAmerica. Stuff like Borla, B&B, Power Effects...
Melting Slicks
Joined: Apr 2002
Posts: 2,308
Likes: 1
From: Portsmouth VA
Re: 91 L98 What would you do 1st? (scorp508)
full exhaust makes a HUGE difference on the L98's
do all the free/cheap stuff already described (and a cooler fan switch to go with that lower thermostat).
get somebody to make you a custom chip.
roller rockers. switch to 1.6 roller rockers... they are a good bang for buck item.
auto or stick? if auto you can mess with the tranny to get big performance increases. never had an auto so i don't know that much about that, but there are loads of guys here that do.
do all the free/cheap stuff already described (and a cooler fan switch to go with that lower thermostat).
get somebody to make you a custom chip.
roller rockers. switch to 1.6 roller rockers... they are a good bang for buck item.
auto or stick? if auto you can mess with the tranny to get big performance increases. never had an auto so i don't know that much about that, but there are loads of guys here that do.
Drifting
Joined: Feb 2002
Posts: 1,937
Likes: 2
From: Arvada CO
Re: 91 L98 What would you do 1st? (dlterrones)
Ok...this is what i did when i bought mine! i did it all in like 1 week!
1. cut out the pre cats up front (stock exhaust manifold)
2. cut off the mufflers and ran 3 inch from middle cat to Z28 stock tips (no muffs)
3. cut the lid and go K&N (i have one cut with K&N for sale so your old man can always go back to stock)
4. Coolent bypass on TB (throttle body)
5. Wire 8.5 MSD's and MSD Box 6a and coil for HEI
6. Diff gears went from 2:59 to 3:73 (strange racing gears)
That right there was fast enough for the mean time then i went a step further......
7. ditched the exhaust manifolds to Headman Headers full length (get them jet coated will run really hot under the hood)
8. ran 3 inch (from headers) to y pipe 4 inch to cat then 4 inch out to Y pipe to 3 inch to stock Z28 tips.
9. NOS wet kit (150 shot)
Ran that for awhile then i got a blower and it keeps going on and on!
But i would say go with the typical stuff that everyone is saying write them all down and do them all at one time and then a chip burned from i would say Ed Write at Fast chips...
Get a dyno from a before (Stock) and an After (modded) and then get the dyno print out and get a chip burned from that information on the modded!
I would say that will do for now!
:steering: :steering: :steering:
1. cut out the pre cats up front (stock exhaust manifold)
2. cut off the mufflers and ran 3 inch from middle cat to Z28 stock tips (no muffs)
3. cut the lid and go K&N (i have one cut with K&N for sale so your old man can always go back to stock)
4. Coolent bypass on TB (throttle body)
5. Wire 8.5 MSD's and MSD Box 6a and coil for HEI
6. Diff gears went from 2:59 to 3:73 (strange racing gears)
That right there was fast enough for the mean time then i went a step further......
7. ditched the exhaust manifolds to Headman Headers full length (get them jet coated will run really hot under the hood)
8. ran 3 inch (from headers) to y pipe 4 inch to cat then 4 inch out to Y pipe to 3 inch to stock Z28 tips.
9. NOS wet kit (150 shot)
Ran that for awhile then i got a blower and it keeps going on and on!
But i would say go with the typical stuff that everyone is saying write them all down and do them all at one time and then a chip burned from i would say Ed Write at Fast chips...
Get a dyno from a before (Stock) and an After (modded) and then get the dyno print out and get a chip burned from that information on the modded!
I would say that will do for now!
:steering: :steering: :steering:
Thread Starter
8th Gear
Joined: Apr 2003
Posts: 8
Likes: 0
From: San Diego CA
Re: 91 L98 What would you do 1st? (dlterrones)
Thanks guys. Lots of good info that will be put to good use. I dont know how far hes willing to go with this car. But if it goes anything like me and my car it will snowball forever. :D You know how it is.
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Drifting
Joined: Jul 2001
Posts: 1,751
Likes: 1
From: Miami, FL, USA
Re: 91 L98 What would you do 1st? (dlterrones)
The free stuff is okay, but just remember, in life and in motorsports....
YOU GET WHAT YOU PAY FOR, and SPEED COSTS MONEY
I would put the Hooker 2149s with the 16720 Y-Pipe, and then go with the best Catback you can afford, Borla, Flowmaster, Power Effects, B&B, Corsa, or even Hooker now.
The exhaust really helps. Also, if you are auto and have the 2.59 rear end, go to the 3.07.
Do the K&N open lid, and save up for a head\cam\intake combo.
The free stuff is just like all the other free stuff.....trust me, you do not gain 5 HP from a TB bypass, or 10 HP from removing the frisbee, and relocating the IAT actually may hurt more than help!
I also recommend tuning it up completely, these cars can be real dogs when they are out of tune. Mine was a new beast after I did a full tune up.
Change the plugs to NGK TR-55, new wires, cap, coil, rotor, set timing to 6 deg (DO NOT ADVANCE ANY HIGHER!), a new Fuel filter does wonders. Run 93-94 octane only. You will be happy.
YOU GET WHAT YOU PAY FOR, and SPEED COSTS MONEY
I would put the Hooker 2149s with the 16720 Y-Pipe, and then go with the best Catback you can afford, Borla, Flowmaster, Power Effects, B&B, Corsa, or even Hooker now.
The exhaust really helps. Also, if you are auto and have the 2.59 rear end, go to the 3.07.
Do the K&N open lid, and save up for a head\cam\intake combo.
The free stuff is just like all the other free stuff.....trust me, you do not gain 5 HP from a TB bypass, or 10 HP from removing the frisbee, and relocating the IAT actually may hurt more than help!
I also recommend tuning it up completely, these cars can be real dogs when they are out of tune. Mine was a new beast after I did a full tune up.
Change the plugs to NGK TR-55, new wires, cap, coil, rotor, set timing to 6 deg (DO NOT ADVANCE ANY HIGHER!), a new Fuel filter does wonders. Run 93-94 octane only. You will be happy.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: 91 L98 What would you do 1st? (dlterrones)
Check out the "free" and other mods on my site and then the results of L98 mods page for a complete recipe for a 12sec L98.
Indeed do all the "free" stuff, then the exhaust. If he isn't into LT headers, do the mandrel bent front Y.
When it comes to intake mods you can mod the TPI or go to a mini-ram or super-ram setup.
Some real power can be had from porting the stock #113 heads and doing a nice cam.
Don't do a chip change right away, install an AFPR and use it to add fuel as you increase air flow through the engine.
If it has an A4 tranny it will benefit from a TransGo shift kit and a 2,000rpm TC.
Have fun doing the mods and "test driving" his new Vette.
Oh, and remind him to save the wave.
Indeed do all the "free" stuff, then the exhaust. If he isn't into LT headers, do the mandrel bent front Y.
When it comes to intake mods you can mod the TPI or go to a mini-ram or super-ram setup.
Some real power can be had from porting the stock #113 heads and doing a nice cam.
Don't do a chip change right away, install an AFPR and use it to add fuel as you increase air flow through the engine.
If it has an A4 tranny it will benefit from a TransGo shift kit and a 2,000rpm TC.
Have fun doing the mods and "test driving" his new Vette.
Oh, and remind him to save the wave.
Thread Starter
8th Gear
Joined: Apr 2003
Posts: 8
Likes: 0
From: San Diego CA
Re: 91 L98 What would you do 1st? (GusBustamanteJr)
The free stuff is okay, but just remember, in life and in motorsports....
YOU GET WHAT YOU PAY FOR, and SPEED COSTS MONEY
The free stuff is just like all the other free stuff.....trust me, you do not gain 5 HP from a TB bypass, or 10 HP from removing the frisbee, and relocating the IAT actually may hurt more than help!
I also recommend tuning it up completely, these cars can be real dogs when they are out of tune. Mine was a new beast after I did a full tune up.
YOU GET WHAT YOU PAY FOR, and SPEED COSTS MONEY
The free stuff is just like all the other free stuff.....trust me, you do not gain 5 HP from a TB bypass, or 10 HP from removing the frisbee, and relocating the IAT actually may hurt more than help!
I also recommend tuning it up completely, these cars can be real dogs when they are out of tune. Mine was a new beast after I did a full tune up.
Run 93-94 octane only. You will be happy.
Team Owner
Joined: Sep 2001
Posts: 62,171
Likes: 1,735
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 91 L98 What would you do 1st? (dlterrones)
Oh, and remind him to save the wave.
What :confused:
What :confused:
And youll need to go into your profile and set the default to show members' sigs. Its useful in the Tech sections since most people have links or power numbers.
Thread Starter
8th Gear
Joined: Apr 2003
Posts: 8
Likes: 0
From: San Diego CA
Re: 91 L98 What would you do 1st? (vader86)
Thanks.
If i could get my dad to use the computer for more than just an elcectronic pinball machine I would have him post for himself. HEHE.
If i could get my dad to use the computer for more than just an elcectronic pinball machine I would have him post for himself. HEHE.
Drifting
Joined: May 2002
Posts: 1,581
Likes: 2
From: The Motor City
Re: 91 L98 What would you do 1st? (dlterrones)
I guess nobody's explained it to you yet. Either that or you just haven't experienced it yet.
For years, Corvette drivers have ALWAYS waved when they passed each other on the street. But, with the introduction of the C4, many owners of previous generations began complaining that C4 drivers didn't wave back.
It was believed that the C4 was attracting 'yuppie-like' customers that stuck their noses in the air towards anyone who drove 'the old car' and so they would never waved back. That was the theory anyway. I personally believe that the car just attracted alot of customers that just weren't used to having total strangers wave at them because of the car they drove.
Regardless of the reason, in an effort to keep this 'snobbish behaviour' from spreading any further a movement amongst the Corvette community was started a few years ago to keep Corvette drivers waving at each other. Soon after it's inception, it adopted the now farmiliar slogan "SAVE THE WAVE".
And we've all been saying it ever since.
Welcome (to you and your dad) to the club. :seeya
For years, Corvette drivers have ALWAYS waved when they passed each other on the street. But, with the introduction of the C4, many owners of previous generations began complaining that C4 drivers didn't wave back.
It was believed that the C4 was attracting 'yuppie-like' customers that stuck their noses in the air towards anyone who drove 'the old car' and so they would never waved back. That was the theory anyway. I personally believe that the car just attracted alot of customers that just weren't used to having total strangers wave at them because of the car they drove.
Regardless of the reason, in an effort to keep this 'snobbish behaviour' from spreading any further a movement amongst the Corvette community was started a few years ago to keep Corvette drivers waving at each other. Soon after it's inception, it adopted the now farmiliar slogan "SAVE THE WAVE".
And we've all been saying it ever since.
Welcome (to you and your dad) to the club. :seeya