Building a sub-5s 0-60 L98
#1
Intermediate
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Building a sub-5s 0-60 L98
Hello everyone. I've been doing a LOT of reading and researching in an effort to find out what it would take to make a '91 C4 competitive with a base C6 or C7... and that seems to be 450 hp or thereabouts. I'd be starting with a L98, and thinking I'd need to rebuild it into a 383 stroker, get the factory heads ported, get a mild but decent cam and 1.6" rockers, and throw on a FIRST TPI manifold and headers along with a good exhaust, e.g., Corsa. With the factory D44 rear end and 6-speed, am I in the ball park? I figure this would be about a $5K build give or take... is that right? I want something that looks very much like stock upon first glance under the hood, but that runs like stink. Could I get by with the factory TPI but with large tube ASM runners, perhaps the Edelbrock manifold, have the plenum ported and the runners and baseplate extrude-honed? Comments?
Last edited by obijohnkenobe; 04-04-2019 at 02:39 AM.
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yakmastermax (03-26-2024)
#2
Le Mans Master
Budget a little low unless you have access to a machine shop and ability to do most or all of the work. Getting there by going carb and a little luck searching used racing part sites. A 3.73 -4.33 gear will be helpful. You should be able to meet your goals. Tuning factory efi canbe time consuming and expensive. Stand alone efi can eat up half your budget. Nitrous Oxide another option.
#3
Le Mans Master
You could probably get low 5s on the stock unit... but if you are trying to increase the usuable power band then it really shouldn't matter all to much going to something like the first... you'll get a mild boost up top compared to stock. The important thing is making sure to match all the parts. If you do a 383 use decent heads... the factory ported may get you there but you can do much better just bolting on imo and then you don't have to worry about having all the extra work done. Work the exhaust some use a mild cam in the 220s duration. It will be very drivable and pull well. Having the extra torque down low will make you launch better as well... so long as you can put the power down that is. You're on the right track.
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obijohnkenobe (04-09-2019)
#4
Drifting
383, Mini Ram, AFR Heads, Bigger Injectors, 220/220-ish cam, larger fuel pump, larger injectors, headers, high flow cats, 3.73 gear. Still may not get there, but this should be in the 400-450hp.
You are asking to near double your output, it won't be easy.
Just to get it to perform like an LT1 will require Head work, injectors, and a manifold change... getting into C7 territory...You would probably be money ahead to start with a C5 unless you are tied to the C4 or TPI for another reason. Remember, the TPI was designed to make a lot of torque and feel strong in normal driving conditions. It is not a high RPM/High HP system. The FAST system flows well but still will not outperform a short runner intake above 4500RPMS.
You are asking to near double your output, it won't be easy.
Just to get it to perform like an LT1 will require Head work, injectors, and a manifold change... getting into C7 territory...You would probably be money ahead to start with a C5 unless you are tied to the C4 or TPI for another reason. Remember, the TPI was designed to make a lot of torque and feel strong in normal driving conditions. It is not a high RPM/High HP system. The FAST system flows well but still will not outperform a short runner intake above 4500RPMS.
#5
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My 88 will run with my 2019, traction becomes a problem with the torque I make. You will need pretty good tires, but new cars are more efficient at putting engine power to the ground. Top end, the 2019 will pull away, and will always feel more stable. Gun my 88 and she might go sideways.
398 Superram, AFR 195 heads, Crane Gold 1.6RR, Crower cam, TPiS headers, true dual exhaust. I have between 10-12K in the engine alone. Traction will be just as much a problem with the FIRST if you choose that intake, and I don't think the FIRST will have any success after 60mph.
398 Superram, AFR 195 heads, Crane Gold 1.6RR, Crower cam, TPiS headers, true dual exhaust. I have between 10-12K in the engine alone. Traction will be just as much a problem with the FIRST if you choose that intake, and I don't think the FIRST will have any success after 60mph.
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obijohnkenobe (04-09-2019)
#6
Safety Car
Hello everyone. I've been doing a LOT of reading and researching in an effort to find out what it would take to make a '91 C4 competitive with a base C6 or C7... and that seems to be 450 hp or thereabouts. I'd be starting with a L98, and thinking I'd need to rebuild it into a 383 stroker, get the factory heads ported, get a mild but decent cam and 1.6" rockers, and throw on a FIRST TPI manifold and headers along with a good exhaust, e.g., Corsa. With the factory D44 rear end and 6-speed, am I in the ball park? I figure this would be about a $5K build give or take... is that right? I want something that looks very much like stock upon first glance under the hood, but that runs like stink. Could I get by with the factory TPI but with large tube ASM runners, perhaps the Edelbrock manifold, have the plenum ported and the runners and baseplate extrude-honed? Comments?
-355 or 383 will work
-Cast crank since you are not reving it to the moon with a First or TPI intake, assume a 6000 RPM or earlier shift
-Stock rods will be fine
-Forged pistons would be nice in the 10.25 to 10.5 CR range. Hypers would be OK but forged would be my choice.
-Assembly the engine yourself
-Add long tube headers
-Stock heads ported (maybe but if you have to pay someone it may be better to buy some aftermarket heads like trick flow or others that are similar) $1000 for heads goes a long way these days, that would probably be the porting cost
-Hyd roller cam like the ZZ9 or Hot cam, or work with someone to come up with a newer custom grind that has faster ramps for better power but still designed for good TPI performance
-30 lb injectors and a tune
-First would probably be the cheapest with the best power potential, a TPI with aftermarket base and runners may cost more then the first and have less potential. (look for used could be your best bet) I assume you wnat the TPI look so I have ruled out the Superram or Mini ram
-1.5 or 1.6 rockers are fine, if you spec the cam correctly either rocker can be used. (In other words target the lift you want and get a cam to do that with 1.5 rockers) If you need more lift from an off the shelf grind then use 1.6 rockers
One more comment, if your stock engine is good use it! The 350 willl get your goals with heads, cam, intake, headers and tune. (Saves money)
This combination should be around 350 to 400 HP (maybe more) and it will run hard.
I had a 355 with a Large tube TPI combination and it ran hard, 300 HP to the tires, around 360 HP at the crank and the car ran high to mid 12's at 108 MPH in the 1/4. Not 450 HP but ET wise was close to the new cars.
Last edited by bjankuski; 04-04-2019 at 09:23 AM.
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Mike Holmen (04-07-2019)
#8
a stock 91 6 speed coupe generally runs 0-60 in the mid-high 5 second range if you compare apples to apples stock LS3 C6 manual and C7 LT1 manual coupes are hitting low 4’s high 3’s figure abut TWO full seconds against a Z51 Manual Stingray in the 1/4 you’re talking about a car that traps around 100 with a car that can trap close to 120 SURPISING a poorly driven one at the stoplight with some 3.73’s, drag radials and FULL bolt ons can be done but hitting 120 in the 1/4 isn’t going to happen with a streetable LONG RUNNERED N/A TPI
Last edited by Y-bodluvr; 04-04-2019 at 10:14 AM.
#9
Le Mans Master
My 88 will run with my 2019, traction becomes a problem with the torque I make. You will need pretty good tires, but new cars are more efficient at putting engine power to the ground. Top end, the 2019 will pull away, and will always feel more stable. Gun my 88 and she might go sideways.
398 Superram, AFR 195 heads, Crane Gold 1.6RR, Crower cam, TPiS headers, true dual exhaust. I have between 10-12K in the engine alone. Traction will be just as much a problem with the FIRST if you choose that intake, and I don't think the FIRST will have any success after 60mph.
398 Superram, AFR 195 heads, Crane Gold 1.6RR, Crower cam, TPiS headers, true dual exhaust. I have between 10-12K in the engine alone. Traction will be just as much a problem with the FIRST if you choose that intake, and I don't think the FIRST will have any success after 60mph.
#11
Drifting
a stock 91 6 speed coupe generally runs 0-60 in the mid-high 5 second range if you compare apples to apples stock LS3 C6 manual and C7 LT1 manual coupes are hitting low 4’s high 3’s figure abut TWO full seconds against a Z51 Manual Stingray in the 1/4 you’re talking about a car that traps around 100 with a car that can trap close to 120 SURPISING a poorly driven one at the stoplight with some 3.73’s, drag radials and FULL bolt ons can be done but hitting 120 in the 1/4 isn’t going to happen with a streetable LONG RUNNERED N/A TPI
You can surprise a lot of people with more power using a well tuned chassis that gets the first 60' and 100' down well.
Another Example... Tesla P100D Model S versus a Hellcat. In the 1/4 mile the torque and traction trumps the Hellcat's power. The extra horsepower in the Heelcat shows in trap speed... but the Tesla gets there first. Many TPI builds have got into the 11s using long(ish) runners.
A very wise old drag racer once told me you build a car from the back to the front, because all the power in the world means nothing if you can't put it to the pavement.
Last edited by KyleF; 04-04-2019 at 11:41 AM.
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obijohnkenobe (04-09-2019)
#12
Drifting
Because by the time you have a functional LS in there, you are way past $5k. Especially if you want all your dash functions working.
Last edited by KyleF; 04-04-2019 at 11:43 AM.
#13
it can be done much cheaper. Def not worth it spending $5k on some archaic set up in my opinion at least.
Last edited by slow_zo6; 04-04-2019 at 02:03 PM.
#14
People worry about trap speed too much. It is irrelevant, a drag race is about time, not speed. Reaction time and ET. Ever seen a top fuel dragster blow its tires off mid track and shut down? ET around 6 seconds and a trap of 150mph? Still got there in 6 seconds.
You can surprise a lot of people with more power using a well tuned chassis that gets the first 60' and 100' down well.
. Many TPI builds have got into the 11s using long(ish) runners.
You can surprise a lot of people with more power using a well tuned chassis that gets the first 60' and 100' down well.
. Many TPI builds have got into the 11s using long(ish) runners.
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#15
Drifting
You are not getting a 450hp LS in there maintaining all vehicle functionality for $5k. I have looked into it as an option and as with most swaps, it is a lot more involved than most give it credit for. I will say there are advantages to go LS, but there are some hurdles. If you are referring to getting a junk yard LS1/LS2... that's a roll of the dice too. However, if you see above I mentioned just starting with a C5 for this reason. I still believe you would be money ahead if you want to do an LS by selling the C4, buying a C5 and start from there.
#16
Even though there was no C6 yet Im sure it would have given an LS2 2.73 geared automatic convertible FITS
Last edited by Y-bodluvr; 04-04-2019 at 03:09 PM.
#17
Le Mans Master
You are not getting a 450hp LS in there maintaining all vehicle functionality for $5k. I have looked into it as an option and as with most swaps, it is a lot more involved than most give it credit for. I will say there are advantages to go LS, but there are some hurdles. If you are referring to getting a junk yard LS1/LS2... that's a roll of the dice too. However, if you see above I mentioned just starting with a C5 for this reason. I still believe you would be money ahead if you want to do an LS by selling the C4, buying a C5 and start from there.
I agree
FWIW I have a 462rwhp running through a 3000 stall converter, and minus headers (already had) tune and injectors, I have about $5,000. in it. RKLESSDRIVER built it for me. With careful pricing it can be done. For that money I have a 4 bolt splayed block, forged rotating assy, AFR heads, Mike Jones Cam, etc. On the first day to the track, it ran an 11.19 at 124.6 mph with a soft 1.60 60ft.
Your not going to get that out of a $5,000.00 LS conversion unless you add Nitrous, or a blower. I may be wrong, and if I am, show it too me.
But, to the OP if 0 to 60 is your only concern, put a low gear in the rear and a good set of drag radials..... That may be all you need to get a 5 sec. 0 to 60
#18
Drifting
I agree
FWIW I have a 462rwhp running through a 3000 stall converter, and minus headers (already had) tune and injectors, I have about $5,000. in it. RKLESSDRIVER built it for me. With careful pricing it can be done. For that money I have a 4 bolt splayed block, forged rotating assy, AFR heads, Mike Jones Cam, etc. On the first day to the track, it ran an 11.19 at 124.6 mph with a soft 1.60 60ft.
Your not going to get that out of a $5,000.00 LS conversion unless you add Nitrous, or a blower. I may be wrong, and if I am, show it too me.
But, to the OP if 0 to 60 is your only concern, put a low gear in the rear and a good set of drag radials..... That may be all you need to get a 5 sec. 0 to 60
I bought my '84 with the swap already done for $8500. It isn't 462rwhp but it does make 420rwhp with a mild 220/224 .575/.575 cam. That car also came with C5 brake swap, 17" replica C6 Z06 wheels, D44 swap and TKO 600 conversion.
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yakmastermax (03-26-2024)
#19
$3k of LS engine can get you near that power level. It is just whether or not you can get it in the car for the other $2k.
I bought my '84 with the swap already done for $8500. It isn't 462rwhp but it does make 420rwhp with a mild 220/224 .575/.575 cam. That car also came with C5 brake swap, 17" replica C6 Z06 wheels, D44 swap and TKO 600 conversion.
I bought my '84 with the swap already done for $8500. It isn't 462rwhp but it does make 420rwhp with a mild 220/224 .575/.575 cam. That car also came with C5 brake swap, 17" replica C6 Z06 wheels, D44 swap and TKO 600 conversion.
Just be sure to use a 3/4 cam and have the cragars to match. 👌
#20
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Funny thing is these days the c5-7 guys are all using "stage xx" cams, goofy names etc. History repeats itself
LS1 isnt impressive by any means unles someone has really put some work into it. by the time they put say an AFR head, cam, headers tune etc they are going to spend a TON. So the Gen 1 needs a little more cam timing to get there not a big deal. I like the idea of a world block that takes an LS head, add distributor and it bolts in. Kind of an SB2 type engine on the cheap
If anyone remembers mseven he had a big ci SB2.2 with a hyd roller st driven motor that made well over 730chp, not hard to drive at all. Getting off track again..
Lots of LS swaps but one done right isnt cheap.
LS1 isnt impressive by any means unles someone has really put some work into it. by the time they put say an AFR head, cam, headers tune etc they are going to spend a TON. So the Gen 1 needs a little more cam timing to get there not a big deal. I like the idea of a world block that takes an LS head, add distributor and it bolts in. Kind of an SB2 type engine on the cheap
If anyone remembers mseven he had a big ci SB2.2 with a hyd roller st driven motor that made well over 730chp, not hard to drive at all. Getting off track again..
Lots of LS swaps but one done right isnt cheap.
Last edited by cv67; 04-05-2019 at 12:11 PM.
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dclafleur (04-12-2019)