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I think you went the right way, open the exhaust up. a small cam with 1.6 roller rockers and a Mini-Ram and you will perform equal to an LT4.
the LT4 hotcam works well. the Mini-Ram actually makes more HP than a LT1 intake. If you could afford it the 185/195cc AFR heads would be the killer combo.
Then your 89 would be awesome...my dream car as well, only 89 with the LCD dash and the MASS Air sensor, Bigger brakes, Dana44, 6SP Maunal.
The rear bumper is suppose to be an aero dynamic feature that creates a vortex, as the1985 with just 230hp the car is capable of 150mph. not many cars can boast that top speed with only 230HP!!!
Does this car not have the Dana 44? I thought all the 6 speed cars had Dana 44s. Bigger brakes?
First mods will just be true dual exhaust. Long tube headers, cat and muffler delete. Then smog provision deletes then maybe an initial tune or chip. Then the next set of mods would be either the First TPI intake and or a set of AFR 195 heads. People have said that a cam swap isn't too hard to do while leaving the motor in the car. Is this true? I'm sure the radiator has to be pulled.
It all depends on what you are looking for. The L98 is a torque monster from idle up where the other one builds more torque at the top end. Don’t let the HP numbers of the L98 fool you. These cars have enough get up and go for most especially if you are going to put headers ( long tube ) on it. Makes a real difference in seat of the pants feel.
good luck with your decision
Good choice. I have a 1990 6 speed. I really wanted an 89 because I like that interior better. I've had the 6 speed with every engine one came with except the LT4. They are all a lot of fun. Hard to rank them though. The ZR1 was awesome once it was wound up. I don't really remember a lot of difference between the 93 LT1 and 90 L98 other than running the RPM's up a little more. But I had the ZR1 and the 93 at the same time so the lt1 didn't really seem that great in comparison. Long story short I don't think you can go wrong with the 6 speed. As far as the engine looks. LT5 is the best looking, followed by L98, then LT1.
TPI motor is the prettiest motor every produced. I'm doing my injectors now. The OEM injectors are short lived.
LT1 Motor, I never never had an opti spark problem. 140,000 miles, still OEM opti. 6 water pumps, yes, but the opti lives. I wouldn't worry about an opti.
TPI motor is the prettiest motor every produced. I'm doing my injectors now. The OEM injectors are short lived.
LT1 Motor, I never never had an opti spark problem. 140,000 miles, still OEM opti. 6 water pumps, yes, but the opti lives. I wouldn't worry about an opti.
Pulled the trigger and put a down payment on a 1989 red on red leather with 55k miles. 6 speed ZF manual and the L98 TPI. Legitimately my dream car for a while now. The only thing that would make it better would be if it had the Z51 suspension package (but not FX3). It has the base suspension, which I think will be fine.
I'm very excited to go pick it up.
It was a bit more than I wanted to spend, but I am happy that I pulled the trigger on something that in reality checked almost all of my boxes and that I didn't compromise. My personal preference is the L98, Red on red, 6 speed, and the Star Wars dash, and that is what I'm getting.
I really am just excited and grateful!
Is there a way to estimate how many cars similar to mine were produced in 1989?
It looks like there were around 4,100 cars in 1989 with the 6 speed manual out of ~26,000 cars total, so around 16% , and around 4760 bright red coupes so also around 16%
So maybe around 750 cars total in 1989 were bright red coupes with 6 speed manuals?
Welcome to the 89 Club….Nice looking ride!!
Enjoy the Car!!
If you consult a gear chart and input the correct trans ratios and accurate tire height ~24.9", you will see that the 3.54 ratio is not really good for anything considering a stock L98's 4300 rpm hp peak. 3.33 isn't much better. Strangely, 3.07 appears to be about ideal. Chevy never really got the ratios right in the 6 speed L98s. The 4+3 with 0.68 OD (Z51) and 3.07 gear was pretty close to ideal. 3.54 does have a nice ring to it, though. LT1 and ZR1 cars probably should've had even more gear.
If you consult a gear chart and input the correct trans ratios and accurate tire height ~24.9", you will see that the 3.54 ratio is not really good for anything considering a stock L98's 4300 rpm hp peak. 3.33 isn't much better. Strangely, 3.07 appears to be about ideal. Chevy never really got the ratios right in the 6 speed L98s. The 4+3 with 0.68 OD (Z51) and 3.07 gear was pretty close to ideal. 3.54 does have a nice ring to it, though. LT1 and ZR1 cars probably should've had even more gear.
With the zf6 3.54s are about the best ratio. First gear in the zf6 is a 2.66 ratio which is not low enough, especially for 3.07s. 6th is .5 which is a lot of overdrive. 1st gear and 3.07s with a zf6 would feel like you're starting off in 2nd or even 3rd gear. Then having the .5 o/d with 3.07s you would be at 1100-1200 rpm doing 65 which the engine would not have enough torque to keep it moving at that speed. My 92 with a LT1 6 speed 3.45s does 1600 RPM at 65. If I go up a slight hill I have to downshift into 5th. I have thought about the 3.54s myself and feel that little extra gear could help it be in a better power range in 6th doing 65-70 on the freeway. 80 up the same hill in 6th is no problem. No need to downshift.
I’ve had my 89 Corvette coupe for over 20 years. Drove my wife to the hospital to deliver our twins in it, they just turned 20 last month. (yes still married too!)
I still love this Corvette!
When I bought it I was still heavily into Autocrossing which is why I bought this specific one. It literally has every option except B2K & the block heater. So all the high performance options including the 6speed manual trans which I love as much as the sport seats that can squeeze you tightly.
Unfortunately the poor girl has been idle for over 10 years now. I had one injector go bad & then parked her as life & other cars took priority. Around a month ago it was finally her time, so apart she came. After sitting idle for so long there’s a whole bunch more I’m doing to make sure she’s 100% when done. With only 72k miles on her, I’m debating about replacing the timing chain & gears since the water pump is off & it’s so close. Other than a cat back Exhaust, she’s all stock & original but it’s hard not to want to do cam & some head work, after all I’m right there...
I can’t wait to roast the hides off these 20 year old tires!
With the zf6 3.54s are about the best ratio. First gear in the zf6 is a 2.66 ratio which is not low enough, especially for 3.07s. 6th is .5 which is a lot of overdrive. 1st gear and 3.07s with a zf6 would feel like you're starting off in 2nd or even 3rd gear. Then having the .5 o/d with 3.07s you would be at 1100-1200 rpm doing 65 which the engine would not have enough torque to keep it moving at that speed. My 92 with a LT1 6 speed 3.45s does 1600 RPM at 65. If I go up a slight hill I have to downshift into 5th. I have thought about the 3.54s myself and feel that little extra gear could help it be in a better power range in 6th doing 65-70 on the freeway. 80 up the same hill in 6th is no problem. No need to downshift.
Really? I climb PARLEYS CANYON in UT, ever work day. It gains ~2500' elevation over 13 miles, so it is most definitely more than a "slight hill". I'm lacking air -even at the base elevation of Parley's and by the summit, I'm down about 21% tq and hp due to elevation....but my '92 climbs it just fine in 6th gear.
Going from 3.45 to 3.54 is not worth the effort or money. If you're doing a gear change....do a gear change. At least 3.73's!
Originally Posted by Greg Gore
Don't forget... the torque converter in the A4 cars adds a 2:1 to the equation by itself.
I agree on most of your gear analysis. The Viper and my 4+3 do use the 3:07:1 and is ideal for a stock long runner L98. When you modify the TPI intake it
raises usable rpms in the 5,500rpm and if you run them out to 6,000 rpms they can still pull well as a gear shift loses to much time.
Once I go AFR and Mini-Ram will be using the 3:55 gears. If you look back at the 50 fastest muscle cars of all time, the average gear is 3:55.
If you have a 7,000 rpm beast a 3:73 is justified for the street. If you are racing 1/4 mile then maybe 4:11 if its 1/8th mile then maybe even a higher ratio.
Also, once an engine is opened up to breath along with light weight components it revs much quicker and gets to the power band quicker.
Light weight flywheel, pistons, valves etc...
With the zf6 3.54s are about the best ratio. First gear in the zf6 is a 2.66 ratio which is not low enough, especially for 3.07s. 6th is .5 which is a lot of overdrive. 1st gear and 3.07s with a zf6 would feel like you're starting off in 2nd or even 3rd gear. Then having the .5 o/d with 3.07s you would be at 1100-1200 rpm doing 65 which the engine would not have enough torque to keep it moving at that speed. My 92 with a LT1 6 speed 3.45s does 1600 RPM at 65. If I go up a slight hill I have to downshift into 5th. I have thought about the 3.54s myself and feel that little extra gear could help it be in a better power range in 6th doing 65-70 on the freeway. 80 up the same hill in 6th is no problem. No need to downshift.
I agree with your real life experience the 6Sp needs the taller gear. the ratio in the 4+3 make the 3:07 better off the line.
Really? I climb PARLEYS CANYON in UT, ever work day. It gains ~2500' elevation over 13 miles, so it is most definitely more than a "slight hill". I'm lacking air -even at the base elevation of Parley's and by the summit, I'm down about 21% tq and hp due to elevation....but my '92 climbs it just fine in 6th gear.
Going from 3.45 to 3.54 is not worth the effort or money. If you're doing a gear change....do a gear change. At least 3.73's!
I have no plans to change the rear gear. However, you're comparison of how your car climbs a hill makes me wonder even more about the condition of my engine. Mine feels like a turbo vette. It accelerates just fine off the line with plenty of power, but after 3500 RPM it gets a slight boost. I had my idler pulley melt, so changed that and found the PS pulley melted, the A/C clutch broke off and changed all that. It still feels like a turbo vette. So I am going ahead with doing the timing chain. So I wonder if I am lacking power down low where it makes me have to downshift up that hill where I shouldn't have to.
Neat so my old 1985 Z51 had a 3.07 rear with 1st and 2nd being 2.88 and 1.92 respectively, and now my 1989 with the ZF6 and the 3.54 rear and the 2.68 and 1.80 1st and 2nd should actually feel quicker off the line (assuming tires stick).
I've got a 1 way plane ticket out to Iowa tomorrow evening after work, cheap hotel tomorrow night in Des Moines, then hopefully picking the vette up on Saturday. Here is to hoping it is in solid shape and that it is ready for the drive back to Albuquerque!
