If you have a tach, figuring out the ratio in a running car is easy. Just drive it up to some rpm above the stall speed in 3rd gear, note the rpm and mph, and then put the numbers into a gear speed calculator online.
The only common ratios for autos are 2.6, 2.78, 3.02. If your numbers dont come out to one of those, try switching the transfer gear numbers. Like, instead of 52/54, try 54/52. That's the easy mistake to make.
Dont push the red button.You hear me?
I didnt think that any td stock could run 13's from the factory?
---------- Post added at 04:05 PM ---------- Previous post was at 03:56 PM ----------
Edit, correction
My car is 2900 and I weigh 200, so 3100 is where its at.(turns out I was off by 200lbs, scale verified, 2700).
I just did the math and my car(3100lbs) would have to be making right around 270hp at the flyweel to get the times I have. No td ever come like that from the factory that I know of. I realize there are some variables, but that almost 100hp more than stock
Last edited by turboshelbys; 05-27-2019 at 08:21 AM.
I corrected my post to read - 13.88 at 98.19mph is right on target for a fairly stock 5spd VNT Shadow at 14psi. To be accurate, I should be indicating 'stock appearing'.
In two others cases, a fairly stock or stock appearing VNT Shadow consisted of no cat, K&N filter in the production box, a 2.5 T-I muffler (different PN/lower restriction than a VNT muffler) and 14psi.
In your case, almost completely stock consists of a cone air filter, larger I/C, no cat, fwd stage2 comp, drag radials and ground effects removed.
In both cases, the cars appear to benefit from all things modified.
Still - Nicely done.
It sounds like a generous calculation especially for a VNT.
The advertised HP on the VNT was 175, to meet the Turbo-II numbers, but the engine struggled to make 165HP off the showroom floor.
89' vehicles were a bit lighter than their 90' and later counter-parts due to changes in the NHTSA regulations and the resulting changes in vehicle structure and content.
The 3100lbs may be a bit closer to a convertible weight - an 89 CSX should be near 2700-2800 lbs
Does anyone have an accurate weight for a 1989 CSX?
This dragstrip calculator is fun to play with - http://vexer.com/automotive-tools/1-...MPH-calculator
Try 2800lbs or even 2900lbs and you'll be surprised what the resulting HP numbers come in at, for 13.8@98mph.
I think you may have taken the expression 'almost stock' a bit further than I did.
Still - Nicely done.
Sounds like a fun ride.
Last edited by 5DIGITS; 01-22-2012 at 06:37 PM.
Give me the vin # of the car, I can get its weight.
Any calculation coming out to 270hp automatically means that one or more variables is off. Go look for other cases of a turbo with a ~40mm inducer putting out 270hp, the response will be the same everywhere... they can't.
I have a car that is slightly lighter than an 89 csx that dyno'd 210whp and trapped 98mph in 100f+heat index with 7 psi in 1st and 2nd, 16 psi in 3rd and 4th. If I had been able to run full boost the entire 1/4 mile it would not have even taken 210 whp to trap 98.
13s@100mph is still a good result, everyone agrees. But it isn't magical, and it doesn't make 270hp.
Dont push the red button.You hear me?
Edit, correction
My car is 2900 and I weigh 200, so 3100 is where its at.(turns out I was off by 200lbs, scale verified, 2700).
again all the runs were with just the cone air filter, larger i/c, no cat, and stage 2 comp(added 2psi). all the other parts have 130k on them. so when i say almost stock, i think i am right on point. the new stock turbo and a413 have just been put in. even with those i really dont consider this car highly modified.
Last edited by turboshelbys; 05-27-2019 at 08:20 AM.
No, you are accurate. I weighed mine and with me in it on 2 different scales, it was about 2,950 lbs... and I am around 225.
But, a fairly stock VNT on just 14 psi has no business running 13's w/out addressing many other details. (ie: meaning just 2 more psi ain't gonna cut it, especially if using the stock T-IV cooler )
Originally Posted by 22mopar
Steve
'90 VNT competition package Shadow - T-III SC6262 conversion/restoration
'91 Spirit R/T - white
'91 Spirit R/T - white
'92 IROC R/T - red
'67 Barracuda 273 now, 440/727 awaits....
Thats basically what i was getting at. best times i have seen from a stock vnt with sticky tires is 14.5. thats why i was a little thrown by that comment
I think the neon trannys had the 1.04 ratio 45/47. The a413 uses a 53/56 gearset which is 1.06. Just counted mine to double check.
AJ, rounding up your 21/60 ring and pinion would be 2.56 x 1.06 (multiplying) would equal 3.02/3.03 (either rounding up or down). 2.60 final drive if using .91 gears. My 85 NY'er has 2.60 final drive. She's a pooch coming out of the hole (stocker). Shifts into second automatically at 52 MPH @ WOT according to my digital speedo. Probably going to put the 1.06 gearset in.
Todd
Last edited by 4 l-bodies; 01-22-2012 at 08:34 PM. Reason: typo
Mine ran 9.5's on crappy 2.3 60fts (195-60-15 street tires) with a kick-azz 14psi cal, no cat and "ok" aftermarket muffler (stock exhaust piping) and mildly ported head and FM ported exhaust manifold. I guess with a 2.1 that would have netted a low 14 second.
I later on removed the balance shafts and made a couple minimal improvements that would have gained a couple more mph and maybe nip a 13.99... but that is now just speculation.
My other VNT Shadow... same mods (but with balance shafts still in and stock filter/airbox) really ripped once I installed the 3" JRB catless system and Ultraflow muff. Car went crazy in 3rd and 4th gear pulls as it was now boosting beyond the 14psi cal to the tune of 17psi.
Everyone else I know with 14-15 psi and basic mods all ran mid 14s as well....
But whatever everyone else did can't take away that you ran 13's with your car. I'm just wondering at what boost? Because 16-17psi.... then that makes sense to me anyways.
Originally Posted by 22mopar
Steve
'90 VNT competition package Shadow - T-III SC6262 conversion/restoration
'91 Spirit R/T - white
'91 Spirit R/T - white
'92 IROC R/T - red
'67 Barracuda 273 now, 440/727 awaits....
Thank you Steve, thats what I have been getting at.
I have used two different boost gauges and its max boost is 14-15psi on both.
I agree with that.Thats basically what i was getting at. best times i have seen from a stock vnt with sticky tires is 14.5.
The 270hp comment is sort of asking for it. Im not trying to be rude."But it isn't magical" again why this comment? kind of a backhanded compliment.
I think your times are great and i think you're setting a good example for all the VNT whiners (there are a lot of them, i think NAJ on td is the worst).
But it doesnt make 270hp. That's why i added the 'magic' word. Your car would be magical if it ACTUALLY made 270hp on a turbo with a <40mm inducer.
Dont push the red button.You hear me?
The 4 best times I had were all made the night my turbo gave up:
13.67
13.70
13.71
13.72
But at the rate you're going can you stand to leave the stock turbo in there that long? You might get the bug for 12s.. 11s..hopefully my dyno will be up and running this summer and I can get some real #'s. Like I said, I do not like to state hp #'s, timeslips tell the tale.
Dyno numbers would be really cool. There aren't many dynos out there from VNTs.
Dont push the red button.You hear me?
I was right behind him tuning my Dad's wagon. We got to the end of the track and it was like a fog rolled in. We looked to the left where you head back to get your time slip and he looked like James Bond deployed the smoke screen to make his get-away. The best part was finding out they set out the rescue team because they thought he had caught fire.
A.J.
The stock vnt will stay. this is not my race car by any stretch, i am just out to have a little fun with this car untill I am further along in the restoration. Then it will ba a garage queen like my
shelby lancer
http://www.cardomain.com/ride/323133...-shelby-lancer
and glhs
http://www.cardomain.com/ride/3231405/1987-shelby-glhs
My true race car is the 1986 turbo z, but it is still back in michigan. I should have it out here late march then the fun will really start. Who knows, maybe all this testing I am doing on the csx might just involve a future powerplant combo for the Z...
http://www.cardomain.com/ride/209304...-dodge-daytona
That was my move
This was well said - A stock VNT with sticky tires would produce mid 14's but are we discussing a vehicle of this caliber?
I believe we're all on the same page and understand, on the other hand, that an almost stock and equivalently (lightly) modified VNT would yield the times and speeds being discussed.
Respectfully, which comment are you referring to?
Last edited by 5DIGITS; 01-22-2012 at 10:42 PM.
Possibly, but I am positive that people would have posted their times by now. I cannot be the only csx-vnt owner who has done a couple of mods then went to the track. I will never get the comment that "equivalently" modded cars all run the same. If that were true nascar would not be around and we would not have a hobby with these cars. Show me one 1989 csx-vnt that has run a 13.67 or even any 13 second run and I will stop taking offense to comments.
People keep saying to me that what I am doing is nothing special, well then why hasn't anyone else done it?
If you want to give a compliment, then give it, don't slide in and say everyone else could do that too, especially when it has not been done before!