Dare I say fastest VNT powered 1989 CSX

Also, I keep getting emails/pm's saying that its not likely and or impossible to do what I have with a vnt turbo'd car. I have 82 time slips, video's and about 15 TM members who have been at that track and have seen this car go, so please do not tell me what is possible. When I first started racing this car many people said that the vnt does not flow well enough, if I mess with the airbox or exhaust it will overboost, you cannot grainger a vnt, etc. whatever. I have done all these things and the car just runs stronger and stronger. Anyone who want to come check it out anytime feel free, we are at the track almost every weekend. So please, no more junk mail:thumb:

i believe it! I own a csx-vnt with some mods...and it puts down 267 whp and 284 ft/lbs torque. I'm sure it would run mids 13's with sticky tires...

This is pretty cool! Especially since it shows it doesn't take much to have a 13 sec TD, and the VNT's can be fun to play with!

People used to say we couldn't make 500hp on a stock bottom end and the T3 couldn't be made reliable and the Neon head wouldn't fit our blocks, etc etc. I say, do it yourself and prove them all wrong. I love it when someone breaks another barrier with these cars. Good for you!

My point Exactly:dancing:

People were telling me that the car could not do better than 15.1 stock and I ran a 14.52. Then they said I would not be able to get any better than that with the stock vnt turbo. Here I am at 14psi running 13.67 with spinning thru 1st into 2nd. All this with 130k original on the clock, leaking turbo(intake and exhaust side), slipping clutch, and just a couple of basic add-ons.

Wait till I get my new vnt turbo, clutch, new cal., and slicks installedarty1:

I am not posting to disagree/debate/argue with anyone...

I just want to know what you did to stop the boost creep issue.

My VNT is all stock and was fine at the track (15.85 @89.00 in 11/09, 135,000 miles, 100,000 on the clutch) until I had to replace the muffler and wanted a direct fit so I installed a Walker Dynomax and that created boost creep issues in 3rd gear @ 4800 rpm's, I used to hit the stripe in 3rd gear @ 6100 RPM's.
Being a bracket racer I did not really care, just shifted into 4th @ 4700 and raised the dial accordingly, that was fine until the air got really good(-1700' adjusted altitude) and then the boost creep issue was also present in 4th gear.

I corrected the issue by not racing her anymore.

I have not had any over boost issues at all.

I re-ran all my vacuum lines to make sure there was no problems there. Removed the air box, added a cone intake, removed factory intercooler, added and plumbed in a larger intercooler, removed all the exhaust except for the stock downpipe. ran a bunch of 13.9's and best 13.88. Stock comp gave me a max of 13psi, usually settling back down to 11-12psi.

Then added a fwd stage 2 14psi chip. ran a bunch of 13.7's and a best 13.67, but now spinning all the way thru first and most of second.

That's it in a nut shell. I am confident with slicks it would shave off a couple of tenths minimum. Oh, elevation is rt around 1700ft above sea level.

Here is the build up, etc, on it with pics, so you can see what i have done.

http://www.cardomain.com/ride/3921943/1989-shelby-csx

I also had a 2 1990 daytona vnt's and never had the boost creep problem either.

I would seriously go through those vacuum lines, definatly if they are stock, they can be very pesky when trying to control boost issues. First thing I do with every td i get, is remove the factory lines, way overcomplicated in that design.

tryingbe said:

Post those e-mails / PMs!

I put that cylinder head/VNT/Headgasket onto that block and I witness this car doing 13's.

Click to expand...

I'd post those emails up too! We'd probably get a good chuckle out of it. Dang was that head a little crispy looking!


Definitely some good work, and well worth it!

I don't think your success is anything magical.. there just arent that many who have gone out and made 80 passes on a near-stock setup. Most people run crap times on street tires, hit cutout a lot, and then give up.

I do think you won't see MUCH in the way of further mph gains with a stock turbo. Upping the boost will make more torque in the midrange and drop a bit of ET if you have traction, but i am guessing you will not actually make much more high-rpm power or mph by raising the boost.

According to some quick internet calculations you're making about 230hp at the crank, which is pretty much maxed out as far as the airflow that turbo will move according to conventional turbo sizing wisdom.
Ultimately, if the turbo is already flowing about as much as it can, mph gains will only come from reducing weight and parasitic losses.

Although, with a 102 trap i think you could run a REALLY low 13 on slicks.

There is nothing wrong mechanically with my vehicle, the vacuum system has been completely re-done before the muffler was replaced and all was well until the Dynomax was installed.

I also have over 4000 passes down the 1/4 mile and over 500 on my VNT.

The boost creep issue presents itself after prolonged WOT, it will not happen in 1st or 2nd gear because they wind out to quickly.

I am going to say the reason you have not seen any boost creep issues is because of the altitude of 1700' ABOVE sea level.
As I said my issue got worse as the air got better, adjusted altitude of 1700' BELOW sea level.(Track is 30' above sea level)

Unfortunately we will never know unless you go to a track that is at sea level with good air or I go to altitude.

:why:

Again, here is one of the nah-sayers telling me what can't be done with the VNT.

I am not saying there is anything magical or that I have the best set-up and I am definatly not saying that everyone should run out and try what I have with their numbered cars. I bought the car to restore it, but not knowing the history on the motor, trans, clutch, leaking turbo, etc. I decided to run it at the track until something gave up or until I did no see anymore gains.

As far as I am aware, nobody has come this far with their CSX-VNT. I have had people say what their cars would do, but no time slips or videos have shown up yet. I am just showing what my car does do period.

Will you be here telling me I cant hit the 12's with a stock vnt turbo too?

Sorry NAJ, this was meant for the one above you.

When I raced in Michigan with my vnt daytona's I never had the boost creep either. Both of those cars had the stock comp. I guess I must have dumb luck as far as boost creep. I must say though that the fwd comp. really sticks the boost in place on my CSX. Are you running the factory intercooler?

I am not saying it cannot be done and I actually applaud your ET's especially at altitude.
I was only asking what you did to stop the turbine side from overspooling and you said you had no such issues.
I was only offering a reasonable explanation why you are not experiencing the boost creep issues.

Others chimed in and said my problem is vacuum related and suggested I have no experience at the track which I disagree with completely.
NOBODY maintains their vehicle like I do so i know the issue is not vacuum related.

Posted after you, did not see your post

No problem NAJ, good questioning is what leads to answers:thumb:


I actually have made 3 runs at 104mph and one at 104.87mph. These we all 14-14.2sec launching from second gear.

I can say that on this car that the turbo has been leaking from both sides, intake and exhaust so that might be why I have not had the boost creep on it. Time will tell with the new vnt turbo I am installing this week.