Need to maintain my Buick pride

[BJM]

I have a guy who works for me who loves Miatas, he put a turbo kit on a 2001 Miata and at 9 psi he feels its as fast as my Buick. I have no reason to doubt him. His buddy put a turbo on an older Miata and just pulled a 13.4@102 at a local strip. Since then he has upped his boost slightly and is probably around 13.2 or so.

My car is mostly stock. Cold air intake, Translator +, Jay Carter chip, Hooker exhaust. I still run a cat and would like to keep it. According to my GTech I run 14.5@104 to 105 because of my open differential. The time doesn't bother me but I want to be able to take the guy from a roll.

I can't let a little Miata handle better and be faster too! What should I look at doing next to my car. I was thinking maybe a downpipe and an Extender chip. What about valvle springs, my car has original springs and is at 60000 miles. Any suggestions?

 

[microELVIS]

hmmmmm

well from my experience, your cat will hurt you after say 90 k/hr or so. You say stock, you could change your fuel pump and up your boost but make sure you have a boost guage for that.

I dont think valve springs will help if your top end is still strong, but you can easily take one spring out and have it measured and if its low you may have an option there.

For a quick spool up there is a new grainger valve being sold on this site. I just got it and it makes the car spool very very well from a roll.

I suggest only getting a thdp if you are gonna go that way, ive tried others and it dont make much difference unless you go all out like the terry houston. You'll probably have to do something about your cat anyway with a new dp.

I think you're 14.50 ET because your launches are light, but your mph seems good. I wouldnt worry too much, see what little tricks you can do.

..........Pete

 

[BJM]

Thanks for the reply. I have in fact replace the fuel pump and have an adjustable regulator. I also have a Scanmaster and TurboLink. I also have a good boost gauge.

Other than the basic good maintenance items I have not modified the engine at all.

 

[microELVIS]

Coo

Thats coo, then I would recommend you email the guy with the grainger valve. He will explain it and its not too expensive.

dcc@japan.com

 

[OKTurbo]

Valve springs certainly wouldn't hurt.

With what you have (and I know you don't want to hear this) the best thing for performance would be to get rid of the catalytic converter...or at least get a hi-flow cat-con.

Read any of the "stock" recipes on www.gnttype.org and you'll see "drain the tank...put in race gas....and crank up the boost"

With a tank of 115 octane leaded gas you'll be able to tune for 19-20 psi with the stock turbo etc. You'll be knocking down low low low 13's if you have decent traction. But....the race gas will kill your catalytic converter.

You won't believe how much faster the car will be at 20 psi of boost. Boost is your friend....

John

 

[JDSfastGN]

Just remember that a Gtech mphs about 3 to 4 mph high most of the time, so you maybe at 101 or so. Get a terry houston DP and a posi put it along with gutting the cat at or putting in a test pipe. For a cheap mod that seems to work you can get yourself an RJC power plate for under 100 or so and maybe tune a little more boost out of your car. Good luck

 

[gn1220]

I would spend the money on a posi. All the power in the world is useless if you can't hook One of the best mods to my car was a set of slicks.

 

[equalizer442]

go get your self a posi unit and then go with a larger turbo, te44 at the least but i would recomend to go bigger. i like my te44 and all but if i was to do it again i would have grabed a higher stall and larger turbo. dont forget about the injectors.

 

[BJM]

Is there any point getting a turbo without first getting the downpipe?

I hear people saying that porting the stock elbow can do good things. Is this worthwhile.

I want to keep my cat but I am not opposed to a high flow unit assuming they work that is.

 

[equalizer442]

Is there any point getting a turbo without first getting the downpipe?

yes, did wonders for my car once i got it tuned properly and im still on a stock unported elbow.

 

[microELVIS]

even so

you still seem in good shape, but all sings point to the cat. Highflow cats do work, and the beauty is you can always turn down the fuel for your etest.

I think the guys are right, posi is a good idea. May even up the value of your car.

I was called stupid once on irc for asking if a gn some guy was selling had a posi.

 

[tom h]

Originally posted by BJM
My car is mostly stock. ... I still run a cat and would like to keep it.

Around 12 years ago I installed a dual exhaust w/ Dynomax Superturbo mufflers on my essentially stock '87... no difference felt. Then I replaced the stock cat with a "test pipe", enormous improvement on the "butt dyno" felt. Tires would break loose even at 20 mph roll, something I could never do before. First time at track with the test pipe, my MPH improved from 98 to 102, just from eliminating the stock cat.

So ... ditch the stock cat, either by using a test pipe or one of the new "high flow" cats. I have no experience with the "high flow" units, don't know how it'd compare to test pipe.

 

[BJM]

I will probably switch to a high flow cat then, I would like to keep one on there. I have a test pipe I can try to at least see what its like. Might be addictive though.

I never realized a different turbo would be worthwhile until I changed the downpipe. Maybe I have to think about that.

I will probably port my stock elbow if nothing else.

I started down the used posi path but got derailed when the gears were missing some teeth. I figured it was just simpler to buy an Eaton unit brand new.

Thanks for the comments.