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Wedge TR8 PERFORMANCE INCREASE

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bluemiata90

bluemiata90

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To much information can sometimes be more confusing, but here goes. I'm considering adding a 4 barrel conversion kit to my stock TR8. I'm looking for more low end power and more quick response. How much more power will a 4 barrel kit give me, do I have to add headers to benefit from the 4 barrel?. Any information or opinions will be greatly appreciated as the conversion is not cheap and I really don't want to invest that kind of money and not get the increase in low end power.
 
Good question Scott, unfortunately, one that I've never seen an answer to. I think the reason most of us make the switch is less for a performance gain than for simplicity and reliability. Actually, I definitely think I've seen a performance gain with my Edelbrock since I was never able to get my Strombergs dialed in, but that's a very subjective opinion.

The Stromberg setup is supposed to be quite efficient when set up properly but that's big IF. Somebody out there must have some dyno results.

Tom
 
I went with the Holley 390, a mild Sig Erson cam, and headers. Have no idea what the HP gain was, but sure felt it!

Best guy to answer your question with specifics, though, would be Woody at the Wedge Shop.

Mickey
 
I started with the Holley 390 but could never tune it so I sold it on ebay, made enough to buy a Eldebrock and other new parts. The Eldebrock is easy to tune very forgiving. Even this week I had a neighbor fine tune it even more and it seems to get better yet
 
Thanks for the replies. Does anyone have Edelbrock/Holley 4 barrel conversion on their otherwise STOCK TR8. I know it includes a Edelbrock intake with a Holley rejetted carb.. I'm leaning towards buying that setup. If you do, hows the increase.
 
Look at add-ons as a system. You can get bigger carbs and better flowing intakes but if you can't get the exhaust out of the engine, it's wasted money. Find a system or at least a good PLAN. Good intake, carb, cam, headers, free flowing exhaust, etc...... There isn't a right answer to this question. A lot of things go into making more horsepower and alot of it is trial and error.
grin.gif
 
Doesn't the how to upgrade book say it's good for 30hp on its own? I'm going out or I'd find the reference and cite it.
 
Who in here has ever run their 8 on a dyno and what were the results? I think it would be interesting to get some base ideas of what the HP the mods do for us
 
I am honestly afraid to run mine on there to find out after all the work I have done and comments I get from friends who have ridden in it with me telling me who fast it is that I will come up with some numbers like 98 at the rear wheels
 
depends on the dyno.
QF 650 on a well modded 4.0 (was with Woody when he said it felt strong for a 4.0), I got 225rwhp and 168rwhp on two mustang dynos in less than a week.

No changes btw the two, both corrected, different shops.

Second # was on the same dyno my 6 got 125rwhp after tuning, and I trust them to know what they were doing way more than the 1st place - they are a no BS sorta place.

I also got 89rwhp from the first place when the car was leaned out on a holley 600 (19-20 afr at WOT). That was how I bought it. That was depressing...

Car was running 9's afr 2800-4500 for the second two runs, so I know that it wasn't optimal. When I get back from Mi this weekend, I'm changing out the carb and it's going back with something smaller - a 450 - to see what I can ~really~ get out of it.
 
I've got the Edelbrock/Holley on stock TR8 only other mod is headers. Car has about 50k on it still with the stock cam. Car is noticeably quicker (to me anyway) with the manifold and carb change. Money well spent. Got my kit from Woody who uses the Holley 650 and jets it appropriately for the engine.

Chris
 
Chris, It sounds like you have just the setup I'm looking for. I have decided that the headers would be a must to get the engine to breath better. Do you notice better lowend torque or mid to high range. How hard was it to install and set the carb. Are there any surprises that you found with this setup that I should know about before I purchase it.
thanks
 
If you do decide to go the header route,either have someone do it or do yourself ,the grinding of the HUGE lip on each of the ports. Mount those baby's up the heads ,torque em down and you will bend the flanges.
 
The only surprise is the lack of a port for the small coolant return that's in the triangular boss on the original manifold. If you get the setup from Woody, get him to tap the corresponding area for you. You can re-use the little nipple from the stock manifold, if you can remove it without breaking - very brittle.

You'll also have to run the heater line under the Edelbrock.

I shortened the stock accelerator cable and fashioned a bracket from stock pieces. Hookup on the Holley is pretty straighforward, but you may have to hunt for proper linkages. This Linkage is on my to-do list, but the temporary setup I put together seems to work OK.

Electric choke's no problem - just source a hot wire and ground it to the carb body.

Be sure to observe the proper tightening sequence on the manifold.

And you may want to spray it with a coat of clear paint to make it easier to keep clean.

Can't think of any other issues - really an easy fit.

:cheers:
Mickey
 
Mickey's right, no real surprises. Woody even has installation and set-up instructions on his website and is also available for "tech support" (no need to call India) should you need him. Took me an afternoon at a leisurely pace.
Fired easily with minimal adjustments (mostly idle speed), and I've been very happy ever since the installation. Car starts easily without fuss and drives so much better.

I had a little problem with my carb sticking and not wanting to return to idle smoothly, but solved easily with a new exact-sized throttle cable from Woody.

Also on the headers -- I bought mine from Ted and was also concerned about the "flange" and the need to grind it down before installation. He specifically said don't do it, just bolt them up with the gasket and that's all that was needed.

For me, I notice the difference in mid-range and high-demand situations when the secondaries open. A real kick-in the pants that you don't get off standard carbs.

Good luck,

Chris
 
Regarding the headers, the flange does interfere with access to the head bolts. I ground that area down a bit, but just enough to provide better access.

But then, if you're going to pull the heads, the headers have to come off anyway. I was mainly concerned with re-torqueing after break-in.
 
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