Discussion
I've heard alot of praise for the amount of low end power on the turbo Esprit despite making most of its power in the upper range, but mine seems lacking in that area. I am not able to take off very quickly at all, until around 3000 rpm where the turbocharger kicks in. Is this an issue with anyone else? My turbocharger is upgraded and is larger the original, which I know should diminish low end power somewhat, but it doesn't seem reasonable to cause a power loss like this. Its fine after 3000rpm, however, which is the point at which the car snaps your head off 
This wouldn't be an issue for me if I hadn't heard from numerous sources how good low end power was, but any suggestions are welcome. Does anyone else have a problem with this? By the way, mine is an 86 turbo with bosch k-jettronic injection
Dan
This wouldn't be an issue for me if I hadn't heard from numerous sources how good low end power was, but any suggestions are welcome. Does anyone else have a problem with this? By the way, mine is an 86 turbo with bosch k-jettronic injection Dan
Dan,
The 4-cyl cars and especially those which pre-date the GM Engine Mgmt. System really lack some low end by comparison. There are several things which you can do.
First, do a compression/leakdown test to insure that everything is tight. This is essential for low-end power. If you have bad valve seals, valve guides, piston rings, these will significantly rob low end power. Once the engine is 'on-cam', there is enough 'flow' to overcome any leaks, but down low, any looseness will merely rob power.
Next, you can purchase and install a 104° Pulley on your intake cam ($160). Your intake cam has been retarded for emissions purposes and currently has a 110° pulley on it (°/crankshaft rotation). Doing this swap allows the engine to breathe easier and, as it was originally designed. The 110° pulley was a quick emissions fix for the US market only.
Next, you can advance the timing as far as 30° BTDC, this will make a good improvement along the entire power band. As is, you only have about 10° of advance available through distributor rotation before you hit the oil filter w/ the vacuum advance module. To gain additional advance, you must shift the aux. shaft pulley on the timing belt, not difficult, but time consuming. Also, if you do this, you will want to plan replacement of all 'V' belts and the timing belt as you have to remove them to rotate the aux. shaft pulley anyway.
Next, you can purchase and install a 104 cam for the intake ($150). This is a mildly more agressive cam (0.412" lift vs. 0.378" stock) and improvements are felt through the entire RPM range. This cam helps significantly w/ the 3k RPM transition.
Finally, you can port the head to match the runners on the intake manifold. There is easily a 1/8" - 1/4" difference between the ID on the port openings in the head and the ID of the intake runners on the manifold. Opening these will make the engine seem like an entirely different animal.
If all these mods are done, you will easily be able to run with a stock SE and you'll probably gain a 25-30% increase in low-end torque. Hope this helps. Happy Motoring! Jim'85TE
The 4-cyl cars and especially those which pre-date the GM Engine Mgmt. System really lack some low end by comparison. There are several things which you can do.
First, do a compression/leakdown test to insure that everything is tight. This is essential for low-end power. If you have bad valve seals, valve guides, piston rings, these will significantly rob low end power. Once the engine is 'on-cam', there is enough 'flow' to overcome any leaks, but down low, any looseness will merely rob power.
Next, you can purchase and install a 104° Pulley on your intake cam ($160). Your intake cam has been retarded for emissions purposes and currently has a 110° pulley on it (°/crankshaft rotation). Doing this swap allows the engine to breathe easier and, as it was originally designed. The 110° pulley was a quick emissions fix for the US market only.
Next, you can advance the timing as far as 30° BTDC, this will make a good improvement along the entire power band. As is, you only have about 10° of advance available through distributor rotation before you hit the oil filter w/ the vacuum advance module. To gain additional advance, you must shift the aux. shaft pulley on the timing belt, not difficult, but time consuming. Also, if you do this, you will want to plan replacement of all 'V' belts and the timing belt as you have to remove them to rotate the aux. shaft pulley anyway.
Next, you can purchase and install a 104 cam for the intake ($150). This is a mildly more agressive cam (0.412" lift vs. 0.378" stock) and improvements are felt through the entire RPM range. This cam helps significantly w/ the 3k RPM transition.
Finally, you can port the head to match the runners on the intake manifold. There is easily a 1/8" - 1/4" difference between the ID on the port openings in the head and the ID of the intake runners on the manifold. Opening these will make the engine seem like an entirely different animal.
If all these mods are done, you will easily be able to run with a stock SE and you'll probably gain a 25-30% increase in low-end torque. Hope this helps. Happy Motoring! Jim'85TE
Dan,
You can get these parts from any of the usual sources. I got mine from Jeff Robinson @ JAE www.jaeparts.com/ , the prices I quoted were at least a year old, when I got my parts, so expect a change somewhat.
As far as passing CA Emissions Testing, I cannot say for certain, because there is no testing in my state at all. But, if I had to guess, I would say Yes. You are still keeping the Cat and these mods result in more complete combustion. I wouldn't be too surprised to see your emissions test possibly improve, but, again, as I said, I am not certain. Jeff is in CA, so possibly he could shed more light. Happy Motoring! Jim'85TE
You can get these parts from any of the usual sources. I got mine from Jeff Robinson @ JAE www.jaeparts.com/ , the prices I quoted were at least a year old, when I got my parts, so expect a change somewhat.
As far as passing CA Emissions Testing, I cannot say for certain, because there is no testing in my state at all. But, if I had to guess, I would say Yes. You are still keeping the Cat and these mods result in more complete combustion. I wouldn't be too surprised to see your emissions test possibly improve, but, again, as I said, I am not certain. Jeff is in CA, so possibly he could shed more light. Happy Motoring! Jim'85TE
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