Upgrading Turbo
Discussion
I am in the middle of an engine rebuild on my 88 esprit w/ bosch f.i, after a look at the turbo I figured I will have to replace it, there are a couple small chips in the impeller on the exhaust side. I am considering going to a hybrid garret t3/04 turbo w/ a .48 inlet housing.I know the downpipe will have to be altered and a different hose to the intake will have to be fitted. I am also considering adding an intercooler. I guess my question is has anyone done this, and if so how has it turned out? Any suggestions?
Happy Boosting
Dino
Happy Boosting
Dino
There is a easy way and a hard way on your car.
The easy way, you will lose your A/C. You will use the plumbing and radiator from the system for the chargecooler. You use a electric pump to circulate the coolant. This has been done to cars where A/C was not a concern and used for more of a track car.
The hard way, you will need to run coolant lines, add a small radiator up front, etc.
I have only seen this done to the 89 non SE Delco injected car, so I don't know how the Bosche mechanical injection device will like it.
Calvin
The easy way, you will lose your A/C. You will use the plumbing and radiator from the system for the chargecooler. You use a electric pump to circulate the coolant. This has been done to cars where A/C was not a concern and used for more of a track car.
The hard way, you will need to run coolant lines, add a small radiator up front, etc.
I have only seen this done to the 89 non SE Delco injected car, so I don't know how the Bosche mechanical injection device will like it.
Calvin
I am in the middle of an engine rebuild on my 88 esprit w/ bosch f.i, after a look at the turbo I figured I will have to replace it, there are a couple small chips in the impeller on the exhaust side. I am considering going to a hybrid garret t3/04 turbo w/ a .48 inlet housing.I know the downpipe will have to be altered and a different hose to the intake will have to be fitted. I am also considering adding an intercooler. I guess my question is has anyone done this, and if so how has it turned out? Any suggestions?
Happy Boosting
Dino
Dino,
What aims are you trying to achieve? There are better, more efficient and more reliable ways of enhancing the car's performance than putting some 'Honker' turbo on it, the Bosche K-Jetronic isn't easily adaptable to merely adding a larger turbo and intercooler. How are you planning to increase the fuel supply? If done incorrectly, you'll melt the pistons in your newly rebuilt engine in a relatively short time. Also, merely adding an oversize turbo can give driveability and reliability problems you may not have taken into account.
A better route would be to work on the cams and head to make the engine breathe easier and get more use from the boost you already have. Happy Motoring! Jim'85TE
Lotusguy,
Do you suggest that I rebuild my oem turbo and mill the head. I have also seen different cam wheels for the car. I am just wanting to squeeze an extra 40-50 h.p out of it safely. How much boost is safe to run. Our gas here in Canada is 94 octane.
Thanx for the input guys
Dino
Do you suggest that I rebuild my oem turbo and mill the head. I have also seen different cam wheels for the car. I am just wanting to squeeze an extra 40-50 h.p out of it safely. How much boost is safe to run. Our gas here in Canada is 94 octane.
Thanx for the input guys
Dino
espritnutdean said: Lotusguy,
Do you suggest that I rebuild my oem turbo and mill the head. I have also seen different cam wheels for the car. I am just wanting to squeeze an extra 40-50 h.p out of it safely. How much boost is safe to run. Our gas here in Canada is 94 octane.
Thanx for the input guys
Dino
Dino,
"Just wanting to squeeze an extra 40-50 H.P. out of it"??????
You say this so casually, as if it's just as simple as switching to a higher wattage lightbulb. There is virtually no way to see a 50 HP increase in a Bosche injected 910 engine used for the street.
It would be so expensive to port the head, bore it out to accept bigger valves, add a custom header (no off the shelf unit is available), balance and blueprint the engine, add DS2 Cams or something maybe even more radical, change the fuel pumps, install larger and/or secondary injectors, upgrade the ConRod bolts, custom map the airflow meter, adjust the wastegate, increase the cooling and lubricating capacity that it'd be just cheaper and more reliable to find an S4s engine to install instead. Add to that that the tranny will barely take the added strain.
10-15 HP is available by porting the heads and increasing the valve lift with either a 104 cam or DS2 cams. Maybe another 3HP can be extracted by additional intercooling. As I said, anything more and you will have an engine with an extremely shortened lifespan, or you'll be blowing tranny's right and left.
You don't have a high horsepower car in the Esprit. You have a car which can deliver sterling performance with a minimum of horsepower. That is not to say that significant improvements in performance and driveability can't be derived from simply porting the head, adding a slightly higher lift cam. Sure, a hybrid turbo and intercooling can add to that, but the cost and inconvenience make it a poor cost/benefit. Happy Motoring! Jim'85TE
espritnutdean said: Lotusguy,
Do you suggest that I rebuild my oem turbo and mill the head. I have also seen different cam wheels for the car. I am just wanting to squeeze an extra 40-50 h.p out of it safely. How much boost is safe to run. Our gas here in Canada is 94 octane.
Thanx for the input guys
Dino
Dino,
I would rebuild your oem turbo and have the head ported. The intake and exhaust manifold runner openings are about 1/8-1/4" larger than the ports in the head. Opening the head ports to match will improve the performance of the engine by a surprising margin.
As far as changing Cam pulleys, the 907/910 engine was originally spec'd for a 104° (identifiable by a Green Dot)pulley on the intake cam. Later, due to emissions requirements, Lotus retarded the timing further by using a 110° pulley (identifiable by a Red Dot). On the earlier models, Lotus merely swapped the intake cam pulley (104°) with the auxillary shaft pulley (110°). This made it easy, and free, to swap the pulleys and re-establish the correct valve timing. On the later models, you need to purchase a 104° (Green Dot) pulley and swap it with the intake cam pulley. Alignment on the timing belt remains the same.
One note about milling the head. This should be done as part of any engine rebuild as it is aluminum and does warp with time. Care should be taken to insure that the head is milled no more than 0.040". Any further milling makes the head unserviceable and it must be replaced. If milling the head, be sure that it has not been previously milled so you do not exceed this maximum value. Milling the head more than this amount upsets the timing values and exceeds the amount of clearance necessary to avoid valve contact with the piston domes. Happy Motoring! Jim'85TE
espritnutdean said: Jim,
I did read somewhere about the green dot cam wheels, Does JAE carry these cam wheels? As the head is off now, I will have it ported. Is there anything I will have to do to the Bosche F.I to cope w/ the better breathing? Thanks for the help.
Cheers,
Dino
Dino,
Jeff can supply the green dot pulley you need. You only need one as there is little benefit to fitting on on the exhaust cam.
As far as the Bosche FI, you can replace the injectors with higher flow ones, but this necessitates a look at the fuel pump and fuel pressure regulator as well. I don't know of an off the shelf spec for you to use. If you erally want this, it's best to determine the flow rates you require on a 'Rolling Road' or Dynomometer, using several different injectors and going with the ones which perform best over the operating range of the engine. Happy Motoring! Jim'85TE
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