Driving my Turbo MS3 XJ!
Posted: August 18th, 2018, 8:01 pm
Got the jeep running boost for real this weekend. Last weekend got the rest of the hardware done- wastegate, charge piping, odds and ends. It built a little bit of boost on the lightest wastegate spring (turned out to be 3psi) however the stock injectors ran out of fuel just as the turbo started spooling up.
Was hoping for a trip to the track yesterday but got rained out. Got a whole bunch of stuff finished in preparation, most notably a set of ebay 80lb injecotrs. They are copies of some oe injectors, I figured for a 1/3 the price of the real deal they were worth a shot. They are working great so far! After retuning the fuel map they are performing exactly as I want them to.
Yesterday this was the progress I made in terms of making the jeep faster-
-Got the injectors tuned in and was able to rev the 3 psi spring all the way out, felt cool and probably 20 hp better but not fast yet
-Fixed the last remaining (I hope) exhaust leak and improved spool and the turbo could be heard more clearly
-Swapped in a 2 steps stiffer spring. Cheesy wastegate came with 4 UNLABLED springs that ALL can be concurrently installed. 2nd stiffest spring in its own made 6 psi on the minimum preload setting, went up to about 8 with the adjuster cranked all the way.
-After swapping springs we were able to get a better idea of how the turbo was spooling, which was/is... suboptimal. It started building boost around 3500 rpm, with the wastegate opening around 4200 or so. Started pulling HARD at 4k. It has real power, however with boost coming in after peak torque it's not so usable. Not really enough area under the curve.
-Also went to a 180 tstat from a 195, made the driving experience FAR better.
Tonight I took the jeep out after the sun went down and HOLY COW does cool night air (and no passenger) make a difference. I also swapped in the lightest spring on top of the 2nd heaviest, it made 9 pounds today. Doing pulls in third, it sucks you down into the seat and holds you there. It's FAST. Its quite a strange and new feeling. If I HAD to put a number on it, I'd estimate 100 whp more than stock. The cool dense air let it build a pound or 2 around 3k as well and helped out the powerband a bit.
To help bring the boost threshold down a bit, I'm going to wrap the rest of the exhaust- it's wrapped about 1/3 of the way down now. To have a usable powerband, full boost needs to hit at 3500 or lower and being able to build a few below 3k would make it lots of fun on the street.
Can't wait to take it to the track. The eventual goal for the jeep is 12s, and honestly I don't think it's going to be that hard. Couple pounds of boost and a little more timing combined with power from 3500 to 5200 and it's a rocket. If i can cut a 13.50 on crappy old street tires it's a 12 second car on slicks.
Moral of the story- build something awesome that no one has done before on minimal budget! Once you're leaning things and making the '69 chevelle crowd angry, you're going in the right direction. Also, rear mount turbos WORK.
Was hoping for a trip to the track yesterday but got rained out. Got a whole bunch of stuff finished in preparation, most notably a set of ebay 80lb injecotrs. They are copies of some oe injectors, I figured for a 1/3 the price of the real deal they were worth a shot. They are working great so far! After retuning the fuel map they are performing exactly as I want them to.
Yesterday this was the progress I made in terms of making the jeep faster-
-Got the injectors tuned in and was able to rev the 3 psi spring all the way out, felt cool and probably 20 hp better but not fast yet
-Fixed the last remaining (I hope) exhaust leak and improved spool and the turbo could be heard more clearly
-Swapped in a 2 steps stiffer spring. Cheesy wastegate came with 4 UNLABLED springs that ALL can be concurrently installed. 2nd stiffest spring in its own made 6 psi on the minimum preload setting, went up to about 8 with the adjuster cranked all the way.
-After swapping springs we were able to get a better idea of how the turbo was spooling, which was/is... suboptimal. It started building boost around 3500 rpm, with the wastegate opening around 4200 or so. Started pulling HARD at 4k. It has real power, however with boost coming in after peak torque it's not so usable. Not really enough area under the curve.
-Also went to a 180 tstat from a 195, made the driving experience FAR better.
Tonight I took the jeep out after the sun went down and HOLY COW does cool night air (and no passenger) make a difference. I also swapped in the lightest spring on top of the 2nd heaviest, it made 9 pounds today. Doing pulls in third, it sucks you down into the seat and holds you there. It's FAST. Its quite a strange and new feeling. If I HAD to put a number on it, I'd estimate 100 whp more than stock. The cool dense air let it build a pound or 2 around 3k as well and helped out the powerband a bit.
To help bring the boost threshold down a bit, I'm going to wrap the rest of the exhaust- it's wrapped about 1/3 of the way down now. To have a usable powerband, full boost needs to hit at 3500 or lower and being able to build a few below 3k would make it lots of fun on the street.
Can't wait to take it to the track. The eventual goal for the jeep is 12s, and honestly I don't think it's going to be that hard. Couple pounds of boost and a little more timing combined with power from 3500 to 5200 and it's a rocket. If i can cut a 13.50 on crappy old street tires it's a 12 second car on slicks.
Moral of the story- build something awesome that no one has done before on minimal budget! Once you're leaning things and making the '69 chevelle crowd angry, you're going in the right direction. Also, rear mount turbos WORK.